commit

README.adoc

@@ -144,4 +144,4 @@ Variables and functions can be added to a context both programmatically and ad a
 
 == Expressions syntax
 
-See https://cdn.paas.portale-stac.it/howto/go-pkg/expr/doc/Expr.html[Expr documentation] for a complete reference of the expression syntax and available functions.
+See #TODO link to doc/Expr.html#

ast.go

@@ -7,10 +7,14 @@ package expr
 import (
 	"errors"
 	"strings"
-
-	"git.portale-stac.it/go-pkg/expr/kern"
 )
 
+type Expr interface {
+	Eval(ctx ExprContext) (result any, err error)
+	eval(ctx ExprContext, preset bool) (result any, err error)
+	String() string
+}
+
 //-------- ast
 
 type ast struct {
@@ -22,71 +26,66 @@ func NewAst() *ast {
 	return &ast{}
 }
 
-func (ast *ast) TypeName() string {
-	return "Expression"
-}
-
-func (ast *ast) ToForest() {
-	if ast.root != nil {
-		if ast.forest == nil {
-			ast.forest = make([]*term, 0)
+func (self *ast) ToForest() {
+	if self.root != nil {
+		if self.forest == nil {
+			self.forest = make([]*term, 0)
 		}
-		ast.forest = append(ast.forest, ast.root)
-		ast.root = nil
+		self.forest = append(self.forest, self.root)
+		self.root = nil
 	}
 }
 
-func (ast *ast) String() string {
+func (self *ast) String() string {
 	var sb strings.Builder
-	if ast.root == nil {
+	if self.root == nil {
 		sb.WriteString("(nil)")
 	} else {
-		ast.root.toString(&sb)
+		self.root.toString(&sb)
 	}
 	return sb.String()
 }
 
-func (ast *ast) addTokens(tokens ...*Token) (err error) {
+func (self *ast) addTokens(tokens ...*Token) (err error) {
 	for _, tk := range tokens {
-		if _, err = ast.addToken(tk); err != nil {
+		if err = self.addToken(tk); err != nil {
 			break
 		}
 	}
 	return
 }
 
-// func (expr *ast) addToken(tk *Token) (err error) {
-// 	_, err = expr.addToken2(tk)
-// 	return
-// }
+func (self *ast) addToken(tk *Token) (err error) {
+	_, err = self.addToken2(tk)
+	return
+}
 
-func (ast *ast) addToken(tk *Token) (t *term, err error) {
-	if t = newTerm(tk); t != nil {
-		err = ast.addTerm(t)
+func (self *ast) addToken2(tk *Token) (t *term, err error) {
+	if t = newTerm(tk, nil); t != nil {
+		err = self.addTerm(t)
 	} else {
-		err = tk.Errorf("unexpected token %q", tk.String())
+		err = tk.Errorf("No term constructor for token %q", tk.String())
 	}
 	return
 }
 
-func (ast *ast) addTerm(node *term) (err error) {
-	if ast.root == nil {
-		ast.root = node
+func (self *ast) addTerm(node *term) (err error) {
+	if self.root == nil {
+		self.root = node
 	} else {
-		ast.root, err = ast.insert(ast.root, node)
+		self.root, err = self.insert(self.root, node)
 	}
 	return
 }
 
-func (ast *ast) insert(tree, node *term) (root *term, err error) {
+func (self *ast) insert(tree, node *term) (root *term, err error) {
 	if tree.getPriority() < node.getPriority() {
 		root = tree
 		if tree.isComplete() {
 			var subRoot *term
 			last := tree.removeLastChild()
-			if subRoot, err = ast.insert(last, node); err == nil {
+			subRoot, err = self.insert(last, node)
 			subRoot.setParent(tree)
-			}
 		} else {
 			node.setParent(tree)
 		}
@@ -99,32 +98,28 @@ func (ast *ast) insert(tree, node *term) (root *term, err error) {
 	return
 }
 
-func (ast *ast) Finish() {
-	if ast.root == nil && ast.forest != nil && len(ast.forest) >= 1 {
-		ast.root = ast.forest[len(ast.forest)-1]
-		ast.forest = ast.forest[0 : len(ast.forest)-1]
+func (self *ast) Finish() {
+	if self.root == nil && self.forest != nil && len(self.forest) >= 1 {
+		self.root = self.forest[len(self.forest)-1]
+		self.forest = self.forest[0 : len(self.forest)-1]
 	}
 }
 
-func (ast *ast) Eval(ctx kern.ExprContext) (result any, err error) {
-	defer func() {
-		if r := recover(); r != nil {
-			if errVal, ok := r.(error); ok {
-				err = errVal
-			} else {
-				err = errors.New("unexpected error while evaluating the expression")
-			}
-		}
-	}()
+func (self *ast) Eval(ctx ExprContext) (result any, err error) {
+	return self.eval(ctx, true)
+}
 
-	ast.Finish()
+func (self *ast) eval(ctx ExprContext, preset bool) (result any, err error) {
+	self.Finish()
 
-	if ast.root != nil {
-		// initDefaultVars(ctx)
-		if ast.forest != nil {
-			for _, tree := range ast.forest {
-				if result, err = tree.Compute(ctx); err == nil {
-					ctx.UnsafeSetVar(kern.ControlLastResult, result)
+	if self.root != nil {
+		if preset {
+			initDefaultVars(ctx)
+		}
+		if self.forest != nil {
+			for _, root := range self.forest {
+				if result, err = root.compute(ctx); err == nil {
+					ctx.setVar(ControlLastResult, result)
 				} else {
 					//err = fmt.Errorf("error in expression nr %d: %v", i+1, err)
 					break
@@ -132,12 +127,10 @@ func (ast *ast) Eval(ctx kern.ExprContext) (result any, err error) {
 			}
 		}
 		if err == nil {
-			if result, err = ast.root.Compute(ctx); err == nil {
-				ctx.UnsafeSetVar(kern.ControlLastResult, result)
+			result, err = self.root.compute(ctx)
 		}
-		}
-		// } else {
-		// 	err = errors.New("empty expression")
+	} else {
+		err = errors.New("empty expression")
 	}
 	return
 }

ast_test.go

@@ -1,7 +1,7 @@
 // Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
 // All rights reserved.
 
-// t_ast_test.go
+// ast_test.go
 package expr
 
 import (
@@ -44,10 +44,10 @@ func TestAddTokensBad(t *testing.T) {
 func TestAddUnknownTokens(t *testing.T) {
 	tk0 := NewToken(0, 0, SymPercent, "%")
 
-	wantErr := errors.New(`unexpected token "%"`)
+	wantErr := errors.New(`No term constructor for token "%"`)
 
 	tree := NewAst()
-	if _, gotErr := tree.addToken(tk0); gotErr != nil && gotErr.Error() != wantErr.Error() {
+	if gotErr := tree.addToken(tk0); gotErr != nil && gotErr.Error() != wantErr.Error() {
 		t.Errorf("err: got <%v>, want <%v>", gotErr, wantErr)
 	}
 }

bind-expr-functions.go

@@ -1,63 +0,0 @@
-// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
-// All rights reserved.
-
-// function.go
-package expr
-
-import (
-	"git.portale-stac.it/go-pkg/expr/kern"
-)
-
-// ---- Linking with Expr functions
-type exprFunctor struct {
-	kern.BaseFunctor
-	params []kern.ExprFuncParam
-	expr   Expr
-	defCtx kern.ExprContext
-}
-
-func (functor *exprFunctor) GetParams() (params []kern.ExprFuncParam) {
-	return functor.params
-}
-
-func newExprFunctor(e Expr, params []kern.ExprFuncParam, ctx kern.ExprContext) *exprFunctor {
-	var defCtx kern.ExprContext
-	if ctx != nil {
-		defCtx = ctx
-	}
-	return &exprFunctor{expr: e, params: params, defCtx: defCtx}
-}
-
-func (functor *exprFunctor) TypeName() string {
-	return "ExprFunctor"
-}
-
-func (functor *exprFunctor) GetDefinitionContext() kern.ExprContext {
-	return functor.defCtx
-}
-
-func (functor *exprFunctor) InvokeNamed(ctx kern.ExprContext, name string, args map[string]any) (result any, err error) {
-	var missing []string
-	for _, p := range functor.params {
-		if arg, exists := args[p.Name()]; exists {
-			if funcArg, ok := arg.(kern.Functor); ok {
-				paramSpecs := funcArg.GetParams()
-				ctx.RegisterFunc(p.Name(), funcArg, kern.TypeAny, paramSpecs)
-			} else {
-				ctx.UnsafeSetVar(p.Name(), arg)
-			}
-		} else {
-			if missing == nil {
-				missing = make([]string, 0, 1)
-			}
-			missing = append(missing, p.Name())
-			// ctx.UnsafeSetVar(p.Name(), nil)
-		}
-	}
-	if missing != nil {
-		err = kern.ErrMissingParams(name, missing)
-	} else {
-		result, err = functor.expr.Eval(ctx)
-	}
-	return
-}

builtin-base.go

@@ -1,318 +0,0 @@
-// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
-// All rights reserved.
-
-// builtin-base.go
-package expr
-
-import (
-	"fmt"
-	"math"
-	"strconv"
-	"strings"
-
-	"git.portale-stac.it/go-pkg/expr/kern"
-)
-
-const (
-	ParamDenominator = "denominator"
-)
-
-func isNilFunc(ctx kern.ExprContext, name string, args map[string]any) (result any, err error) {
-	result = args[kern.ParamValue] == nil
-	return
-}
-
-func isIntFunc(ctx kern.ExprContext, name string, args map[string]any) (result any, err error) {
-	result = kern.IsInteger(args[kern.ParamValue])
-	return
-}
-
-func isFloatFunc(ctx kern.ExprContext, name string, args map[string]any) (result any, err error) {
-	result = kern.IsFloat(args[kern.ParamValue])
-	return
-}
-
-func isBoolFunc(ctx kern.ExprContext, name string, args map[string]any) (result any, err error) {
-	result = kern.IsBool(args[kern.ParamValue])
-	return
-}
-
-func isStringFunc(ctx kern.ExprContext, name string, args map[string]any) (result any, err error) {
-	result = kern.IsString(args[kern.ParamValue])
-	return
-}
-
-func isFractionFunc(ctx kern.ExprContext, name string, args map[string]any) (result any, err error) {
-	result = kern.IsFraction(args[kern.ParamValue])
-	return
-}
-
-func isRationalFunc(ctx kern.ExprContext, name string, args map[string]any) (result any, err error) {
-	result = kern.IsRational(args[kern.ParamValue])
-	return
-}
-
-func isListFunc(ctx kern.ExprContext, name string, args map[string]any) (result any, err error) {
-	result = kern.IsList(args[kern.ParamValue])
-	return
-}
-
-func isDictionaryFunc(ctx kern.ExprContext, name string, args map[string]any) (result any, err error) {
-	result = kern.IsDict(args[kern.ParamValue])
-	return
-}
-
-func boolFunc(ctx kern.ExprContext, name string, args map[string]any) (result any, err error) {
-	switch v := args[kern.ParamValue].(type) {
-	case int64:
-		result = (v != 0)
-	case *kern.FractionType:
-		result = v.N() != 0
-	case float64:
-		result = v != 0.0
-	case bool:
-		result = v
-	case string:
-		result = len(v) > 0
-	case *kern.ListType:
-		result = len(*v) > 0
-	case *kern.DictType:
-		result = len(*v) > 0
-	default:
-		err = kern.ErrCantConvert(name, v, "bool")
-	}
-	return
-}
-
-func intFunc(ctx kern.ExprContext, name string, args map[string]any) (result any, err error) {
-	switch v := args[kern.ParamValue].(type) {
-	case int64:
-		result = v
-	case float64:
-		result = int64(math.Trunc(v))
-	case bool:
-		if v {
-			result = int64(1)
-		} else {
-			result = int64(0)
-		}
-	case string:
-		var i int
-		if i, err = strconv.Atoi(v); err == nil {
-			result = int64(i)
-		}
-	case *kern.FractionType:
-		result = int64(v.N() / v.D())
-	default:
-		err = kern.ErrCantConvert(name, v, "int")
-	}
-	return
-}
-
-func decFunc(ctx kern.ExprContext, name string, args map[string]any) (result any, err error) {
-	switch v := args[kern.ParamValue].(type) {
-	case int64:
-		result = float64(v)
-	case float64:
-		result = v
-	case bool:
-		if v {
-			result = float64(1)
-		} else {
-			result = float64(0)
-		}
-	case string:
-		var f float64
-		if f, err = strconv.ParseFloat(v, 64); err == nil {
-			result = f
-		}
-	case *kern.FractionType:
-		result = v.ToFloat()
-	default:
-		err = kern.ErrCantConvert(name, v, "float")
-	}
-	return
-}
-
-func stringFunc(ctx kern.ExprContext, name string, args map[string]any) (result any, err error) {
-	switch v := args[kern.ParamValue].(type) {
-	case int64:
-		result = strconv.FormatInt(v, 10)
-	case float64:
-		result = strconv.FormatFloat(v, 'g', -1, 64)
-	case bool:
-		if v {
-			result = "true"
-		} else {
-			result = "false"
-		}
-	case string:
-		result = v
-	case *kern.FractionType:
-		result = v.ToString(0)
-	case kern.Formatter:
-		result = v.ToString(0)
-	case fmt.Stringer:
-		result = v.String()
-	default:
-		err = kern.ErrCantConvert(name, v, "string")
-	}
-	return
-}
-
-func fractFunc(ctx kern.ExprContext, name string, args map[string]any) (result any, err error) {
-	switch v := args[kern.ParamValue].(type) {
-	case int64:
-		var den int64 = 1
-
-		var ok bool
-		if den, ok = args[ParamDenominator].(int64); !ok {
-			err = kern.ErrExpectedGot(name, "integer", args[ParamDenominator])
-		} else if den == 0 {
-			err = kern.ErrFuncDivisionByZero(name)
-		}
-
-		if err == nil {
-			result = kern.NewFraction(v, den)
-		}
-	case float64:
-		result, err = kern.Float64ToFraction(v)
-	case bool:
-		if v {
-			result = kern.NewFraction(1, 1)
-		} else {
-			result = kern.NewFraction(0, 1)
-		}
-	case string:
-		result, err = kern.MakeGeneratingFraction(v)
-	case *kern.FractionType:
-		result = v
-	default:
-		err = kern.ErrCantConvert(name, v, "float")
-	}
-	return
-}
-
-// func iteratorFunc(ctx expr.ExprContext, name string, args []any) (result any, err error) {
-// 	return
-// }
-
-func evalFunc(ctx kern.ExprContext, name string, args map[string]any) (result any, err error) {
-	if source, ok := args[kern.ParamSource].(string); ok {
-		var ast Expr
-
-		parser := NewParser()
-		if ctx == nil {
-			ctx = NewSimpleStoreWithoutGlobalContext()
-		}
-
-		r := strings.NewReader(source)
-		scanner := NewScanner(r, DefaultTranslations())
-
-		if ast, err = parser.Parse(scanner); err == nil {
-			CtrlEnable(ctx, kern.ControlExportAll)
-			result, err = ast.Eval(ctx)
-		}
-	} else {
-		err = kern.ErrWrongParamType(name, kern.ParamSource, kern.TypeString, args[kern.ParamSource])
-	}
-	return
-}
-
-func varFunc(ctx kern.ExprContext, name string, args map[string]any) (result any, err error) {
-	var varName string
-	var ok bool
-
-	if varName, ok = args[kern.ParamName].(string); !ok {
-		return nil, kern.ErrWrongParamType(name, kern.ParamName, kern.TypeString, args[kern.ParamName])
-	}
-
-	if result, ok = args[kern.ParamValue]; ok && result != nil {
-		ctx.GetParent().UnsafeSetVar(varName, result)
-		// } else {
-		// 	err = expr.ErrWrongParamType(name, expr.ParamSource, expr.TypeString, args[expr.ParamSource])
-		// }
-	} else if result, ok = ctx.GetVar(varName); !ok {
-		err = kern.ErrUnknownVar(name, varName)
-	}
-	return
-}
-
-func setFunc(ctx kern.ExprContext, name string, args map[string]any) (result any, err error) {
-	var varName string
-	var ok bool
-
-	if varName, ok = args[kern.ParamName].(string); !ok {
-		return nil, kern.ErrWrongParamType(name, kern.ParamName, kern.TypeString, args[kern.ParamName])
-	}
-
-	if result, ok = args[kern.ParamValue]; ok {
-		ctx.GetParent().UnsafeSetVar(varName, result)
-	} else {
-		err = kern.ErrWrongParamType(name, kern.ParamValue, kern.TypeAny, args[kern.ParamValue])
-	}
-	return
-}
-
-// func unsetFunc(ctx kern.ExprContext, name string, args map[string]any) (result any, err error) {
-// 	var varName string
-// 	var ok bool
-
-// 	if varName, ok = args[kern.ParamName].(string); !ok {
-// 		return nil, kern.ErrWrongParamType(name, kern.ParamName, kern.TypeString, args[kern.ParamName])
-// 	} else {
-// 		ctx.GetParent().DeleteVar(varName)
-// 		result = nil
-// 	}
-// 	return
-// }
-
-//// import
-
-func ImportBuiltinsFuncs(ctx kern.ExprContext) {
-	anyParams := []kern.ExprFuncParam{
-		NewFuncParam(kern.ParamValue),
-	}
-
-	ctx.RegisterFunc("isNil", kern.NewGolangFunctor(isNilFunc), kern.TypeBoolean, anyParams)
-	ctx.RegisterFunc("isInt", kern.NewGolangFunctor(isIntFunc), kern.TypeBoolean, anyParams)
-	ctx.RegisterFunc("isFloat", kern.NewGolangFunctor(isFloatFunc), kern.TypeBoolean, anyParams)
-	ctx.RegisterFunc("isBool", kern.NewGolangFunctor(isBoolFunc), kern.TypeBoolean, anyParams)
-	ctx.RegisterFunc("isString", kern.NewGolangFunctor(isStringFunc), kern.TypeBoolean, anyParams)
-	ctx.RegisterFunc("isFract", kern.NewGolangFunctor(isFractionFunc), kern.TypeBoolean, anyParams)
-	ctx.RegisterFunc("isRational", kern.NewGolangFunctor(isRationalFunc), kern.TypeBoolean, anyParams)
-	ctx.RegisterFunc("isList", kern.NewGolangFunctor(isListFunc), kern.TypeBoolean, anyParams)
-	ctx.RegisterFunc("isDict", kern.NewGolangFunctor(isDictionaryFunc), kern.TypeBoolean, anyParams)
-
-	ctx.RegisterFunc("bool", kern.NewGolangFunctor(boolFunc), kern.TypeBoolean, anyParams)
-	ctx.RegisterFunc("int", kern.NewGolangFunctor(intFunc), kern.TypeInt, anyParams)
-	ctx.RegisterFunc("dec", kern.NewGolangFunctor(decFunc), kern.TypeFloat, anyParams)
-	ctx.RegisterFunc("string", kern.NewGolangFunctor(stringFunc), kern.TypeString, anyParams)
-	ctx.RegisterFunc("fract", kern.NewGolangFunctor(fractFunc), kern.TypeFraction, []kern.ExprFuncParam{
-		NewFuncParam(kern.ParamValue),
-		NewFuncParamFlagDef(ParamDenominator, PfDefault, int64(1)),
-	})
-
-	ctx.RegisterFunc("eval", kern.NewGolangFunctor(evalFunc), kern.TypeAny, []kern.ExprFuncParam{
-		NewFuncParam(kern.ParamSource),
-	})
-
-	ctx.RegisterFunc("var", kern.NewGolangFunctor(varFunc), kern.TypeAny, []kern.ExprFuncParam{
-		NewFuncParam(kern.ParamName),
-		NewFuncParamFlagDef(kern.ParamValue, PfDefault, nil),
-	})
-
-	ctx.RegisterFunc("set", kern.NewGolangFunctor(setFunc), kern.TypeAny, []kern.ExprFuncParam{
-		NewFuncParam(kern.ParamName),
-		NewFuncParam(kern.ParamValue),
-	})
-
-	// ctx.RegisterFunc("unset", kern.NewGolangFunctor(unsetFunc), kern.TypeAny, []kern.ExprFuncParam{
-	// 	NewFuncParam(kern.ParamName),
-	// 	NewFuncParam(kern.ParamValue),
-	// })
-}
-
-func init() {
-	RegisterBuiltinModule("base", ImportBuiltinsFuncs, "Base expression tools like isNil(), int(), etc.")
-}

builtin-fmt.go

@@ -1,59 +0,0 @@
-// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
-// All rights reserved.
-
-// builtin-fmt.go
-package expr
-
-import (
-	"fmt"
-	"io"
-	"os"
-
-	"git.portale-stac.it/go-pkg/expr/kern"
-)
-
-func getStdout(ctx kern.ExprContext) io.Writer {
-	var w io.Writer
-	if wany, exists := ctx.GetVar(kern.ControlStdout); exists && wany != nil {
-		w, _ = wany.(io.Writer)
-	}
-	if w == nil {
-		w = os.Stdout
-	}
-	return w
-}
-
-func printFunc(ctx kern.ExprContext, name string, args map[string]any) (result any, err error) {
-	var n int = 0
-	if v, exists := args[kern.ParamItem]; exists && v != nil {
-		argv := v.([]any)
-		n, err = fmt.Fprint(getStdout(ctx), argv...)
-	}
-	result = int64(n)
-	return
-}
-
-func printLnFunc(ctx kern.ExprContext, name string, args map[string]any) (result any, err error) {
-	var n int = 0
-	if v, exists := args[kern.ParamItem]; exists && v != nil {
-		argv := v.([]any)
-		n, err = fmt.Fprintln(getStdout(ctx), argv...)
-	} else {
-		n, err = fmt.Fprintln(getStdout(ctx))
-	}
-	result = int64(n)
-	return
-}
-
-func ImportFmtFuncs(ctx kern.ExprContext) {
-	ctx.RegisterFunc("print", kern.NewGolangFunctor(printFunc), kern.TypeInt, []kern.ExprFuncParam{
-		NewFuncParamFlag(kern.ParamItem, PfRepeat),
-	})
-	ctx.RegisterFunc("println", kern.NewGolangFunctor(printLnFunc), kern.TypeInt, []kern.ExprFuncParam{
-		NewFuncParamFlag(kern.ParamItem, PfRepeat),
-	})
-}
-
-func init() {
-	RegisterBuiltinModule("fmt", ImportFmtFuncs, "String and console formatting functions")
-}

builtin-import.go

@@ -1,80 +0,0 @@
-// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
-// All rights reserved.
-
-// builtin-import.go
-package expr
-
-import (
-	"io"
-	"os"
-
-	"git.portale-stac.it/go-pkg/expr/kern"
-)
-
-func importFunc(ctx kern.ExprContext, name string, args map[string]any) (result any, err error) {
-	return importGeneral(ctx, name, args)
-}
-
-func importAllFunc(ctx kern.ExprContext, name string, args map[string]any) (result any, err error) {
-	CtrlEnable(ctx, kern.ControlExportAll)
-	return importGeneral(ctx, name, args)
-}
-
-func importGeneral(ctx kern.ExprContext, name string, args map[string]any) (result any, err error) {
-	dirList := buildSearchDirList(ctx, "sources", ENV_EXPR_SOURCE_PATH)
-	if v, exists := args[kern.ParamFilepath]; exists && v != nil {
-		argv := v.([]any)
-		result, err = doImport(ctx, name, dirList, NewArrayIterator(argv))
-	}
-	return
-}
-
-func doImport(ctx kern.ExprContext, name string, dirList []string, it kern.Iterator) (result any, err error) {
-	var v any
-	var sourceFilepath string
-
-	for v, err = it.Next(); err == nil; v, err = it.Next() {
-		if err = checkStringParamExpected(name, v, int(it.Index())); err != nil {
-			break
-		}
-		if sourceFilepath, err = makeFilepath(v.(string), dirList); err != nil {
-			break
-		}
-		var file *os.File
-		if file, err = os.Open(sourceFilepath); err == nil {
-			defer file.Close()
-			var expr *ast
-			scanner := NewScanner(file, DefaultTranslations())
-			parser := NewParser()
-			if expr, err = parser.parseGeneral(scanner, allowMultiExpr|allowVarRef, SymEos); err == nil {
-				result, err = expr.Eval(ctx)
-			}
-			if err != nil {
-				break
-			}
-		} else {
-			break
-		}
-	}
-	if err != nil {
-		if err == io.EOF {
-			err = nil
-		} else {
-			result = nil
-		}
-	}
-	return
-}
-
-func ImportImportFuncs(ctx kern.ExprContext) {
-	ctx.RegisterFunc("import", kern.NewGolangFunctor(importFunc), kern.TypeAny, []kern.ExprFuncParam{
-		NewFuncParamFlag(kern.ParamFilepath, PfRepeat),
-	})
-	ctx.RegisterFunc("importAll", kern.NewGolangFunctor(importAllFunc), kern.TypeAny, []kern.ExprFuncParam{
-		NewFuncParamFlag(kern.ParamFilepath, PfRepeat),
-	})
-}
-
-func init() {
-	RegisterBuiltinModule("import", ImportImportFuncs, "Functions import() and include()")
-}

builtin-iterator.go

@@ -1,105 +0,0 @@
-// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
-// All rights reserved.
-
-// builtin-iterator.go
-package expr
-
-import (
-	"fmt"
-	"io"
-
-	"git.portale-stac.it/go-pkg/expr/kern"
-)
-
-const (
-	iterParamOperator = "operator"
-	iterParamVars     = "vars"
-	iterVarStatus     = "status"
-)
-
-func parseRunArgs(localCtx kern.ExprContext, args map[string]any) (it kern.Iterator, op kern.Functor, err error) {
-	var ok bool
-
-	if it, ok = args[kern.ParamIterator].(kern.Iterator); !ok {
-		err = fmt.Errorf("paramter %q must be an iterator, passed %v [%s]", kern.ParamIterator, args[kern.ParamIterator], kern.TypeName(args[kern.ParamIterator]))
-		return
-	}
-
-	if args[iterParamOperator] != nil {
-		if op, ok = args[iterParamOperator].(kern.Functor); !ok || op == nil {
-			err = fmt.Errorf("paramter %q must be a function, passed %v [%s]", iterParamOperator, args[iterParamOperator], kern.TypeName(args[iterParamOperator]))
-			return
-		}
-	}
-
-	var vars *kern.DictType
-	if vars, ok = args[iterParamVars].(*kern.DictType); !ok && args[iterParamVars] != nil {
-		err = fmt.Errorf("paramter %q must be a dictionary, passed %v [%s]", iterParamVars, args[iterParamVars], kern.TypeName(args[iterParamVars]))
-		return
-	}
-
-	if vars != nil {
-		for key, value := range *vars {
-			var varName string
-			if varName, ok = key.(string); ok {
-				localCtx.UnsafeSetVar(varName, value)
-			}
-		}
-	}
-
-	return
-}
-
-func runFunc(ctx kern.ExprContext, name string, args map[string]any) (result any, err error) {
-	var it kern.Iterator
-	var ok bool
-	var op kern.Functor
-	var v any
-	// var usingDefaultOp = false
-	var params map[string]any
-	var item any
-
-	localCtx := ctx.Clone()
-	localCtx.UnsafeSetVar(iterVarStatus, nil)
-
-	if it, op, err = parseRunArgs(localCtx, args); err != nil {
-		return
-	}
-
-	for item, err = it.Next(); err == nil; item, err = it.Next() {
-		if op != nil {
-			params = map[string]any{kern.ParamIndex: it.Index(), kern.ParamItem: item}
-			if v, err = op.InvokeNamed(localCtx, iterParamOperator, params); err != nil {
-				break
-			} else {
-				var success bool
-				if success, ok = kern.ToBool(v); !success || !ok {
-					break
-				}
-			}
-		}
-	}
-
-	if err == io.EOF {
-		err = nil
-	}
-	if err == nil {
-		if op == nil {
-			ctx.UnsafeSetVar(iterVarStatus, it.Count())
-		}
-		result, _ = localCtx.GetVar(iterVarStatus)
-	}
-	return
-}
-
-func ImportIterFuncs(ctx kern.ExprContext) {
-	ctx.RegisterFunc("run", kern.NewGolangFunctor(runFunc), kern.TypeAny, []kern.ExprFuncParam{
-		NewFuncParam(kern.ParamIterator),
-		NewFuncParamFlag(iterParamOperator, PfOptional),
-		NewFuncParamFlag(iterParamVars, PfOptional),
-	})
-}
-
-func init() {
-	RegisterBuiltinModule("iterator", ImportIterFuncs, "Iterator helper functions")
-}

builtin-math-arith.go

@@ -1,185 +0,0 @@
-// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
-// All rights reserved.
-
-// builtin-math-arith.go
-package expr
-
-import (
-	"fmt"
-	"io"
-
-	"git.portale-stac.it/go-pkg/expr/kern"
-)
-
-func checkNumberParamExpected(funcName string, paramValue any, paramPos, level, subPos int) (err error) {
-	if !(kern.IsNumber(paramValue) || kern.IsFraction(paramValue)) /*|| isList(paramValue)*/ {
-		err = fmt.Errorf("%s(): param nr %d (%d in %d) has wrong type %T, number expected",
-			funcName, paramPos+1, subPos+1, level, paramValue)
-	}
-	return
-}
-
-func doAdd(ctx kern.ExprContext, name string, it kern.Iterator, count, level int) (result any, err error) {
-	var sumAsFloat, sumAsFract bool
-	var floatSum float64 = 0.0
-	var intSum int64 = 0
-	var fractSum *kern.FractionType
-	var v any
-
-	level++
-
-	for v, err = it.Next(); err == nil; v, err = it.Next() {
-		if list, ok := v.(*kern.ListType); ok {
-			v = NewListIterator(list, nil)
-		}
-		if subIter, ok := v.(kern.Iterator); ok {
-			if v, err = doAdd(ctx, name, subIter, count, level); err != nil {
-				break
-			}
-			if extIter, ok := v.(kern.ExtIterator); ok && extIter.HasOperation(kern.CleanName) {
-				if _, err = extIter.CallOperation(kern.CleanName, nil); err != nil {
-					return
-				}
-			}
-		} else if err = checkNumberParamExpected(name, v, count, level, int(it.Index())); err != nil {
-			break
-		}
-		count++
-
-		if !sumAsFloat {
-			if kern.IsFloat(v) {
-				sumAsFloat = true
-				if sumAsFract {
-					floatSum = fractSum.ToFloat()
-				} else {
-					floatSum = float64(intSum)
-				}
-			} else if !sumAsFract && kern.IsFraction(v) {
-				fractSum = kern.NewFraction(intSum, 1)
-				sumAsFract = true
-			}
-		}
-
-		if sumAsFloat {
-			floatSum += kern.NumAsFloat(v)
-		} else if sumAsFract {
-			var item *kern.FractionType
-			var ok bool
-			if item, ok = v.(*kern.FractionType); !ok {
-				iv, _ := v.(int64)
-				item = kern.NewFraction(iv, 1)
-			}
-			fractSum = kern.SumFract(fractSum, item)
-		} else {
-			iv, _ := v.(int64)
-			intSum += iv
-		}
-	}
-	if err == nil || err == io.EOF {
-		err = nil
-		if sumAsFloat {
-			result = floatSum
-		} else if sumAsFract {
-			result = fractSum
-		} else {
-			result = intSum
-		}
-	}
-	return
-}
-
-func addFunc(ctx kern.ExprContext, name string, args map[string]any) (result any, err error) {
-	argv := args[kern.ParamValue].([]any)
-	result, err = doAdd(ctx, name, NewArrayIterator(argv), 0, -1)
-	return
-}
-
-func doMul(ctx kern.ExprContext, name string, it kern.Iterator, count, level int) (result any, err error) {
-	var mulAsFloat, mulAsFract bool
-	var floatProd float64 = 1.0
-	var intProd int64 = 1
-	var fractProd *kern.FractionType
-	var v any
-
-	level++
-	for v, err = it.Next(); err == nil; v, err = it.Next() {
-		if list, ok := v.(*kern.ListType); ok {
-			v = NewListIterator(list, nil)
-		}
-		if subIter, ok := v.(kern.Iterator); ok {
-			if v, err = doMul(ctx, name, subIter, count, level); err != nil {
-				break
-			}
-			if extIter, ok := v.(kern.ExtIterator); ok && extIter.HasOperation(kern.CleanName) {
-				if _, err = extIter.CallOperation(kern.CleanName, nil); err != nil {
-					return
-				}
-			}
-		} else {
-			if err = checkNumberParamExpected(name, v, count, level, int(it.Index())); err != nil {
-				break
-			}
-		}
-		count++
-
-		if !mulAsFloat {
-			if kern.IsFloat(v) {
-				mulAsFloat = true
-				if mulAsFract {
-					floatProd = fractProd.ToFloat()
-				} else {
-					floatProd = float64(intProd)
-				}
-			} else if !mulAsFract && kern.IsFraction(v) {
-				fractProd = kern.NewFraction(intProd, 1)
-				mulAsFract = true
-			}
-		}
-
-		if mulAsFloat {
-			floatProd *= kern.NumAsFloat(v)
-		} else if mulAsFract {
-			var item *kern.FractionType
-			var ok bool
-			if item, ok = v.(*kern.FractionType); !ok {
-				iv, _ := v.(int64)
-				item = kern.NewFraction(iv, 1)
-			}
-			fractProd = kern.MulFract(fractProd, item)
-		} else {
-			iv, _ := v.(int64)
-			intProd *= iv
-		}
-	}
-	if err == nil || err == io.EOF {
-		err = nil
-		if mulAsFloat {
-			result = floatProd
-		} else if mulAsFract {
-			result = fractProd
-		} else {
-			result = intProd
-		}
-	}
-	return
-}
-
-func mulFunc(ctx kern.ExprContext, name string, args map[string]any) (result any, err error) {
-	argv := args[kern.ParamValue].([]any)
-	result, err = doMul(ctx, name, NewArrayIterator(argv), 0, -1)
-	return
-}
-
-func ImportMathFuncs(ctx kern.ExprContext) {
-	ctx.RegisterFunc("add", kern.NewGolangFunctor(addFunc), kern.TypeNumber, []kern.ExprFuncParam{
-		NewFuncParamFlagDef(kern.ParamValue, PfDefault|PfRepeat, int64(0)),
-	})
-
-	ctx.RegisterFunc("mul", kern.NewGolangFunctor(mulFunc), kern.TypeNumber, []kern.ExprFuncParam{
-		NewFuncParamFlagDef(kern.ParamValue, PfDefault|PfRepeat, int64(1)),
-	})
-}
-
-func init() {
-	RegisterBuiltinModule("math.arith", ImportMathFuncs, "Functions add() and mul()")
-}

builtin-os-file-iter.go

@@ -1,151 +0,0 @@
-// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
-// All rights reserved.
-
-// builtin-os-file.go
-package expr
-
-import (
-	"fmt"
-	"io"
-	"slices"
-
-	"git.portale-stac.it/go-pkg/expr/kern"
-)
-
-const paramHandleOrPath = "handle-or-path"
-const fileReadTextIteratorType = "fileReadTextIterator"
-
-type fileReadTextIterator struct {
-	osReader  *osReader
-	index     int64
-	count     int64
-	line      string
-	autoClose bool
-}
-
-func newReadTextIterator(r *osReader, autoClose bool) *fileReadTextIterator {
-	return &fileReadTextIterator{osReader: r, index: -1, autoClose: autoClose}
-}
-
-func (it *fileReadTextIterator) TypeName() string {
-	return fileReadTextIteratorType
-}
-
-func (it *fileReadTextIterator) String() string {
-	if it.osReader != nil && it.osReader.fh != nil {
-		return fmt.Sprintf("$(%s@%q)", fileReadTextIteratorType, it.osReader.fh.Name())
-	}
-	return fmt.Sprintf("$(%s@<nil>)", fileReadTextIteratorType)
-}
-
-func (it *fileReadTextIterator) Count() int64 {
-	return it.count
-}
-
-func (it *fileReadTextIterator) Next() (item any, err error) { // must return io.EOF after the last item
-	if it.osReader.fh != nil {
-		if it.line, err = it.osReader.reader.ReadString('\n'); err == nil {
-			it.index++
-			it.count++
-			item = it.line[0 : len(it.line)-1]
-		} else if it.autoClose {
-			it.Clean()
-		}
-	}
-	return
-}
-
-func (it *fileReadTextIterator) Current() (item any, err error) {
-	if len(it.line) > 0 {
-		item = it.line[0 : len(it.line)-1]
-	}
-	return
-}
-
-func (it *fileReadTextIterator) Index() int64 {
-	return it.index
-}
-
-func (it *fileReadTextIterator) Reset() (err error) {
-	if _, err = it.osReader.fh.Seek(0, io.SeekStart); err == nil {
-		it.index = -1
-		it.count = 0
-		it.line = ""
-	}
-	return
-}
-
-func (it *fileReadTextIterator) HasOperation(name string) bool {
-	return slices.Contains([]string{kern.NextName, kern.ResetName, kern.IndexName, kern.CountName, kern.CurrentName, kern.CleanName}, name)
-}
-
-func (it *fileReadTextIterator) Clean() (err error) {
-	if it.osReader.fh != nil {
-		if err = it.osReader.fh.Close(); err == nil {
-			it.osReader = nil
-		}
-	}
-	return nil
-}
-
-func (it *fileReadTextIterator) CallOperation(name string, args map[string]any) (v any, err error) {
-	switch name {
-	case kern.NextName:
-		v, err = it.Next()
-	case kern.ResetName:
-		err = it.Reset()
-	case kern.CleanName:
-		err = it.Clean()
-	case kern.IndexName:
-		v = int64(it.Index())
-	case kern.CurrentName:
-		v, err = it.Current()
-	case kern.CountName:
-		v = it.count
-	default:
-		err = kern.ErrNoOperation(name)
-	}
-	return
-}
-
-func fileReadIteratorFunc(ctx kern.ExprContext, name string, args map[string]any) (result any, err error) {
-	var handle *osReader
-	var invalidFileHandle any
-	var ok, autoClose bool
-
-	result = nil
-	if handle, ok = args[paramHandleOrPath].(*osReader); !ok {
-		if fileName, ok := args[paramHandleOrPath].(string); ok && len(fileName) > 0 {
-			var handleAny any
-			if handleAny, err = openFileFunc(ctx, name, map[string]any{kern.ParamFilepath: fileName}); err != nil {
-				return
-			}
-			if handleAny != nil {
-				handle = handleAny.(*osReader)
-				autoClose = true
-			}
-		} else {
-			invalidFileHandle = args[paramHandleOrPath]
-		}
-	}
-
-	if handle != nil {
-		result = newReadTextIterator(handle, autoClose)
-
-	}
-
-	if err == nil && (handle == nil || invalidFileHandle != nil) {
-		err = errInvalidFileHandle(name, invalidFileHandle)
-	}
-	return
-}
-
-// func ImportOsIterFuncs(ctx ExprContext) {
-// 	ctx.RegisterFunc("fileReadIterator", NewGolangFunctor(fileReadIteratorFunc), TypeIterator, []ExprFuncParam{
-// 		NewFuncParam(paramHandleOrPath),
-// 	})
-// }
-
-// func init() {
-// 	RegisterBuiltinModule("os.file", ImportOsIterFuncs, "Operating system file iterator functions")
-// }

builtin-os-file.go

@@ -1,263 +0,0 @@
-// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
-// All rights reserved.
-
-// builtin-os-file.go
-package expr
-
-import (
-	"bufio"
-	"fmt"
-	"io"
-	"os"
-
-	"git.portale-stac.it/go-pkg/expr/kern"
-)
-
-const (
-	osLimitCh = "limitCh"
-)
-
-type osHandle interface {
-	getFile() *os.File
-}
-
-type osWriter struct {
-	fh     *os.File
-	writer *bufio.Writer
-}
-
-func (h *osWriter) TypeName() string {
-	return "osWriter"
-}
-
-func (h *osWriter) String() string {
-	return "writer"
-}
-
-func (h *osWriter) getFile() *os.File {
-	return h.fh
-}
-
-type osReader struct {
-	fh     *os.File
-	reader *bufio.Reader
-}
-
-func (h *osReader) TypeName() string {
-	return "osReader"
-}
-
-func (h *osReader) String() string {
-	return "reader"
-}
-
-func (h *osReader) getFile() *os.File {
-	return h.fh
-}
-
-func errMissingFilePath(funcName string) error {
-	return fmt.Errorf("%s(): missing or invalid file path", funcName)
-}
-
-func errInvalidFileHandle(funcName string, v any) error {
-	if v != nil {
-		return fmt.Errorf("%s(): invalid file handle %v [%T]", funcName, v, v)
-	} else {
-		return fmt.Errorf("%s(): invalid file handle", funcName)
-	}
-}
-
-func createFileFunc(ctx kern.ExprContext, name string, args map[string]any) (result any, err error) {
-	if filePath, ok := args[kern.ParamFilepath].(string); ok && len(filePath) > 0 {
-		var fh *os.File
-		if fh, err = os.Create(filePath); err == nil {
-			result = &osWriter{fh: fh, writer: bufio.NewWriter(fh)}
-		}
-	} else {
-		err = errMissingFilePath(name)
-	}
-	return
-}
-
-func openFileFunc(ctx kern.ExprContext, name string, args map[string]any) (result any, err error) {
-	if filePath, ok := args[kern.ParamFilepath].(string); ok && len(filePath) > 0 {
-		var fh *os.File
-		if fh, err = os.Open(filePath); err == nil {
-			result = &osReader{fh: fh, reader: bufio.NewReader(fh)}
-		}
-	} else {
-		err = errMissingFilePath(name)
-	}
-	return
-}
-
-func appendFileFunc(ctx kern.ExprContext, name string, args map[string]any) (result any, err error) {
-	if filePath, ok := args[kern.ParamFilepath].(string); ok && len(filePath) > 0 {
-		var fh *os.File
-		if fh, err = os.OpenFile(filePath, os.O_APPEND|os.O_WRONLY|os.O_CREATE, 0660); err == nil {
-			result = &osWriter{fh: fh, writer: bufio.NewWriter(fh)}
-		}
-	} else {
-		err = errMissingFilePath(name)
-	}
-	return
-}
-
-func closeFileFunc(ctx kern.ExprContext, name string, args map[string]any) (result any, err error) {
-	var handle osHandle
-	var invalidFileHandle any
-	var ok bool
-
-	if handle, ok = args[kern.ParamHandle].(osHandle); !ok {
-		invalidFileHandle = args[kern.ParamHandle]
-	}
-
-	if handle != nil {
-		if fh := handle.getFile(); fh != nil {
-			if w, ok := handle.(*osWriter); ok {
-				err = w.writer.Flush()
-			}
-
-			if err == nil {
-				err = fh.Close()
-			}
-		}
-	}
-	if err == nil && (handle == nil || invalidFileHandle != nil) {
-		err = errInvalidFileHandle(name, handle)
-	}
-	result = err == nil
-	return
-}
-
-func fileWriteTextFunc(ctx kern.ExprContext, name string, args map[string]any) (result any, err error) {
-	var handle osHandle
-	var invalidFileHandle any
-	var ok bool
-
-	if handle, ok = args[kern.ParamHandle].(osHandle); !ok {
-		invalidFileHandle = args[kern.ParamHandle]
-	}
-
-	if handle != nil {
-		if w, ok := handle.(*osWriter); ok {
-			if v, exists := args[kern.ParamItem]; exists {
-				argv := v.([]any)
-				result, err = fmt.Fprint(w.writer, argv...)
-			}
-		} else {
-			invalidFileHandle = handle
-		}
-	}
-
-	if err == nil && (handle == nil || invalidFileHandle != nil) {
-		err = errInvalidFileHandle(name, invalidFileHandle)
-	}
-	return
-}
-
-func fileReadTextFunc(ctx kern.ExprContext, name string, args map[string]any) (result any, err error) {
-	var handle osHandle
-	var invalidFileHandle any
-	var ok bool
-
-	result = nil
-	if handle, ok = args[kern.ParamHandle].(osHandle); !ok || args[kern.ParamHandle] == nil {
-		invalidFileHandle = args[kern.ParamHandle]
-	}
-
-	if handle != nil {
-		if r, ok := handle.(*osReader); ok {
-			var limit byte = '\n'
-			var v string
-			if s, ok := args[osLimitCh].(string); ok && len(s) > 0 {
-				limit = s[0]
-			}
-
-			v, err = r.reader.ReadString(limit)
-			if err == io.EOF {
-				err = nil
-			}
-			if len(v) > 0 {
-				if v[len(v)-1] == limit {
-					result = v[0 : len(v)-1]
-				} else {
-					result = v
-				}
-			}
-		} else {
-			invalidFileHandle = handle
-		}
-	}
-
-	if err == nil && (handle == nil || invalidFileHandle != nil) {
-		err = errInvalidFileHandle(name, invalidFileHandle)
-	}
-	return
-}
-
-func fileReadTextAllFunc(ctx kern.ExprContext, name string, args map[string]any) (result any, err error) {
-	var handle osHandle
-	var invalidFileHandle any
-	var ok bool
-
-	result = nil
-	if handle, ok = args[kern.ParamHandle].(osHandle); !ok || args[kern.ParamHandle] == nil {
-		invalidFileHandle = args[kern.ParamHandle]
-	}
-
-	if handle != nil {
-		if r, ok := handle.(*osReader); ok {
-			var b []byte
-			b, err = io.ReadAll(r.reader)
-			result = string(b)
-		} else {
-			invalidFileHandle = handle
-		}
-	}
-
-	if err == nil && (handle == nil || invalidFileHandle != nil) {
-		err = errInvalidFileHandle(name, invalidFileHandle)
-	}
-	return
-}
-
-func ImportOsFuncs(ctx kern.ExprContext) {
-	ctx.RegisterFunc("fileOpen", kern.NewGolangFunctor(openFileFunc), kern.TypeFileHandle, []kern.ExprFuncParam{
-		NewFuncParam(kern.ParamFilepath),
-	})
-
-	ctx.RegisterFunc("fileAppend", kern.NewGolangFunctor(appendFileFunc), kern.TypeFileHandle, []kern.ExprFuncParam{
-		NewFuncParam(kern.ParamFilepath),
-	})
-
-	ctx.RegisterFunc("fileCreate", kern.NewGolangFunctor(createFileFunc), kern.TypeFileHandle, []kern.ExprFuncParam{
-		NewFuncParam(kern.ParamFilepath),
-	})
-
-	ctx.RegisterFunc("fileClose", kern.NewGolangFunctor(closeFileFunc), kern.TypeBoolean, []kern.ExprFuncParam{
-		NewFuncParam(kern.ParamHandle),
-	})
-
-	ctx.RegisterFunc("fileWriteText", kern.NewGolangFunctor(fileWriteTextFunc), kern.TypeInt, []kern.ExprFuncParam{
-		NewFuncParam(kern.ParamHandle),
-		NewFuncParamFlagDef(kern.ParamItem, PfDefault|PfRepeat, ""),
-	})
-
-	ctx.RegisterFunc("fileReadText", kern.NewGolangFunctor(fileReadTextFunc), kern.TypeString, []kern.ExprFuncParam{
-		NewFuncParam(kern.ParamHandle),
-		NewFuncParamFlagDef(osLimitCh, PfDefault, "\n"),
-	})
-
-	ctx.RegisterFunc("fileReadTextAll", kern.NewGolangFunctor(fileReadTextAllFunc), kern.TypeString, []kern.ExprFuncParam{
-		NewFuncParam(kern.ParamHandle),
-	})
-
-	ctx.RegisterFunc("fileReadIterator", kern.NewGolangFunctor(fileReadIteratorFunc), kern.TypeIterator, []kern.ExprFuncParam{
-		NewFuncParam(paramHandleOrPath),
-	})
-}
-
-func init() {
-	RegisterBuiltinModule("os.file", ImportOsFuncs, "Operating system file functions")
-}

builtin-string.go

@@ -1,273 +0,0 @@
-// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
-// All rights reserved.
-
-// builtin-string.go
-package expr
-
-import (
-	"fmt"
-	"io"
-	"strings"
-
-	"git.portale-stac.it/go-pkg/expr/kern"
-)
-
-const (
-	strParamOther = "other"
-)
-
-// --- Start of function definitions
-func doJoinStr(funcName string, sep string, it kern.Iterator) (result any, err error) {
-	var sb strings.Builder
-	var v any
-	for v, err = it.Next(); err == nil; v, err = it.Next() {
-		if it.Index() > 0 {
-			sb.WriteString(sep)
-		}
-		if s, ok := v.(string); ok {
-			sb.WriteString(s)
-		} else {
-			err = kern.ErrExpectedGot(funcName, kern.TypeString, v)
-			return
-		}
-	}
-	if err == io.EOF {
-		err = nil
-		result = sb.String()
-	}
-	return
-}
-
-func joinStrFunc(ctx kern.ExprContext, name string, args map[string]any) (result any, err error) {
-	if sep, ok := args[kern.ParamSeparator].(string); ok {
-		if v, exists := args[kern.ParamItem]; exists {
-			argv := v.([]any)
-			if len(argv) == 1 {
-				if ls, ok := argv[0].(*kern.ListType); ok {
-					result, err = doJoinStr(name, sep, NewListIterator(ls, nil))
-				} else if it, ok := argv[0].(kern.Iterator); ok {
-					result, err = doJoinStr(name, sep, it)
-				} else if s, ok := argv[0].(string); ok {
-					result = s
-				} else {
-					err = kern.ErrInvalidParameterValue(name, kern.ParamItem, v)
-				}
-			} else {
-				result, err = doJoinStr(name, sep, NewArrayIterator(argv))
-			}
-		}
-	} else {
-		err = kern.ErrWrongParamType(name, kern.ParamSeparator, kern.TypeString, args[kern.ParamSeparator])
-	}
-	return
-}
-
-func subStrFunc(ctx kern.ExprContext, name string, args map[string]any) (result any, err error) {
-	var start = 0
-	var count = -1
-	var source string
-	var ok bool
-
-	if source, ok = args[kern.ParamSource].(string); !ok {
-		return nil, kern.ErrWrongParamType(name, kern.ParamSource, kern.TypeString, args[kern.ParamSource])
-	}
-
-	if start, err = kern.ToGoInt(args[kern.ParamStart], name+"()"); err != nil {
-		return
-	}
-
-	if count, err = kern.ToGoInt(args[kern.ParamCount], name+"()"); err != nil {
-		return
-	}
-
-	if start < 0 {
-		start = len(source) + start
-	}
-
-	if count < 0 {
-		count = len(source) - start
-	}
-	end := min(start+count, len(source))
-	result = source[start:end]
-	return
-}
-
-func trimStrFunc(ctx kern.ExprContext, name string, args map[string]any) (result any, err error) {
-	var source string
-	var ok bool
-
-	if source, ok = args[kern.ParamSource].(string); !ok {
-		return nil, kern.ErrWrongParamType(name, kern.ParamSource, kern.TypeString, args[kern.ParamSource])
-	}
-	result = strings.TrimSpace(source)
-	return
-}
-
-func startsWithStrFunc(ctx kern.ExprContext, name string, args map[string]any) (result any, err error) {
-	var source, prefix string
-	var ok bool
-
-	result = false
-
-	if source, ok = args[kern.ParamSource].(string); !ok {
-		return result, kern.ErrWrongParamType(name, kern.ParamSource, kern.TypeString, args[kern.ParamSource])
-	}
-
-	if prefix, ok = args[kern.ParamPrefix].(string); !ok {
-		return result, kern.ErrWrongParamType(name, kern.ParamPrefix, kern.TypeString, args[kern.ParamPrefix])
-	}
-	if strings.HasPrefix(source, prefix) {
-		result = true
-	} else if v, exists := args[strParamOther]; exists {
-		argv := v.([]any)
-		for i, targetSpec := range argv {
-			if target, ok := targetSpec.(string); ok {
-				if strings.HasPrefix(source, target) {
-					result = true
-					break
-				}
-			} else {
-				err = fmt.Errorf("target item nr %d is %s, string expected", i+1, kern.TypeName(targetSpec))
-				break
-			}
-		}
-	}
-	return
-}
-
-func endsWithStrFunc(ctx kern.ExprContext, name string, args map[string]any) (result any, err error) {
-	var source, suffix string
-	var ok bool
-
-	result = false
-
-	if source, ok = args[kern.ParamSource].(string); !ok {
-		return result, kern.ErrWrongParamType(name, kern.ParamSource, kern.TypeString, args[kern.ParamSource])
-	}
-
-	if suffix, ok = args[kern.ParamSuffix].(string); !ok {
-		return result, kern.ErrWrongParamType(name, kern.ParamSuffix, kern.TypeString, args[kern.ParamSuffix])
-	}
-	if strings.HasPrefix(source, suffix) {
-		result = true
-	} else if v, exists := args[strParamOther]; exists {
-		argv := v.([]any)
-		for i, targetSpec := range argv {
-			if target, ok := targetSpec.(string); ok {
-				if strings.HasSuffix(source, target) {
-					result = true
-					break
-				}
-			} else {
-				err = fmt.Errorf("target item nr %d is %s, string expected", i+1, kern.TypeName(targetSpec))
-				break
-			}
-		}
-	}
-	return
-}
-
-func splitStrFunc(ctx kern.ExprContext, name string, args map[string]any) (result any, err error) {
-	var source, sep string
-	var count int = -1
-	var parts []string
-	var ok bool
-
-	if source, ok = args[kern.ParamSource].(string); !ok {
-		return result, kern.ErrWrongParamType(name, kern.ParamSource, kern.TypeString, args[kern.ParamSource])
-	}
-
-	if sep, ok = args[kern.ParamSeparator].(string); !ok {
-		return nil, fmt.Errorf("separator param must be string, got %s (%v)", kern.TypeName(args[kern.ParamSeparator]), args[kern.ParamSeparator])
-	}
-
-	if count64, ok := args[kern.ParamCount].(int64); ok { // TODO replace type assertion with toInt()
-		count = int(count64)
-	} else {
-		return nil, fmt.Errorf("part count must be integer, got %s (%v)", kern.TypeName(args[kern.ParamCount]), args[kern.ParamCount])
-	}
-
-	if count > 0 {
-		parts = strings.SplitN(source, sep, count)
-	} else if count < 0 {
-		parts = strings.Split(source, sep)
-	} else {
-		parts = []string{}
-	}
-	list := make(kern.ListType, len(parts))
-	for i, part := range parts {
-		list[i] = part
-	}
-	result = &list
-	return
-}
-
-func upperStrFunc(ctx kern.ExprContext, name string, args map[string]any) (result any, err error) {
-	if source, ok := args[kern.ParamSource].(string); ok {
-		result = strings.ToUpper(source)
-	} else {
-		err = kern.ErrWrongParamType(name, kern.ParamSource, kern.TypeString, args[kern.ParamSource])
-	}
-	return
-}
-
-func lowerStrFunc(ctx kern.ExprContext, name string, args map[string]any) (result any, err error) {
-	if source, ok := args[kern.ParamSource].(string); ok {
-		result = strings.ToLower(source)
-	} else {
-		err = kern.ErrWrongParamType(name, kern.ParamSource, kern.TypeString, args[kern.ParamSource])
-	}
-	return
-}
-
-// --- End of function definitions
-
-// Import above functions in the context
-func ImportStringFuncs(ctx kern.ExprContext) {
-	ctx.RegisterFunc("strJoin", kern.NewGolangFunctor(joinStrFunc), kern.TypeString, []kern.ExprFuncParam{
-		NewFuncParam(kern.ParamSeparator),
-		NewFuncParamFlag(kern.ParamItem, PfRepeat),
-	})
-
-	ctx.RegisterFunc("strSub", kern.NewGolangFunctor(subStrFunc), kern.TypeString, []kern.ExprFuncParam{
-		NewFuncParam(kern.ParamSource),
-		NewFuncParamFlagDef(kern.ParamStart, PfDefault, int64(0)),
-		NewFuncParamFlagDef(kern.ParamCount, PfDefault, int64(-1)),
-	})
-
-	ctx.RegisterFunc("strSplit", kern.NewGolangFunctor(splitStrFunc), "list of "+kern.TypeString, []kern.ExprFuncParam{
-		NewFuncParam(kern.ParamSource),
-		NewFuncParamFlagDef(kern.ParamSeparator, PfDefault, ""),
-		NewFuncParamFlagDef(kern.ParamCount, PfDefault, int64(-1)),
-	})
-
-	ctx.RegisterFunc("strTrim", kern.NewGolangFunctor(trimStrFunc), kern.TypeString, []kern.ExprFuncParam{
-		NewFuncParam(kern.ParamSource),
-	})
-
-	ctx.RegisterFunc("strStartsWith", kern.NewGolangFunctor(startsWithStrFunc), kern.TypeBoolean, []kern.ExprFuncParam{
-		NewFuncParam(kern.ParamSource),
-		NewFuncParam(kern.ParamPrefix),
-		NewFuncParamFlag(strParamOther, PfRepeat),
-	})
-
-	ctx.RegisterFunc("strEndsWith", kern.NewGolangFunctor(endsWithStrFunc), kern.TypeBoolean, []kern.ExprFuncParam{
-		NewFuncParam(kern.ParamSource),
-		NewFuncParam(kern.ParamSuffix),
-		NewFuncParamFlag(strParamOther, PfRepeat),
-	})
-
-	ctx.RegisterFunc("strUpper", kern.NewGolangFunctor(upperStrFunc), kern.TypeString, []kern.ExprFuncParam{
-		NewFuncParam(kern.ParamSource),
-	})
-
-	ctx.RegisterFunc("strLower", kern.NewGolangFunctor(lowerStrFunc), kern.TypeString, []kern.ExprFuncParam{
-		NewFuncParam(kern.ParamSource),
-	})
-}
-
-// Register the import function in the import-register.
-// That will allow to import all function of this module by the "builtin" operator."
-func init() {
-	RegisterBuiltinModule("string", ImportStringFuncs, "string utilities")
-}

builtins-register.go

@@ -1,50 +0,0 @@
-// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
-// All rights reserved.
-
-// builtins-register.go
-package expr
-
-import (
-	"fmt"
-
-	"git.portale-stac.it/go-pkg/expr/kern"
-)
-
-type builtinModule struct {
-	importFunc  func(kern.ExprContext)
-	description string
-	imported    bool
-}
-
-func newBuiltinModule(importFunc func(kern.ExprContext), description string) *builtinModule {
-	return &builtinModule{importFunc, description, false}
-}
-
-var builtinModuleRegister map[string]*builtinModule
-
-func RegisterBuiltinModule(name string, importFunc func(kern.ExprContext), description string) {
-	if builtinModuleRegister == nil {
-		builtinModuleRegister = make(map[string]*builtinModule)
-	}
-	if _, exists := builtinModuleRegister[name]; exists {
-		panic(fmt.Errorf("module %q already registered", name))
-	}
-	builtinModuleRegister[name] = newBuiltinModule(importFunc, description)
-}
-
-func IterateBuiltinModules(op func(name, description string, imported bool) bool) {
-	if op != nil {
-		for name, mod := range builtinModuleRegister {
-			if !op(name, mod.description, mod.imported) {
-				break
-			}
-		}
-	}
-}
-
-// ----
-func init() {
-	if builtinModuleRegister == nil {
-		builtinModuleRegister = make(map[string]*builtinModule)
-	}
-}

byte-slider.go

@@ -18,17 +18,17 @@ func NewByteSlider(size int) *ByteSlider {
 	}
 }
 
-func (slider *ByteSlider) PushEnd(b byte) {
-	if slider.length == cap(slider.buf) {
-		slider.length--
-		for i := 0; i < slider.length; i++ {
-			slider.buf[i] = slider.buf[i+1]
+func (self *ByteSlider) PushEnd(b byte) {
+	if self.length == cap(self.buf) {
+		self.length--
+		for i := 0; i < self.length; i++ {
+			self.buf[i] = self.buf[i+1]
 		}
 	}
-	slider.buf[slider.length] = b
-	slider.length++
+	self.buf[self.length] = b
+	self.length++
 }
 
-func (slider *ByteSlider) Equal(target []byte) bool {
-	return target != nil && bytes.Equal(slider.buf, target)
+func (self *ByteSlider) Equal(target []byte) bool {
+	return target != nil && bytes.Equal(self.buf, target)
 }

context.go

@@ -0,0 +1,42 @@
+// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
+// All rights reserved.
+
+// context.go
+package expr
+
+// ---- Function template
+type FuncTemplate func(ctx ExprContext, name string, args []any) (result any, err error)
+
+// ---- Functor interface
+type Functor interface {
+	Invoke(ctx ExprContext, name string, args []any) (result any, err error)
+}
+
+type simpleFunctor struct {
+	f FuncTemplate
+}
+
+func (functor *simpleFunctor) Invoke(ctx ExprContext, name string, args []any) (result any, err error) {
+	return functor.f(ctx, name, args)
+}
+
+// ---- Function Info
+type ExprFunc interface {
+	Name() string
+	MinArgs() int
+	MaxArgs() int
+	Functor() Functor
+}
+
+// ----Expression Context
+type ExprContext interface {
+	Clone() ExprContext
+	GetVar(varName string) (value any, exists bool)
+	SetVar(varName string, value any)
+	setVar(varName string, value any)
+	EnumVars(func(name string) (accept bool)) (varNames []string)
+	EnumFuncs(func(name string) (accept bool)) (funcNames []string)
+	GetFuncInfo(name string) ExprFunc
+	Call(name string, args []any) (result any, err error)
+	RegisterFunc(name string, f Functor, minArgs, maxArgs int)
+}

control.go

@@ -0,0 +1,62 @@
+// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
+// All rights reserved.
+
+// control.go
+package expr
+
+import "strings"
+
+// Preset control variables
+const (
+	ControlLastResult   = "last"
+	ControlBoolShortcut = "_bool_shortcut"
+	ControlImportPath   = "_import_path"
+)
+
+// Other control variables
+const (
+	control_export_all = "_export_all"
+)
+
+// Initial values
+const (
+	init_import_path = "~/.local/lib/go-pkg/expr:/usr/local/lib/go-pkg/expr:/usr/lib/go-pkg/expr"
+)
+
+func initDefaultVars(ctx ExprContext) {
+	ctx.SetVar(ControlBoolShortcut, true)
+	ctx.SetVar(ControlImportPath, init_import_path)
+}
+
+func enable(ctx ExprContext, name string) {
+	if strings.HasPrefix(name, "_") {
+		ctx.SetVar(name, true)
+	} else {
+		ctx.SetVar("_"+name, true)
+	}
+}
+
+func disable(ctx ExprContext, name string) {
+	if strings.HasPrefix(name, "_") {
+		ctx.SetVar(name, false)
+	} else {
+		ctx.SetVar("_"+name, false)
+	}
+}
+
+func isEnabled(ctx ExprContext, name string) (status bool) {
+	if v, exists := ctx.GetVar(name); exists {
+		if b, ok := v.(bool); ok {
+			status = b
+		}
+	}
+	return
+}
+
+func getControlString(ctx ExprContext, name string) (s string, exists bool) {
+	var v any
+	if v, exists = ctx.GetVar(name); exists {
+		s, exists = v.(string)
+	}
+	return
+}

data-cursor.go

@@ -1,307 +0,0 @@
-// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
-// All rights reserved.
-
-// data-cursors.go
-package expr
-
-import (
-	"io"
-	"slices"
-
-	"git.portale-stac.it/go-pkg/expr/kern"
-)
-
-type dataCursor struct {
-	ds        map[string]kern.Functor
-	ctx       kern.ExprContext
-	initState bool // true if no item has produced yet (this replace di initial Next() call in the contructor)
-	// cursorValid bool // true if resource is nil or if clean has not yet been called
-	index     int64
-	count     int64
-	current   any
-	lastErr   error
-	resource  any
-	nextFunc  kern.Functor
-	cleanFunc kern.Functor
-	resetFunc kern.Functor
-}
-
-func NewDataCursor(ctx kern.ExprContext, ds map[string]kern.Functor, resource any) (dc *dataCursor) {
-	dc = &dataCursor{
-		ds:        ds,
-		initState: true,
-		// cursorValid: true,
-		index:     -1,
-		count:     0,
-		current:   nil,
-		lastErr:   nil,
-		resource:  resource,
-		ctx:       ctx.Clone(),
-		nextFunc:  ds[kern.NextName],
-		cleanFunc: ds[kern.CleanName],
-		resetFunc: ds[kern.ResetName],
-	}
-	return
-}
-
-func (dc *dataCursor) Context() kern.ExprContext {
-	return dc.ctx
-}
-
-func (dc *dataCursor) TypeName() string {
-	return "DataCursor"
-}
-
-// func mapToString(m map[string]Functor) string {
-// 	var sb strings.Builder
-// 	sb.WriteByte('{')
-// 	for key, _ := range m {
-// 		if sb.Len() > 1 {
-// 			sb.WriteString(fmt.Sprintf(", %q: func(){}", key))
-// 		} else {
-// 			sb.WriteString(fmt.Sprintf("%q: func(){}", key))
-// 		}
-// 	}
-// 	sb.WriteByte('}')
-// 	return sb.String()
-// }
-
-func (dc *dataCursor) String() string {
-	return "$()"
-	/*
-	   var sb strings.Builder
-	   sb.WriteString(fmt.Sprintf(`$(
-	   index: %d,
-	   ds:    %s,
-	   ctx:   `, dc.index, mapToString(dc.ds)))
-	   CtxToBuilder(&sb, dc.ctx, 1)
-	   sb.WriteByte(')')
-	   return sb.String()
-	*/
-}
-
-func (dc *dataCursor) HasOperation(name string) (exists bool) {
-	exists = slices.Contains([]string{kern.CleanName, kern.ResetName, kern.CurrentName, kern.IndexName}, name)
-	if !exists {
-		f, ok := dc.ds[name]
-		exists = ok && kern.IsFunctor(f)
-	}
-	return
-}
-
-func (dc *dataCursor) CallOperation(name string, args map[string]any) (value any, err error) {
-	if name == kern.IndexName {
-		value = int64(dc.Index())
-	} else if name == kern.CleanName {
-		err = dc.Clean()
-	} else if name == kern.ResetName {
-		err = dc.Reset()
-	} else if functor, ok := dc.ds[name]; ok && kern.IsFunctor(functor) {
-		ctx := kern.CloneContext(dc.ctx)
-		value, err = functor.InvokeNamed(ctx, name, args)
-		kern.ExportObjects(dc.ctx, ctx)
-	} else {
-		err = kern.ErrNoOperation(name)
-	}
-	return
-}
-
-// func (dc *dataCursor) Reset() (err error) {
-// 	if dc.resetFunc != nil {
-// 		if dc.resource != nil {
-// 			ctx := cloneContext(dc.ctx)
-// 			actualParams := bindActualParams(dc.resetFunc, []any{dc.resource})
-// 			_, err = dc.resetFunc.InvokeNamed(ctx, ResetName, actualParams)
-// 			exportObjects(dc.ctx, ctx)
-// 			dc.index = -1
-// 			dc.count = 0
-// 			dc.initState = true
-// 			dc.current = nil
-// 			dc.lastErr = nil
-// 		} else {
-// 			err = errInvalidDataSource()
-// 		}
-// 	} else {
-// 		err = errNoOperation(ResetName)
-// 	}
-// 	return
-// }
-
-func (dc *dataCursor) Reset() (err error) {
-	if dc.resetFunc != nil {
-		ctx := kern.CloneContext(dc.ctx)
-		actualParams := kern.BindActualParams(dc.resetFunc, []any{dc.resource})
-		_, err = dc.resetFunc.InvokeNamed(ctx, kern.ResetName, actualParams)
-		kern.ExportObjects(dc.ctx, ctx)
-	}
-	dc.index = -1
-	dc.count = 0
-	dc.initState = true
-	dc.current = nil
-	dc.lastErr = nil
-	return
-}
-
-func (dc *dataCursor) Clean() (err error) {
-	if dc.cleanFunc != nil {
-		ctx := kern.CloneContext(dc.ctx)
-		actualParams := kern.BindActualParams(dc.cleanFunc, []any{dc.resource})
-		_, err = dc.cleanFunc.InvokeNamed(ctx, kern.CleanName, actualParams)
-		kern.ExportObjects(dc.ctx, ctx)
-	}
-	dc.lastErr = io.EOF
-	return
-}
-
-// func (dc *dataCursor) Clean() (err error) {
-// 	if dc.cleanFunc != nil {
-// 		if dc.resource != nil {
-// 			ctx := cloneContext(dc.ctx)
-// 			actualParams := bindActualParams(dc.cleanFunc, []any{dc.resource})
-// 			_, err = dc.cleanFunc.InvokeNamed(ctx, CleanName, actualParams)
-// 			exportObjects(dc.ctx, ctx)
-// 		} else {
-// 			err = errInvalidDataSource()
-// 		}
-// 	} else {
-// 		err = errNoOperation(CleanName)
-// 	}
-// 	return
-// }
-
-func (dc *dataCursor) Current() (item any, err error) { // must return io.EOF at the last item
-	dc.init()
-
-	if dc.current != nil {
-		item = dc.current
-	} else {
-		err = io.EOF
-	}
-	return
-}
-
-func (dc *dataCursor) checkFilter(filter kern.Functor, item any) (accepted bool, err error) {
-	var v any
-	var ok bool
-	ctx := kern.CloneContext(dc.ctx)
-
-	actualParams := kern.BindActualParams(filter, []any{item, dc.index})
-	if v, err = filter.InvokeNamed(ctx, kern.FilterName, actualParams); err == nil && v != nil {
-		if accepted, ok = v.(bool); !ok {
-			accepted = true // NOTE: A non-boolean value that is not nil means the item has been accepted
-		}
-	}
-	return
-}
-
-func (dc *dataCursor) mapItem(mapper kern.Functor, item any) (mappedItem any, err error) {
-	ctx := kern.CloneContext(dc.ctx)
-	actualParams := kern.BindActualParams(mapper, []any{item, dc.index})
-	mappedItem, err = mapper.InvokeNamed(ctx, kern.MapName, actualParams)
-	return
-}
-
-func (dc *dataCursor) init() {
-	if dc.initState {
-		dc.initState = false
-		dc.Next()
-	}
-}
-
-func (dc *dataCursor) Next() (current any, err error) { // must return io.EOF after the last item
-	if dc.initState {
-		dc.init()
-	} else if err = dc.lastErr; err != nil {
-		return
-	}
-	current = dc.current
-	filter := dc.ds[kern.FilterName]
-	mapper := dc.ds[kern.MapName]
-	var item any
-	for item == nil && dc.lastErr == nil {
-		ctx := kern.CloneContext(dc.ctx)
-		dc.index++
-
-		actualParams := kern.BindActualParams(dc.nextFunc, []any{dc.resource, dc.index})
-		if item, dc.lastErr = dc.nextFunc.InvokeNamed(ctx, kern.NextName, actualParams); dc.lastErr == nil {
-			if item == nil {
-				dc.lastErr = io.EOF
-			} else {
-				accepted := true
-				if filter != nil {
-					if accepted, dc.lastErr = dc.checkFilter(filter, item); dc.lastErr != nil || !accepted {
-						item = nil
-					}
-				}
-				if accepted {
-					dc.count++
-				}
-				if item != nil && mapper != nil {
-					item, dc.lastErr = dc.mapItem(mapper, item)
-				}
-			}
-		}
-		kern.ExportObjects(dc.ctx, ctx)
-	}
-	dc.current = item
-	if dc.lastErr != nil {
-		dc.index--
-		dc.Clean()
-	}
-	return
-}
-
-// func (dc *dataCursor) Next() (current any, err error) { // must return io.EOF after the last item
-// 	if dc.initState {
-// 		dc.init()
-// 	} else if err = dc.lastErr; err != nil {
-// 		return
-// 	}
-// 	current = dc.current
-// 	if dc.resource != nil {
-// 		filter := dc.ds[FilterName]
-// 		mapper := dc.ds[MapName]
-// 		var item any
-// 		for item == nil && dc.lastErr == nil {
-// 			ctx := cloneContext(dc.ctx)
-// 			dc.index++
-
-// 			actualParams := bindActualParams(dc.nextFunc, []any{dc.resource, dc.index})
-// 			if item, dc.lastErr = dc.nextFunc.InvokeNamed(ctx, NextName, actualParams); dc.lastErr == nil {
-// 				if item == nil {
-// 					dc.lastErr = io.EOF
-// 				} else {
-// 					accepted := true
-// 					if filter != nil {
-// 						if accepted, dc.lastErr = dc.checkFilter(filter, item); dc.lastErr != nil || !accepted {
-// 							item = nil
-// 						}
-// 					}
-// 					if accepted {
-// 						dc.count++
-// 					}
-// 					if item != nil && mapper != nil {
-// 						item, dc.lastErr = dc.mapItem(mapper, item)
-// 					}
-// 				}
-// 			}
-// 			exportObjects(dc.ctx, ctx)
-// 		}
-// 		dc.current = item
-// 		if dc.lastErr != nil {
-// 			dc.index--
-// 			dc.Clean()
-// 		}
-// 	} else {
-// 		dc.lastErr = errInvalidDataSource()
-// 	}
-// 	return
-// }
-
-func (dc *dataCursor) Index() int64 {
-	return dc.index - 1
-}
-
-func (dc *dataCursor) Count() int64 {
-	return dc.count
-}

dict-iterator.go

@@ -1,223 +0,0 @@
-// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
-// All rights reserved.
-
-// dict-iterator.go
-package expr
-
-import (
-	"fmt"
-	"io"
-	"slices"
-	"strings"
-
-	"git.portale-stac.it/go-pkg/expr/kern"
-)
-
-type dictIterMode int
-
-const (
-	dictIterModeKeys dictIterMode = iota
-	dictIterModeValues
-	dictIterModeItems
-)
-
-type DictIterator struct {
-	a        *kern.DictType
-	count    int64
-	index    int64
-	keys     []any
-	iterMode dictIterMode
-}
-
-type sortType int
-
-const (
-	sortTypeNone sortType = iota
-	sortTypeAsc
-	sortTypeDesc
-	sortTypeDefault = sortTypeAsc
-)
-
-func (it *DictIterator) makeKeys(m map[any]any, sort sortType) {
-	it.keys = make([]any, 0, len(m))
-
-	if sort == sortTypeNone {
-		for keyAny := range m {
-			it.keys = append(it.keys, keyAny)
-		}
-	} else {
-		scalarMap := make(map[string]any, len(m))
-		scalerKeys := make([]string, 0, len(m))
-		for keyAny := range m {
-			keyStr := fmt.Sprint(keyAny)
-			scalarMap[keyStr] = keyAny
-			scalerKeys = append(scalerKeys, keyStr)
-		}
-
-		switch sort {
-		case sortTypeAsc:
-			slices.Sort(scalerKeys)
-		case sortTypeDesc:
-			slices.Sort(scalerKeys)
-			slices.Reverse(scalerKeys)
-		}
-		for _, keyStr := range scalerKeys {
-			it.keys = append(it.keys, scalarMap[keyStr])
-		}
-	}
-}
-
-func NewDictIterator(dict *kern.DictType, args []any) (it *DictIterator, err error) {
-	var sortType = sortTypeNone
-	var s string
-	var argAny any
-
-	dictIt := &DictIterator{a: dict, count: 0, index: -1, keys: nil, iterMode: dictIterModeKeys}
-	if len(args) > 0 {
-		argAny = args[0]
-	} else {
-		argAny = "default"
-	}
-	if s, err = kern.ToGoString(argAny, "sort type"); err == nil {
-		switch strings.ToLower(s) {
-		case "a", "asc":
-			sortType = sortTypeAsc
-		case "d", "desc":
-			sortType = sortTypeDesc
-		case "n", "none", "nosort", "no-sort":
-			sortType = sortTypeNone
-		case "", "default":
-			sortType = sortTypeDefault
-		default:
-			err = fmt.Errorf("invalid sort type %q", s)
-		}
-
-		if err == nil {
-			if len(args) > 1 {
-				argAny = args[1]
-			} else {
-				argAny = "default"
-			}
-
-			if s, err = kern.ToGoString(argAny, "iteration mode"); err == nil {
-				switch strings.ToLower(s) {
-				case "k", "key", "keys":
-					dictIt.iterMode = dictIterModeKeys
-				case "v", "value", "values":
-					dictIt.iterMode = dictIterModeValues
-				case "i", "item", "items":
-					dictIt.iterMode = dictIterModeItems
-				case "", "default":
-					dictIt.iterMode = dictIterModeKeys
-				default:
-					err = fmt.Errorf("invalid iteration mode %q", s)
-				}
-			}
-		}
-	}
-
-	dictIt.makeKeys(*dict, sortType)
-	return dictIt, err
-}
-
-func NewMapIterator(m map[any]any) (it *DictIterator) {
-	it = &DictIterator{a: (*kern.DictType)(&m), count: 0, index: -1, keys: nil}
-	it.makeKeys(m, sortTypeNone)
-	return
-}
-
-func (it *DictIterator) String() string {
-	var l = int64(0)
-	if it.a != nil {
-		l = int64(len(*it.a))
-	}
-	return fmt.Sprintf("$({#%d})", l)
-}
-
-func (it *DictIterator) TypeName() string {
-	return "DictIterator"
-}
-
-func (it *DictIterator) HasOperation(name string) bool {
-	// yes := name == NextName || name == ResetName || name == IndexName || name == CountName || name == CurrentName
-	yes := slices.Contains([]string{kern.NextName, kern.ResetName, kern.IndexName, kern.CountName, kern.CurrentName, kern.CleanName, kern.KeyName, kern.ValueName}, name)
-	return yes
-}
-
-func (it *DictIterator) CallOperation(name string, args map[string]any) (v any, err error) {
-	switch name {
-	case kern.NextName:
-		v, err = it.Next()
-	case kern.ResetName:
-		err = it.Reset()
-	case kern.CleanName:
-		err = it.Clean()
-	case kern.IndexName:
-		v = int64(it.Index())
-	case kern.CurrentName:
-		v, err = it.Current()
-	case kern.CountName:
-		v = it.count
-	case kern.KeyName:
-		if it.index >= 0 && it.index < int64(len(it.keys)) {
-			v = it.keys[it.index]
-		} else {
-			err = io.EOF
-		}
-	case kern.ValueName:
-		if it.index >= 0 && it.index < int64(len(it.keys)) {
-			a := *(it.a)
-			v = a[it.keys[it.index]]
-		} else {
-			err = io.EOF
-		}
-	default:
-		err = kern.ErrNoOperation(name)
-	}
-	return
-}
-
-func (it *DictIterator) Current() (item any, err error) {
-	if it.index >= 0 && it.index < int64(len(it.keys)) {
-		switch it.iterMode {
-		case dictIterModeKeys:
-			item = it.keys[it.index]
-		case dictIterModeValues:
-			a := *(it.a)
-			item = a[it.keys[it.index]]
-		case dictIterModeItems:
-			a := *(it.a)
-			pair := []any{it.keys[it.index], a[it.keys[it.index]]}
-			item = kern.NewList(pair)
-		}
-	} else {
-		err = io.EOF
-	}
-	return
-}
-
-func (it *DictIterator) Next() (item any, err error) {
-	it.index++
-	if item, err = it.Current(); err != io.EOF {
-		it.count++
-	}
-	return
-}
-
-func (it *DictIterator) Index() int64 {
-	return it.index
-}
-
-func (it *DictIterator) Count() int64 {
-	return it.count
-}
-
-func (it *DictIterator) Reset() error {
-	it.index = -1
-	it.count = 0
-	return nil
-}
-
-func (it *DictIterator) Clean() error {
-	return nil
-}

expr.go

@@ -1,16 +0,0 @@
-// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
-// All rights reserved.
-
-// expr.go
-package expr
-
-import (
-	kern "git.portale-stac.it/go-pkg/expr/kern"
-)
-
-// ----Expression interface
-type Expr interface {
-	kern.Typer
-	Eval(ctx kern.ExprContext) (result any, err error)
-	String() string
-}

expr_test.go

@@ -0,0 +1,72 @@
+// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
+// All rights reserved.
+
+// expr_test.go
+package expr
+
+import (
+	"fmt"
+	"strings"
+	"testing"
+)
+
+func TestExpr(t *testing.T) {
+	type inputType struct {
+		source     string
+		wantResult any
+		wantErr    error
+	}
+
+	inputs := []inputType{
+		/*   1 */ {`fact=func(n){(n)?{1}::{n*fact(n-1)}}; fact(5)`, int64(120), nil},
+	}
+
+	succeeded := 0
+	failed := 0
+
+	inputs1 := []inputType{
+		{`f=openFile("/tmp/test2.txt"); line=readFile(f); closeFile(f); line`, "ciao", nil},
+		//{`f = func(op){op()}; f(func(){2})`, int64(2), nil},
+	}
+
+	for i, input := range inputs1 {
+		var expr Expr
+		var gotResult any
+		var gotErr error
+
+		ctx := NewSimpleFuncStore()
+		// ImportMathFuncs(ctx)
+		// ImportImportFunc(ctx)
+		ImportOsFuncs(ctx)
+		parser := NewParser(ctx)
+
+		logTest(t, i+1, input.source, input.wantResult, input.wantErr)
+
+		r := strings.NewReader(input.source)
+		scanner := NewScanner(r, DefaultTranslations())
+
+		good := true
+		if expr, gotErr = parser.Parse(scanner); gotErr == nil {
+			gotResult, gotErr = expr.Eval(ctx)
+		}
+
+		if gotResult != input.wantResult {
+			t.Errorf("%d: %q -> result = %v [%T], want %v [%T]", i+1, input.source, gotResult, gotResult, input.wantResult, input.wantResult)
+			good = false
+		}
+
+		if gotErr != input.wantErr {
+			if input.wantErr == nil || gotErr == nil || (gotErr.Error() != input.wantErr.Error()) {
+				t.Errorf("%d: %q -> err = <%v>, want <%v>", i+1, input.source, gotErr, input.wantErr)
+				good = false
+			}
+		}
+
+		if good {
+			succeeded++
+		} else {
+			failed++
+		}
+	}
+	t.Log(fmt.Sprintf("test count: %d, succeeded count: %d, failed count: %d", len(inputs), succeeded, failed))
+}

func-import.go

@@ -0,0 +1,142 @@
+// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
+// All rights reserved.
+
+// func-import.go
+package expr
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"os"
+	"path"
+	"path/filepath"
+	"strings"
+)
+
+const ENV_EXPR_PATH = "EXPR_PATH"
+
+func importFunc(ctx ExprContext, name string, args []any) (result any, err error) {
+	return importGeneral(ctx, name, args)
+}
+
+func includeFunc(ctx ExprContext, name string, args []any) (result any, err error) {
+	enable(ctx, control_export_all)
+	return importGeneral(ctx, name, args)
+}
+
+func importGeneral(ctx ExprContext, name string, args []any) (result any, err error) {
+	var dirList []string
+
+	dirList = addEnvImportDirs(dirList)
+	dirList = addPresetImportDirs(ctx, dirList)
+	result, err = doImport(ctx, name, dirList, NewFlatArrayIterator(args))
+	return
+}
+
+func checkStringParamExpected(funcName string, paramValue any, paramPos int) (err error) {
+	if !(isString(paramValue) /*|| isList(paramValue)*/) {
+		err = fmt.Errorf("%s(): param nr %d has wrong type %T, string expected", funcName, paramPos+1, paramValue)
+	}
+	return
+}
+
+func addEnvImportDirs(dirList []string) []string {
+	if dirSpec, exists := os.LookupEnv(ENV_EXPR_PATH); exists {
+		dirs := strings.Split(dirSpec, ":")
+		if dirList == nil {
+			dirList = dirs
+		} else {
+			dirList = append(dirList, dirs...)
+		}
+	}
+	return dirList
+}
+
+func addPresetImportDirs(ctx ExprContext, dirList []string) []string {
+	if dirSpec, exists := getControlString(ctx, ControlImportPath); exists {
+		dirs := strings.Split(dirSpec, ":")
+		if dirList == nil {
+			dirList = dirs
+		} else {
+			dirList = append(dirList, dirs...)
+		}
+	}
+	return dirList
+}
+
+func isFile(filePath string) bool {
+	info, err := os.Stat(filePath)
+	return (err == nil || errors.Is(err, os.ErrExist)) && info.Mode().IsRegular()
+}
+
+func searchAmongPath(filename string, dirList []string) (filePath string) {
+	for _, dir := range dirList {
+		if fullPath := path.Join(dir, filename); isFile(fullPath) {
+			filePath = fullPath
+			break
+		}
+	}
+	return
+}
+
+func isPathRelative(filePath string) bool {
+	unixPath := filepath.ToSlash(filePath)
+	return strings.HasPrefix(unixPath, "./") || strings.HasPrefix(unixPath, "../")
+}
+
+func makeFilepath(filename string, dirList []string) (filePath string, err error) {
+	if path.IsAbs(filename) || isPathRelative(filename) {
+		if isFile(filename) {
+			filePath = filename
+		}
+	} else {
+		filePath = searchAmongPath(filename, dirList)
+	}
+	if len(filePath) == 0 {
+		err = fmt.Errorf("source file %q not found", filename)
+	}
+	return
+}
+
+func doImport(ctx ExprContext, name string, dirList []string, it Iterator) (result any, err error) {
+	var v any
+	var sourceFilepath string
+
+	for v, err = it.Next(); err == nil; v, err = it.Next() {
+		if err = checkStringParamExpected(name, v, it.Index()); err != nil {
+			break
+		}
+		if sourceFilepath, err = makeFilepath(v.(string), dirList); err != nil {
+			break
+		}
+		var file *os.File
+		if file, err = os.Open(sourceFilepath); err == nil {
+			defer file.Close()
+			var expr *ast
+			scanner := NewScanner(file, DefaultTranslations())
+			parser := NewParser(ctx)
+			if expr, err = parser.parseGeneral(scanner, true, true); err == nil {
+				result, err = expr.eval(ctx, false)
+			}
+			if err != nil {
+				break
+			}
+		} else {
+			break
+		}
+	}
+	if err != nil {
+		if err == io.EOF {
+			err = nil
+		} else {
+			result = nil
+		}
+	}
+	return
+}
+
+func ImportImportFuncs(ctx ExprContext) {
+	ctx.RegisterFunc("import", &simpleFunctor{f: importFunc}, 1, -1)
+	ctx.RegisterFunc("include", &simpleFunctor{f: includeFunc}, 1, -1)
+}

func-math.go

@@ -0,0 +1,114 @@
+// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
+// All rights reserved.
+
+// funcs-math.go
+package expr
+
+import (
+	"fmt"
+	"io"
+)
+
+func checkNumberParamExpected(funcName string, paramValue any, paramPos int) (err error) {
+	if !(isNumber(paramValue) || isList(paramValue)) {
+		err = fmt.Errorf("%s(): param nr %d has wrong type %T, number expected", funcName, paramPos+1, paramValue)
+	}
+	return
+}
+
+func doAdd(ctx ExprContext, name string, it Iterator) (result any, err error) {
+	var sumAsFloat = false
+	var floatSum float64 = 0.0
+	var intSum int64 = 0
+	var v any
+
+	for v, err = it.Next(); err == nil; v, err = it.Next() {
+		if err = checkNumberParamExpected(name, v, it.Index()); err != nil {
+			break
+		}
+
+		if array, ok := v.([]any); ok {
+			if v, err = doAdd(ctx, name, NewFlatArrayIterator(array)); err != nil {
+				break
+			}
+		}
+
+		if !sumAsFloat && isFloat(v) {
+			sumAsFloat = true
+			floatSum = float64(intSum)
+		}
+		if sumAsFloat {
+			floatSum += numAsFloat(v)
+		} else {
+			iv, _ := v.(int64)
+			intSum += iv
+		}
+	}
+	if err == nil || err == io.EOF {
+		err = nil
+		if sumAsFloat {
+			result = floatSum
+		} else {
+			result = intSum
+		}
+	}
+	return
+}
+
+func addFunc(ctx ExprContext, name string, args []any) (result any, err error) {
+	result, err = doAdd(ctx, name, NewFlatArrayIterator(args))
+	return
+}
+
+func doMul(ctx ExprContext, name string, it Iterator) (result any, err error) {
+	var mulAsFloat = false
+	var floatProd float64 = 1.0
+	var intProd int64 = 1
+	var v any
+
+	for v, err = it.Next(); err == nil; v, err = it.Next() {
+		if err = checkNumberParamExpected(name, v, it.Index()); err != nil {
+			break
+		}
+
+		if array, ok := v.([]any); ok {
+			if v, err = doAdd(ctx, name, NewFlatArrayIterator(array)); err != nil {
+				break
+			}
+		}
+
+		if !mulAsFloat && isFloat(v) {
+			mulAsFloat = true
+			floatProd = float64(intProd)
+		}
+		if mulAsFloat {
+			floatProd *= numAsFloat(v)
+		} else {
+			iv, _ := v.(int64)
+			intProd *= iv
+		}
+	}
+	if err == nil || err == io.EOF {
+		err = nil
+		if mulAsFloat {
+			result = floatProd
+		} else {
+			result = intProd
+		}
+	}
+	return
+}
+
+func mulFunc(ctx ExprContext, name string, args []any) (result any, err error) {
+	result, err = doMul(ctx, name, NewFlatArrayIterator(args))
+	return
+}
+
+func ImportMathFuncs(ctx ExprContext) {
+	ctx.RegisterFunc("add", &simpleFunctor{f: addFunc}, 0, -1)
+	ctx.RegisterFunc("mul", &simpleFunctor{f: mulFunc}, 0, -1)
+}
+
+func init() {
+	registerImport("math.arith", ImportMathFuncs)
+}

func-os.go

@@ -0,0 +1,164 @@
+// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
+// All rights reserved.
+
+// func-os.go
+package expr
+
+import (
+	"bufio"
+	"fmt"
+	"io"
+	"os"
+)
+
+type osHandle interface {
+	getFile() *os.File
+}
+
+type osWriter struct {
+	fh     *os.File
+	writer *bufio.Writer
+}
+
+func (h *osWriter) getFile() *os.File {
+	return h.fh
+}
+
+type osReader struct {
+	fh     *os.File
+	reader *bufio.Reader
+}
+
+func (h *osReader) getFile() *os.File {
+	return h.fh
+}
+
+func createFileFunc(ctx ExprContext, name string, args []any) (result any, err error) {
+	var filePath string
+	if len(args) > 0 {
+		filePath, _ = args[0].(string)
+	}
+
+	if len(filePath) > 0 {
+		var fh *os.File
+		if fh, err = os.Create(filePath); err == nil {
+			result = &osWriter{fh: fh, writer: bufio.NewWriter(fh)}
+		}
+	} else {
+		err = fmt.Errorf("%s(): missing the file path", name)
+	}
+	return
+}
+
+func openFileFunc(ctx ExprContext, name string, args []any) (result any, err error) {
+	var filePath string
+	if len(args) > 0 {
+		filePath, _ = args[0].(string)
+	}
+
+	if len(filePath) > 0 {
+		var fh *os.File
+		if fh, err = os.Open(filePath); err == nil {
+			result = &osReader{fh: fh, reader: bufio.NewReader(fh)}
+		}
+	} else {
+		err = fmt.Errorf("%s(): missing the file path", name)
+	}
+	return
+}
+
+func appendFileFunc(ctx ExprContext, name string, args []any) (result any, err error) {
+	var filePath string
+	if len(args) > 0 {
+		filePath, _ = args[0].(string)
+	}
+
+	if len(filePath) > 0 {
+		var fh *os.File
+		if fh, err = os.OpenFile(filePath, os.O_APPEND|os.O_WRONLY|os.O_CREATE, 0660); err == nil {
+			result = &osWriter{fh: fh, writer: bufio.NewWriter(fh)}
+		}
+	} else {
+		err = fmt.Errorf("%s(): missing the file path", name)
+	}
+	return
+}
+
+func closeFileFunc(ctx ExprContext, name string, args []any) (result any, err error) {
+	var handle osHandle
+
+	if len(args) > 0 {
+		handle, _ = args[0].(osHandle)
+	}
+
+	if handle != nil {
+		if fh := handle.getFile(); fh != nil {
+			if w, ok := handle.(*osWriter); ok {
+				err = w.writer.Flush()
+			}
+			if err == nil {
+				err = fh.Close()
+			}
+		}
+	} else {
+		err = fmt.Errorf("%s(): invalid file handle", name)
+	}
+	result = err == nil
+	return
+}
+
+func writeFileFunc(ctx ExprContext, name string, args []any) (result any, err error) {
+	var handle osHandle
+
+	if len(args) > 0 {
+		handle, _ = args[0].(osHandle)
+	}
+
+	if handle != nil {
+		if fh := handle.getFile(); fh != nil {
+			if w, ok := handle.(*osWriter); ok {
+				result, err = fmt.Fprint(w.writer, args[1:]...)
+			}
+		}
+	}
+	return
+}
+
+func readFileFunc(ctx ExprContext, name string, args []any) (result any, err error) {
+	var handle osHandle
+
+	if len(args) > 0 {
+		handle, _ = args[0].(osHandle)
+	}
+
+	if handle != nil {
+		if fh := handle.getFile(); fh != nil {
+			if r, ok := handle.(*osReader); ok {
+				var limit byte = '\n'
+				var v string
+				if len(args) > 1 {
+					if s, ok := args[1].(string); ok && len(s) > 0 {
+						limit = s[0]
+					}
+				}
+				if v, err = r.reader.ReadString(limit); err == nil || err == io.EOF {
+					if len(v) > 0 && v[len(v)-1] == limit {
+						result = v[0 : len(v)-1]
+					} else {
+						result = v
+					}
+				}
+			}
+		}
+	}
+	return
+}
+
+func ImportOsFuncs(ctx ExprContext) {
+	ctx.RegisterFunc("openFile", &simpleFunctor{f: openFileFunc}, 1, 1)
+	ctx.RegisterFunc("appendFile", &simpleFunctor{f: appendFileFunc}, 1, 1)
+	ctx.RegisterFunc("createFile", &simpleFunctor{f: createFileFunc}, 1, 1)
+	ctx.RegisterFunc("writeFile", &simpleFunctor{f: writeFileFunc}, 1, -1)
+	ctx.RegisterFunc("readFile", &simpleFunctor{f: readFileFunc}, 1, 2)
+	ctx.RegisterFunc("closeFile", &simpleFunctor{f: closeFileFunc}, 1, 1)
+}

function-register.go

@@ -0,0 +1,47 @@
+// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
+// All rights reserved.
+
+// function-register.go
+package expr
+
+import (
+	"path/filepath"
+)
+
+var functionRegister map[string]func(ExprContext)
+
+func registerImport(name string, importFunc func(ExprContext)) {
+	if functionRegister == nil {
+		functionRegister = make(map[string]func(ExprContext))
+	}
+	functionRegister[name] = importFunc
+}
+
+func ImportInContext(ctx ExprContext, name string) (exists bool) {
+	var importFunc func(ExprContext)
+	if importFunc, exists = functionRegister[name]; exists {
+		importFunc(ctx)
+	}
+	return
+}
+
+func ImportInContextByGlobPattern(ctx ExprContext, pattern string) (count int, err error) {
+	var matched bool
+	for name, importFunc := range functionRegister {
+		if matched, err = filepath.Match(pattern, name); err == nil {
+			if matched {
+				count++
+				importFunc(ctx)
+			}
+		} else {
+			break
+		}
+	}
+	return
+}
+
+func init() {
+	if functionRegister == nil {
+		functionRegister = make(map[string]func(ExprContext))
+	}
+}

function.go

@@ -1,387 +0,0 @@
-// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
-// All rights reserved.
-
-// function.go
-package expr
-
-import (
-	"fmt"
-	"strings"
-
-	"git.portale-stac.it/go-pkg/expr/kern"
-)
-
-// ---- Function template
-// type FuncTemplate func(ctx expr.ExprContext, name string, args map[string]any) (result any, err error)
-
-// ---- Common functor definition
-type BaseFunctor struct {
-	info kern.ExprFunc
-}
-
-func (functor *BaseFunctor) ToString(opt kern.FmtOpt) (s string) {
-	if functor.info != nil {
-		s = functor.info.ToString(opt)
-	} else {
-		s = "func(){}"
-	}
-	return s
-}
-
-func (functor *BaseFunctor) GetParams() (params []kern.ExprFuncParam) {
-	if functor.info != nil {
-		return functor.info.Params()
-	} else {
-		return []kern.ExprFuncParam{}
-	}
-}
-
-func (functor *BaseFunctor) SetFunc(info kern.ExprFunc) {
-	functor.info = info
-}
-
-func (functor *BaseFunctor) GetFunc() kern.ExprFunc {
-	return functor.info
-}
-
-func (functor *BaseFunctor) GetDefinitionContext() kern.ExprContext {
-	return nil
-}
-
-// ---- Function Parameters
-type paramFlags uint16
-
-const (
-	PfDefault paramFlags = 1 << iota
-	PfOptional
-	PfRepeat
-)
-
-type funcParamInfo struct {
-	name         string
-	flags        paramFlags
-	defaultValue any
-}
-
-func NewFuncParam(name string) kern.ExprFuncParam {
-	return &funcParamInfo{name: name}
-}
-
-func NewFuncParamFlag(name string, flags paramFlags) kern.ExprFuncParam {
-	return &funcParamInfo{name: name, flags: flags}
-}
-
-func NewFuncParamFlagDef(name string, flags paramFlags, defValue any) *funcParamInfo {
-	return &funcParamInfo{name: name, flags: flags, defaultValue: defValue}
-}
-
-func (param *funcParamInfo) Name() string {
-	return param.name
-}
-
-func (param *funcParamInfo) Type() string {
-	return kern.TypeAny
-}
-
-func (param *funcParamInfo) IsDefault() bool {
-	return (param.flags & PfDefault) != 0
-}
-
-func (param *funcParamInfo) IsOptional() bool {
-	return (param.flags & PfOptional) != 0
-}
-
-func (param *funcParamInfo) IsRepeat() bool {
-	return (param.flags & PfRepeat) != 0
-}
-
-func (param *funcParamInfo) DefaultValue() any {
-	return param.defaultValue
-}
-
-// --- Functions
-
-// funcInfo implements expr.ExprFunc
-type funcInfo struct {
-	name         string
-	minArgs      int
-	maxArgs      int
-	functor      kern.Functor
-	formalParams []kern.ExprFuncParam
-	returnType   string
-}
-
-func newFuncInfo(name string, functor kern.Functor, returnType string, params []kern.ExprFuncParam) (info *funcInfo, err error) {
-	var minArgs = 0
-	var maxArgs = 0
-	for _, p := range params {
-		if maxArgs == -1 {
-			return nil, fmt.Errorf("no more params can be specified after the ellipsis symbol: %q", p.Name())
-		}
-		if p.IsDefault() || p.IsOptional() {
-			maxArgs++
-		} else if maxArgs == minArgs {
-			minArgs++
-			maxArgs++
-		} else {
-			return nil, fmt.Errorf("can't specify non-optional param after optional ones: %q", p.Name())
-		}
-		if p.IsRepeat() {
-			minArgs--
-			maxArgs = -1
-		}
-	}
-
-	info = &funcInfo{
-		name: name, minArgs: minArgs, maxArgs: maxArgs, functor: functor, returnType: returnType, formalParams: params,
-	}
-	functor.SetFunc(info)
-	return info, nil
-}
-
-func (info *funcInfo) Params() []kern.ExprFuncParam {
-	return info.formalParams
-}
-
-func (info *funcInfo) ReturnType() string {
-	return info.returnType
-}
-
-func (info *funcInfo) ToString(opt kern.FmtOpt) string {
-	var sb strings.Builder
-	if len(info.Name()) == 0 {
-		sb.WriteString("func")
-	} else {
-		sb.WriteString(info.Name())
-	}
-	sb.WriteByte('(')
-	if info.formalParams != nil {
-		for i, p := range info.formalParams {
-			if i > 0 {
-				sb.WriteString(", ")
-			}
-			sb.WriteString(p.Name())
-
-			if p.IsDefault() {
-				sb.WriteByte('=')
-				if s, ok := p.DefaultValue().(string); ok {
-					sb.WriteByte('"')
-					sb.WriteString(s)
-					sb.WriteByte('"')
-				} else {
-					sb.WriteString(fmt.Sprintf("%v", p.DefaultValue()))
-				}
-			}
-		}
-	}
-	if info.maxArgs < 0 {
-		sb.WriteString(" ...")
-	}
-	sb.WriteString("):")
-	if len(info.returnType) > 0 {
-		sb.WriteString(info.returnType)
-	} else {
-		sb.WriteString(kern.TypeAny)
-	}
-	sb.WriteString("{}")
-	return sb.String()
-}
-
-func (info *funcInfo) Name() string {
-	return info.name
-}
-
-func (info *funcInfo) MinArgs() int {
-	return info.minArgs
-}
-
-func (info *funcInfo) MaxArgs() int {
-	return info.maxArgs
-}
-
-func (info *funcInfo) Functor() kern.Functor {
-	return info.functor
-}
-
-func (info *funcInfo) AllocContext(parentCtx kern.ExprContext) (ctx kern.ExprContext) {
-	if defCtx := info.functor.GetDefinitionContext(); defCtx != nil {
-		ctx = defCtx.Clone()
-		ctx.SetParent(defCtx)
-	} else {
-		ctx = parentCtx.Clone()
-		ctx.SetParent(parentCtx)
-	}
-	return
-}
-
-func (info *funcInfo) ParamSpec(paramName string) kern.ExprFuncParam {
-	for _, spec := range info.formalParams {
-		if spec.Name() == paramName {
-			return spec
-		}
-	}
-	return nil
-}
-
-func initActualParams(ctx kern.ExprContext, info kern.ExprFunc, callTerm *term) (actualParams map[string]any, err error) {
-	var varArgs []any
-	var varName string
-
-	namedParamsStarted := false
-
-	formalParams := info.Params()
-	actualParams = make(map[string]any, len(formalParams))
-	if callTerm == nil {
-		return
-	}
-
-	for i, tree := range callTerm.children {
-		var paramValue any
-		paramCtx := ctx.Clone()
-		if paramValue, err = tree.Compute(paramCtx); err != nil {
-			break
-		}
-		if paramName, namedParam := kern.GetAssignVarName(tree); namedParam {
-			if info.ParamSpec(paramName) == nil {
-				err = fmt.Errorf("%s(): unknown param %q", info.Name(), paramName)
-				break
-			}
-			actualParams[paramName] = paramValue
-			namedParamsStarted = true
-		} else if !namedParamsStarted {
-			if varArgs != nil {
-				varArgs = append(varArgs, paramValue)
-			} else if i < len(formalParams) {
-				spec := formalParams[i]
-				if spec.IsRepeat() {
-					varArgs = make([]any, 0, len(callTerm.children)-i)
-					varArgs = append(varArgs, paramValue)
-					varName = spec.Name()
-				} else {
-					actualParams[spec.Name()] = paramValue
-				}
-			} else {
-				err = kern.ErrTooManyParams(info.Name(), len(formalParams), len(callTerm.children))
-				break
-			}
-		} else {
-			err = fmt.Errorf("%s(): positional param nr %d not allowed after named params", info.Name(), i+1)
-			break
-		}
-	}
-	if err == nil {
-		if varArgs != nil {
-			actualParams[varName] = varArgs
-		}
-	}
-	return
-}
-
-func (info *funcInfo) PrepareCall(name string, actualParams map[string]any) (err error) {
-	passedCount := len(actualParams)
-	if info.MinArgs() > passedCount {
-		err = kern.ErrTooFewParams(name, info.MinArgs(), info.MaxArgs(), passedCount)
-		return
-	}
-
-	if passedCount < len(info.formalParams) {
-		for _, p := range info.formalParams {
-			if _, exists := actualParams[p.Name()]; !exists {
-				if !p.IsDefault() {
-					break
-				}
-				if p.IsRepeat() {
-					varArgs := make([]any, 1)
-					varArgs[0] = p.DefaultValue()
-					actualParams[p.Name()] = varArgs
-				} else {
-					actualParams[p.Name()] = p.DefaultValue()
-				}
-			}
-		}
-	}
-
-	if info.MaxArgs() >= 0 && info.MaxArgs() < len(actualParams) {
-		err = kern.ErrTooManyParams(name, info.MaxArgs(), len(actualParams))
-	}
-	return
-}
-
-// ----- Call a function ---
-
-// func getAssignVarName(t *term) (name string, ok bool) {
-// 	if ok = t.symbol() == SymEqual; ok {
-// 		name = t.children[0].source()
-// 	}
-// 	return
-// }
-
-// func CallFunctionByTerm(parentCtx expr.ExprContext, name string, callTerm *term) (result any, err error) {
-// 	var actualParams map[string]any
-// 	if info, exists := GetFuncInfo(parentCtx, name); exists {
-// 		if actualParams, err = initActualParams(parentCtx, info, callTerm); err == nil {
-// 			ctx := info.AllocContext(parentCtx)
-// 			if err = info.PrepareCall(name, actualParams); err == nil {
-// 				functor := info.Functor()
-// 				result, err = functor.InvokeNamed(ctx, name, actualParams)
-// 				exportObjectsToParent(ctx)
-// 			}
-// 		}
-// 	} else {
-// 		err = fmt.Errorf("unknown function %s()", name)
-// 	}
-// 	return
-// }
-
-// func CallFunctionByArgs(parentCtx expr.ExprContext, name string, args []any) (result any, err error) {
-// 	var actualParams map[string]any
-// 	if info, exists := GetFuncInfo(parentCtx, name); exists {
-// 		functor := info.Functor()
-// 		actualParams = bindActualParams(functor, args)
-// 		ctx := info.AllocContext(parentCtx)
-// 		if err = info.PrepareCall(name, actualParams); err == nil {
-// 			result, err = functor.InvokeNamed(ctx, name, actualParams)
-// 			exportObjectsToParent(ctx)
-// 		}
-// 	} else {
-// 		err = fmt.Errorf("unknown function %s()", name)
-// 	}
-// 	return
-// }
-
-// func CallFunctionByParams(parentCtx expr.ExprContext, name string, actualParams map[string]any) (result any, err error) {
-// 	//var actualParams map[string]any
-// 	if info, exists := GetFuncInfo(parentCtx, name); exists {
-// 		functor := info.Functor()
-// 		ctx := info.AllocContext(parentCtx)
-// 		if err = info.PrepareCall(name, actualParams); err == nil {
-// 			result, err = functor.InvokeNamed(ctx, name, actualParams)
-// 			exportObjectsToParent(ctx)
-// 		}
-// 	} else {
-// 		err = fmt.Errorf("unknown function %s()", name)
-// 	}
-// 	return
-// }
-
-// func GetParam(args map[string]any, paramName string, paramNum int) (value any, exists bool) {
-// 	if value, exists = args[paramName]; !exists {
-// 		if paramNum > 0 && paramNum <= len(args) {
-// 			value, exists = args["arg"+strconv.Itoa(paramNum)]
-// 		}
-// 	}
-// 	return
-// }
-
-// func bindActualParams(functor Functor, args []any) (actualParams map[string]any) {
-// 	formalParams := functor.GetParams()
-// 	actualParams = make(map[string]any, len(args))
-// 	for i, arg := range args {
-// 		if i < len(formalParams) {
-// 			actualParams[formalParams[i].Name()] = arg
-// 		} else {
-// 			actualParams["arg"+strconv.Itoa(i+1)] = arg
-// 		}
-// 	}
-// 	return
-// }

global-context.go

@@ -1,126 +0,0 @@
-// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
-// All rights reserved.
-
-// global-context.go
-package expr
-
-import (
-	"path/filepath"
-	"strings"
-
-	"git.portale-stac.it/go-pkg/expr/kern"
-)
-
-//var globalCtx *SimpleStore
-
-func ImportInContext(ctx kern.ExprContext, name string) (exists bool) {
-	if globalCtx := ctx.GetGlobal(); globalCtx != nil {
-		var mod *builtinModule
-		if mod, exists = builtinModuleRegister[name]; exists {
-			mod.importFunc(globalCtx)
-			mod.imported = true
-		}
-	}
-	return
-}
-
-func ImportInContextByGlobPattern(ctx kern.ExprContext, pattern string) (count int, err error) {
-	if globalCtx := ctx.GetGlobal(); globalCtx != nil {
-		var matched bool
-		for name, mod := range builtinModuleRegister {
-			if matched, err = filepath.Match(pattern, name); err == nil {
-				if matched {
-					count++
-					mod.importFunc(globalCtx)
-					mod.imported = true
-				}
-			} else {
-				break
-			}
-		}
-	}
-	return
-}
-
-func GlobalCtrlSet(ctx kern.ExprContext, name string, newValue any) (currentValue any) {
-	if globalCtx := ctx.GetGlobal(); globalCtx != nil {
-		if !strings.HasPrefix(name, "_") {
-			name = "_" + name
-		}
-
-		currentValue, _ = globalCtx.GetVar(name)
-		globalCtx.SetVar(name, newValue)
-	}
-	return currentValue
-}
-
-func GlobalCtrlGet(ctx kern.ExprContext, name string) (currentValue any) {
-	if globalCtx := ctx.GetGlobal(); globalCtx != nil {
-		if !strings.HasPrefix(name, "_") {
-			name = "_" + name
-		}
-		currentValue, _ = globalCtx.GetVar(name)
-	}
-	return currentValue
-}
-
-func CtrlEnable(ctx kern.ExprContext, name string) (currentStatus bool) {
-	if !strings.HasPrefix(name, "_") {
-		name = "_" + name
-	}
-	if v, exists := ctx.GetVar(name); exists && kern.IsBool(v) {
-		currentStatus, _ = v.(bool)
-	}
-
-	ctx.SetVar(name, true)
-	return currentStatus
-}
-
-func CtrlDisable(ctx kern.ExprContext, name string) (currentStatus bool) {
-	if !strings.HasPrefix(name, "_") {
-		name = "_" + name
-	}
-	if v, exists := ctx.GetVar(name); exists && kern.IsBool(v) {
-		currentStatus, _ = v.(bool)
-	}
-
-	ctx.SetVar(name, false)
-	return currentStatus
-}
-
-// func CtrlIsEnabled(ctx ExprContext, name string) (status bool) {
-// 	var v any
-// 	var exists bool
-
-// 	if !strings.HasPrefix(name, "_") {
-// 		name = "_" + name
-// 	}
-
-// 	if v, exists = ctx.GetVar(name); !exists {
-// 		v, exists = globalCtx.GetVar(name)
-// 	}
-
-// 	if exists {
-// 		if b, ok := v.(bool); ok {
-// 			status = b
-// 		}
-// 	}
-// 	return
-// }
-
-func getControlString(ctx kern.ExprContext, name string) (s string, exists bool) {
-	if globalCtx := ctx.GetGlobal(); globalCtx != nil {
-		var v any
-		if v, exists = globalCtx.GetVar(name); exists {
-			s, exists = v.(string)
-		}
-	}
-	return
-}
-
-func InitGlobal() (ctx kern.ExprContext) {
-	ctx = NewSimpleStoreWithoutGlobalContext()
-	kern.InitDefaultVars(ctx)
-	ImportBuiltinsFuncs(ctx)
-	return
-}

go.mod

@@ -1,7 +1,3 @@
 module git.portale-stac.it/go-pkg/expr
 
-go 1.22.0
-
-toolchain go1.23.3
-
-require golang.org/x/exp v0.0.0-20241204233417-43b7b7cde48d
+go 1.21.6

go.sum

@@ -1,4 +0,0 @@
-github.com/yqylovy/goimportdot v0.0.0-20170519021755-eb181a7eeabe h1:bWYrKmmfv37uNgXTdwkLSKYiYPJ1yfWmjBnvtMyAYzk=
-github.com/yqylovy/goimportdot v0.0.0-20170519021755-eb181a7eeabe/go.mod h1:alTKUpAJ/zbp17qvZwcFNwzufrb5DljMDY4mgJlIHao=
-golang.org/x/exp v0.0.0-20241204233417-43b7b7cde48d h1:0olWaB5pg3+oychR51GUVCEsGkeCU/2JxjBgIo4f3M0=
-golang.org/x/exp v0.0.0-20241204233417-43b7b7cde48d/go.mod h1:qj5a5QZpwLU2NLQudwIN5koi3beDhSAlJwa67PuM98c=

graph.go

@@ -1,8 +1,6 @@
 // Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
 // All rights reserved.
 
-//go:build graph
-
 // graph.go
 package expr
 
@@ -55,7 +53,7 @@ func (r *Reticle) computeCharWidth() {
 			if v := ref.node.value(); v != nil {
 				ref.label = fmt.Sprintf("%v", v)
 			} else {
-				ref.label = ref.node.Source()
+				ref.label = ref.node.source()
 			}
 			r.colsWidth[c] = max(r.colsWidth[c], len(ref.label)+2) // +2 to make room for brakets
 		}

graph_test.go

@@ -1,9 +1,10 @@
 // Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
 // All rights reserved.
 
-//go:build graph
+// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
+// All rights reserved.
 
-// t_graph_test.go
+// graph_test.go
 package expr
 
 import (

helpers.go

@@ -6,23 +6,18 @@ package expr
 
 import (
 	"fmt"
-	"io"
-	"os"
 	"strings"
-
-	"git.portale-stac.it/go-pkg/expr/kern"
-	"git.portale-stac.it/go-pkg/expr/util"
 )
 
-func EvalString(ctx kern.ExprContext, source string) (result any, err error) {
+func EvalString(ctx ExprContext, source string) (result any, err error) {
 	var tree *ast
 
 	r := strings.NewReader(source)
 	scanner := NewScanner(r, DefaultTranslations())
-	parser := NewParser()
+	parser := NewParser(ctx)
 
 	if tree, err = parser.Parse(scanner); err == nil {
-		result, err = tree.Eval(ctx)
+		result, err = tree.eval(ctx, true)
 	}
 	return
 }
@@ -37,21 +32,18 @@ func EvalStringA(source string, args ...Arg) (result any, err error) {
 }
 
 func EvalStringV(source string, args []Arg) (result any, err error) {
-	ctx := NewSimpleStoreWithoutGlobalContext()
+	ctx := NewSimpleFuncStore()
 	for _, arg := range args {
-		if util.IsFunc(arg.Value) {
-			if f, ok := arg.Value.(kern.FuncTemplate); ok {
-				functor := kern.NewGolangFunctor(f)
-				// ctx.RegisterFunc(arg.Name, functor, 0, -1)
-				ctx.RegisterFunc(arg.Name, functor, kern.TypeAny, []kern.ExprFuncParam{
-					NewFuncParamFlagDef(kern.ParamValue, PfDefault|PfRepeat, 0),
-				})
+		if isFunc(arg.Value) {
+			if f, ok := arg.Value.(FuncTemplate); ok {
+				functor := &simpleFunctor{f: f}
+				ctx.RegisterFunc(arg.Name, functor, 0, -1)
 			} else {
 				err = fmt.Errorf("invalid function specification: %q", arg.Name)
 			}
-		} else if integer, ok := kern.AnyInteger(arg.Value); ok {
+		} else if integer, ok := anyInteger(arg.Value); ok {
 			ctx.SetVar(arg.Name, integer)
-		} else if float, ok := kern.AnyFloat(arg.Value); ok {
+		} else if float, ok := anyFloat(arg.Value); ok {
 			ctx.SetVar(arg.Name, float)
 		} else if _, ok := arg.Value.(string); ok {
 			ctx.SetVar(arg.Name, arg.Value)
@@ -67,24 +59,3 @@ func EvalStringV(source string, args []Arg) (result any, err error) {
 	}
 	return
 }
-
-func EvalStream(ctx kern.ExprContext, r io.Reader) (result any, err error) {
-	var tree *ast
-	scanner := NewScanner(r, DefaultTranslations())
-	parser := NewParser()
-
-	if tree, err = parser.Parse(scanner); err == nil {
-		result, err = tree.Eval(ctx)
-	}
-	return
-}
-
-func EvalFile(ctx kern.ExprContext, filePath string) (result any, err error) {
-	var fh *os.File
-	if fh, err = os.Open(filePath); err != nil {
-		return nil, err
-	}
-	defer fh.Close()
-	result, err = EvalStream(ctx, fh)
-	return
-}

helpers_test.go

@@ -0,0 +1,81 @@
+// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
+// All rights reserved.
+
+// helpers_test.go
+package expr
+
+import (
+	"fmt"
+	"testing"
+)
+
+func subtract(ctx ExprContext, name string, args []any) (result any, err error) {
+	if len(args) != 2 {
+		err = fmt.Errorf("%s(): requires exactly two arguments", name)
+		return
+	}
+	x, xok := args[0].(int64)
+	y, yok := args[1].(int64)
+	if xok && yok {
+		result = x - y
+	} else {
+		err = fmt.Errorf("expected integer (int64) arguments, got %T and %T values", x, y)
+	}
+	return
+}
+
+func TestEvalStringA(t *testing.T) {
+
+	source := `a + b * subtract(4,2)`
+	args := []Arg{
+		{"a", uint8(1)},
+		{"b", int8(2)},
+		{"subtract", FuncTemplate(subtract)},
+		// force coverage
+		{"a16", uint16(1)},
+		{"b16", int16(2)},
+		{"a32", uint32(1)},
+		{"b32", int32(2)},
+		{"a64", uint64(1)},
+		{"b64", int64(2)},
+		{"f32", float32(1.0)},
+		{"f64", float64(1.0)},
+	}
+
+	wantResult := int64(5)
+	gotResult, gotErr := EvalStringA(source, args...)
+	if value, ok := gotResult.(int64); ok && value != wantResult {
+		t.Errorf("Source %q got %v, want %v", source, gotResult, wantResult)
+		t.Errorf("Error: %v", gotErr)
+	}
+}
+
+func TestEvalString(t *testing.T) {
+
+	ctx := NewSimpleVarStore()
+	ctx.SetVar("a", uint8(1))
+	ctx.SetVar("b", int8(2))
+	ctx.SetVar("f", 2.0)
+	// force coverage
+	ctx.SetVar("a16", uint16(1))
+	ctx.SetVar("b16", int16(2))
+	ctx.SetVar("a32", uint32(1))
+	ctx.SetVar("b32", int32(2))
+	ctx.SetVar("a64", uint64(1))
+	ctx.SetVar("b64", int64(2))
+	ctx.SetVar("f32", float32(1.0))
+	ctx.SetVar("f64", float64(1.0))
+
+	// force coverage
+	ctx.GetFuncInfo("dummy")
+	ctx.Call("dummy", []any{})
+
+	source := `a + b * f`
+
+	wantResult := float64(5)
+	gotResult, gotErr := EvalString(ctx, source)
+	if value, ok := gotResult.(float64); ok && value != wantResult {
+		t.Errorf("Source %q got %v, want %v", source, gotResult, wantResult)
+		t.Errorf("Error: %v", gotErr)
+	}
+}

hook_test.txt

@@ -0,0 +1,3 @@
+First test
+next commit
+nr 3

import-utils.go

@@ -1,127 +0,0 @@
-// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
-// All rights reserved.
-
-// import-utils.go
-package expr
-
-import (
-	"errors"
-	"fmt"
-	"os"
-	"path"
-	"path/filepath"
-	"strings"
-
-	"git.portale-stac.it/go-pkg/expr/kern"
-	"git.portale-stac.it/go-pkg/expr/util"
-)
-
-const (
-	ENV_EXPR_SOURCE_PATH = "EXPR_PATH"
-	ENV_EXPR_PLUGIN_PATH = "EXPR_PLUGIN_PATH"
-)
-
-func checkStringParamExpected(funcName string, paramValue any, paramPos int) (err error) {
-	if !(kern.IsString(paramValue) /*|| isList(paramValue)*/) {
-		err = fmt.Errorf("%s(): param nr %d has wrong type %s, string expected", funcName, paramPos+1, kern.TypeName(paramValue))
-	}
-	return
-}
-
-// func addSourceEnvImportDirs(varName string, dirList []string) []string {
-// 	return addEnvImportDirs(ENV_EXPR_SOURCE_PATH, dirList)
-// }
-
-// func addPluginEnvImportDirs(varName string, dirList []string) []string {
-// 	return addEnvImportDirs(ENV_EXPR_PLUGIN_PATH, dirList)
-// }
-
-func addEnvImportDirs(envVarName string, dirList []string) []string {
-	if dirSpec, exists := os.LookupEnv(envVarName); exists {
-		dirs := strings.Split(dirSpec, ":")
-		if dirList == nil {
-			dirList = dirs
-		} else {
-			dirList = append(dirList, dirs...)
-		}
-	}
-	return dirList
-}
-
-func addSearchDirs(ctx kern.ExprContext, endingPath string, dirList []string) []string {
-	if dirSpec, exists := getControlString(ctx, kern.ControlSearchPath); exists {
-		dirs := strings.Split(dirSpec, ":")
-		if dirList == nil {
-			dirList = dirs
-		} else {
-			if len(endingPath) > 0 {
-				for _, d := range dirs {
-					dirList = append(dirList, path.Join(d, endingPath))
-				}
-			} else {
-				dirList = append(dirList, dirs...)
-			}
-		}
-	}
-	return dirList
-}
-
-func buildSearchDirList(ctx kern.ExprContext, endingPath, envVarName string) (dirList []string) {
-	dirList = addEnvImportDirs(envVarName, dirList)
-	dirList = addSearchDirs(ctx, endingPath, dirList)
-	return
-}
-
-func isFile(filePath string) bool {
-	info, err := os.Stat(filePath)
-	return (err == nil || errors.Is(err, os.ErrExist)) && info.Mode().IsRegular()
-}
-
-func searchAmongPath(filename string, dirList []string) (filePath string) {
-	var err error
-
-	suffix := SHAREDLIBRARY_EXTENSION
-	if strings.HasSuffix(filename, ".debug") {
-		suffix += ".debug"
-	}
-
-	for _, dir := range dirList {
-		if dir, err = util.ExpandPath(dir); err != nil {
-			continue
-		}
-		if fullPath := path.Join(dir, filename); isFile(fullPath) {
-			filePath = fullPath
-			break
-		}
-
-		subdir := strings.TrimSuffix(filename, suffix)
-		if fullPath := path.Join(dir, subdir, filename); isFile(fullPath) {
-			filePath = fullPath
-			break
-		}
-	}
-	return
-}
-
-func isPathRelative(filePath string) bool {
-	unixPath := filepath.ToSlash(filePath)
-	return strings.HasPrefix(unixPath, "./") || strings.HasPrefix(unixPath, "../")
-}
-
-func makeFilepath(filename string, dirList []string) (filePath string, err error) {
-	if filename, err = util.ExpandPath(filename); err != nil {
-		return
-	}
-
-	if path.IsAbs(filename) || isPathRelative(filename) {
-		if isFile(filename) {
-			filePath = filename
-		}
-	} else {
-		filePath = searchAmongPath(filename, dirList)
-	}
-	if len(filePath) == 0 {
-		err = fmt.Errorf("file %q not found", filename)
-	}
-	return
-}

int-iterator.go

@@ -1,137 +0,0 @@
-// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
-// All rights reserved.
-
-// int-iterator.go
-package expr
-
-import (
-	"fmt"
-	"io"
-	"slices"
-
-	"git.portale-stac.it/go-pkg/expr/kern"
-)
-
-type IntIterator struct {
-	count int64
-	index int64
-	start int64
-	stop  int64
-	step  int64
-}
-
-func NewIntIterator(args []any) (it *IntIterator, err error) {
-	var argc int = 0
-	if args != nil {
-		argc = len(args)
-	}
-	it = &IntIterator{count: 0, index: -1, start: 0, stop: 0, step: 1}
-	if argc >= 1 {
-		if it.stop, err = kern.ToGoInt64(args[0], "start index"); err != nil {
-			return
-		}
-		if argc >= 2 {
-			it.start = it.stop
-			if it.stop, err = kern.ToGoInt64(args[1], "stop index"); err != nil {
-				return
-			}
-			if argc >= 3 {
-				if it.step, err = kern.ToGoInt64(args[2], "step"); err != nil {
-					return
-				}
-			} else if it.start > it.stop {
-				it.step = -1
-			}
-		}
-	}
-	if it.step == 0 {
-		err = fmt.Errorf("step cannot be zero")
-		return
-	}
-	if it.start < it.stop && it.step < 0 {
-		err = fmt.Errorf("step cannot be negative when start < stop")
-		return
-	}
-	if it.start > it.stop && it.step > 0 {
-		err = fmt.Errorf("step cannot be positive when start > stop")
-		return
-	}
-	it.Reset()
-	return
-}
-
-func (it *IntIterator) String() string {
-	return fmt.Sprintf("$(%d..%d..%d)", it.start, it.stop, it.step)
-}
-
-func (it *IntIterator) TypeName() string {
-	return "IntIterator"
-}
-
-func (it *IntIterator) HasOperation(name string) bool {
-	yes := slices.Contains([]string{kern.NextName, kern.ResetName, kern.IndexName, kern.CountName, kern.CurrentName}, name)
-	return yes
-}
-
-func (it *IntIterator) CallOperation(name string, args map[string]any) (v any, err error) {
-	switch name {
-	case kern.NextName:
-		v, err = it.Next()
-	case kern.ResetName:
-		err = it.Reset()
-	case kern.CleanName:
-		err = it.Clean()
-	case kern.IndexName:
-		v = int64(it.Index())
-	case kern.CurrentName:
-		v, err = it.Current()
-	case kern.CountName:
-		v = it.count
-	default:
-		err = kern.ErrNoOperation(name)
-	}
-	return
-}
-
-func (it *IntIterator) Current() (item any, err error) {
-	if it.start <= it.stop {
-		if it.index >= it.start && it.index < it.stop {
-			item = it.index
-		} else {
-			err = io.EOF
-		}
-	} else {
-		if it.index > it.stop && it.index <= it.start {
-			item = it.index
-		} else {
-			err = io.EOF
-		}
-	}
-	return
-}
-
-func (it *IntIterator) Next() (item any, err error) {
-	it.index += it.step
-	if item, err = it.Current(); err != io.EOF {
-		it.count++
-	}
-	return
-}
-
-func (it *IntIterator) Index() int64 {
-	return it.index
-}
-
-func (it *IntIterator) Count() int64 {
-	return it.count
-}
-
-func (it *IntIterator) Reset() error {
-	it.index = it.start - it.step
-	it.count = 0
-	return nil
-}
-
-func (it *IntIterator) Clean() error {
-	return nil
-}

iter-factory.go

@@ -1,29 +0,0 @@
-// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
-// All rights reserved.
-
-// iter-factory.go
-package expr
-
-import (
-	"git.portale-stac.it/go-pkg/expr/kern"
-)
-
-func NewIterator(value any) (it kern.Iterator, err error) {
-	if value == nil {
-		return NewArrayIterator([]any{}), nil
-	}
-
-	switch v := value.(type) {
-	case *kern.ListType:
-		it = NewListIterator(v, nil)
-	case *kern.DictType:
-		it, err = NewDictIterator(v, nil)
-	case []any:
-		it = NewArrayIterator(v)
-	case kern.Iterator:
-		it = v
-	default:
-		it = NewArrayIterator([]any{value})
-	}
-	return
-}

iterator.go

@@ -0,0 +1,40 @@
+// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
+// All rights reserved.
+
+// iterator.go
+package expr
+
+import "io"
+
+type Iterator interface {
+	Reset()
+	Next() (item any, err error) // must return io.EOF after the last item
+	Index() int
+}
+
+type FlatArrayIterator struct {
+	a     []any
+	index int
+}
+
+func NewFlatArrayIterator(array []any) *FlatArrayIterator {
+	return &FlatArrayIterator{a: array, index: 0}
+}
+
+func (it *FlatArrayIterator) Reset() {
+	it.index = 0
+}
+
+func (it *FlatArrayIterator) Next() (item any, err error) {
+	if it.index < len(it.a) {
+		item = it.a[it.index]
+		it.index++
+	} else {
+		err = io.EOF
+	}
+	return
+}
+
+func (it *FlatArrayIterator) Index() int {
+	return it.index - 1
+}

kern/bind-go-functions.go

@@ -1,23 +0,0 @@
-// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
-// All rights reserved.
-
-// bind-go-function.go
-package kern
-
-// ---- Linking with Go functions
-type golangFunctor struct {
-	BaseFunctor
-	f FuncTemplate
-}
-
-func NewGolangFunctor(f FuncTemplate) *golangFunctor {
-	return &golangFunctor{f: f}
-}
-
-func (functor *golangFunctor) TypeName() string {
-	return "GoFunctor"
-}
-
-func (functor *golangFunctor) InvokeNamed(ctx ExprContext, name string, args map[string]any) (result any, err error) {
-	return functor.f(ctx, name, args)
-}

kern/bool.go

@@ -1,27 +0,0 @@
-// Copyright (c) 2024-2026 Celestino Amoroso (celestino.amoroso@gmail.com).
-// All rights reserved.
-
-// string.go
-package kern
-
-func IsBool(v any) (ok bool) {
-	_, ok = v.(bool)
-	return ok
-}
-
-func ToBool(v any) (b bool, ok bool) {
-	ok = true
-	switch x := v.(type) {
-	case string:
-		b = len(x) > 0
-	case float64:
-		b = x != 0.0
-	case int64:
-		b = x != 0
-	case bool:
-		b = x
-	default:
-		ok = false
-	}
-	return
-}

kern/common-errors.go

@@ -1,91 +0,0 @@
-// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
-// All rights reserved.
-
-// common-errors.go
-package kern
-
-import (
-	"fmt"
-	"strings"
-)
-
-func ErrMissingParams(funcName string, missing []string) (err error) {
-	return fmt.Errorf("%s(): missing params -- %s", funcName, strings.Join(missing, ", "))
-}
-
-func ErrTooFewParams(funcName string, minArgs, maxArgs, argCount int) (err error) {
-	if maxArgs < 0 {
-		err = fmt.Errorf("%s(): too few params -- expected %d or more, got %d", funcName, minArgs, argCount)
-	} else {
-		err = fmt.Errorf("%s(): too few params -- expected %d, got %d", funcName, minArgs, argCount)
-	}
-	return
-}
-
-func ErrTooManyParams(funcName string, maxArgs, argCount int) (err error) {
-	err = fmt.Errorf("%s(): too many params -- expected %d, got %d", funcName, maxArgs, argCount)
-	return
-}
-
-// --- General errors
-
-func ErrCantConvert(funcName string, value any, kind string) error {
-	return fmt.Errorf("%s(): can't convert %s to %s", funcName, TypeName(value), kind)
-}
-
-func ErrExpectedGot(funcName string, kind string, value any) error {
-	return fmt.Errorf("%s(): expected %s, got %s (%#v)", funcName, kind, TypeName(value), value)
-}
-
-func ErrFuncDivisionByZero(funcName string) error {
-	return fmt.Errorf("%s(): division by zero", funcName)
-}
-
-// func ErrDivisionByZero() error {
-// 	return fmt.Errorf("division by zero")
-// }
-
-// --- Parameter errors
-
-// func ErrMissingRequiredParameter(funcName, paramName string) error {
-// 	return fmt.Errorf("%s(): missing required parameter %q", funcName, paramName)
-// }
-
-func ErrInvalidParameterValue(funcName, paramName string, paramValue any) error {
-	return fmt.Errorf("%s(): invalid value %s (%#v) for parameter %q", funcName, TypeName(paramValue), paramValue, paramName)
-}
-
-func undefArticle(s string) (article string) {
-	if len(s) > 0 && strings.Contains("aeiou", s[0:1]) {
-		article = "an"
-	} else {
-		article = "a"
-	}
-	return
-}
-
-func prependUndefArticle(s string) (result string) {
-	return undefArticle(s) + " " + s
-}
-
-func ErrWrongParamType(funcName, paramName, paramType string, paramValue any) error {
-	var artWantType, artGotType string
-	gotType := TypeName(paramValue)
-	artGotType = prependUndefArticle(gotType)
-	artWantType = prependUndefArticle(paramType)
-	return fmt.Errorf("%s(): the %q parameter must be %s, got %s (%v)", funcName, paramName, artWantType, artGotType, paramValue)
-}
-
-func ErrUnknownParam(funcName, paramName string) error {
-	return fmt.Errorf("%s(): unknown parameter %q", funcName, paramName)
-}
-
-func ErrUnknownVar(funcName, varName string) error {
-	return fmt.Errorf("%s(): unknown variable %q", funcName, varName)
-}
-
-// --- Operator errors
-
-func ErrLeftOperandMustBeVariable(leftTerm, opTerm Term) error {
-	return leftTerm.Errorf("left operand of %q must be a variable", opTerm.Source())
-}

kern/common-params.go

@@ -1,32 +0,0 @@
-// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
-// All rights reserved.
-
-// common-params.go
-package kern
-
-const (
-	ParamArgs      = "args"
-	ParamCount     = "count"
-	ParamItem      = "item"
-	ParamIndex     = "index"
-	ParamParts     = "parts"
-	ParamSeparator = "separator"
-	ParamSource    = "source"
-	ParamSuffix    = "suffix"
-	ParamPrefix    = "prefix"
-	ParamStart     = "start"
-	ParamEnd       = "end"
-	ParamValue     = "value"
-	ParamName      = "name"
-	ParamEllipsis  = "..."
-	ParamFilepath  = "filepath"
-	ParamDirpath   = "dirpath"
-	ParamHandle    = "handle"
-	ParamResource  = "resource"
-	ParamIterator  = "iterator"
-)
-
-// to be moved in its own source file
-const (
-	ConstLastIndex = 0xFFFF_FFFF
-)

kern/common-type-names.go

@@ -1,23 +0,0 @@
-// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
-// All rights reserved.
-
-// common-type-names.go
-package kern
-
-const (
-	TypeAny           = "any"
-	TypeNil           = "nil"
-	TypeBoolean       = "boolean"
-	TypeFloat         = "float"
-	TypeFraction      = "fraction"
-	TypeFileHandle    = "file-handle"
-	TypeInt           = "integer"
-	TypeItem          = "item"
-	TypeIterator      = "iterator"
-	TypeNumber        = "number"
-	TypePair          = "pair"
-	TypeString        = "string"
-	TypeDict          = "dict"
-	TypeListOf        = "list-of-"
-	TypeListOfStrings = "list-of-strings"
-)

kern/compare.go

@@ -1,37 +0,0 @@
-// Copyright (c) 2024-2026 Celestino Amoroso (celestino.amoroso@gmail.com).
-// All rights reserved.
-
-package kern
-
-import "reflect"
-
-func Equal(value1, value2 any) (equal bool) {
-	if value1 == nil && value2 == nil {
-		equal = true
-	} else if value1 == nil || value2 == nil {
-		equal = false
-	} else if IsBool(value1) && IsBool(value2) {
-		equal = value1.(bool) == value2.(bool)
-	} else if IsList(value1) && IsList(value2) {
-		ls1 := value1.(*ListType)
-		ls2 := value2.(*ListType)
-		equal = ls1.Equals(*ls2)
-	} else if IsDict(value1) && IsDict(value2) {
-		d1 := value1.(*DictType)
-		d2 := value2.(*DictType)
-		equal = d1.Equals(*d2)
-	} else if IsInteger(value1) && IsInteger(value2) {
-		equal = value1.(int64) == value2.(int64)
-	} else if IsString(value1) && IsString(value2) {
-		equal = value1.(string) == value2.(string)
-	} else if IsFloat(value1) && IsFloat(value2) {
-		equal = value1.(float64) == value2.(float64)
-	} else if IsNumOrFract(value1) && IsNumOrFract(value2) {
-		if eq, err := CmpAnyFract(value1, value2); err == nil {
-			equal = eq == 0
-		}
-	} else if !reflect.DeepEqual(value1, value2) {
-		equal = false
-	}
-	return
-}

kern/context-helpers.go

@@ -1,49 +0,0 @@
-// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
-// All rights reserved.
-
-// context-helpers.go
-package kern
-
-func CloneContext(sourceCtx ExprContext) (clonedCtx ExprContext) {
-	if sourceCtx != nil {
-		clonedCtx = sourceCtx.Clone()
-	}
-	return
-}
-
-func exportVar(ctx ExprContext, name string, value any) {
-	if name[0] == '@' {
-		name = name[1:]
-	}
-	ctx.UnsafeSetVar(name, value)
-}
-
-func exportFunc(ctx ExprContext, name string, info ExprFunc) {
-	if name[0] == '@' {
-		name = name[1:]
-	}
-	ctx.RegisterFunc(name, info.Functor(), info.ReturnType(), info.Params())
-}
-
-func ExportObjects(destCtx, sourceCtx ExprContext) {
-	exportAll := CtrlIsEnabled(sourceCtx, ControlExportAll)
-	// fmt.Printf("Exporting from sourceCtx [%p] to destCtx [%p] -- exportAll=%t\n", sourceCtx, destCtx, exportAll)
-	// Export variables
-	for _, refName := range sourceCtx.EnumVars(func(name string) bool { return (exportAll || name[0] == '@') && !(name[0] == '_') }) {
-		// fmt.Printf("\tExporting %q\n", refName)
-		refValue, _ := sourceCtx.GetVar(refName)
-		exportVar(destCtx, refName, refValue)
-	}
-	// Export functions
-	for _, refName := range sourceCtx.EnumFuncs(func(name string) bool { return exportAll || name[0] == '@' }) {
-		if info, _ := sourceCtx.GetFuncInfo(refName); info != nil {
-			exportFunc(destCtx, refName, info)
-		}
-	}
-}
-
-func exportObjectsToParent(sourceCtx ExprContext) {
-	if parentCtx := sourceCtx.GetParent(); parentCtx != nil {
-		ExportObjects(parentCtx, sourceCtx)
-	}
-}

kern/control.go

@@ -1,63 +0,0 @@
-// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
-// All rights reserved.
-
-// control.go
-package kern
-
-import "strings"
-
-// Preset control variables
-const (
-	ControlPreset        = "_preset"
-	ControlLastResult    = "last"
-	ControlBoolShortcut  = "_bool_shortcut"
-	ControlSearchPath    = "_search_path"
-	ControlParentContext = "_parent_context"
-	ControlStdout        = "_stdout"
-)
-
-// Other control variables
-const (
-	ControlExportAll = "_export_all"
-)
-
-// Initial values
-const (
-	init_search_path = "~/.local/lib/go-pkg/expr:/usr/local/lib/go-pkg/expr:/usr/lib/go-pkg/expr"
-)
-
-func CtrlIsEnabled(ctx ExprContext, name string) (status bool) {
-	var v any
-	var exists bool
-
-	if !strings.HasPrefix(name, "_") {
-		name = "_" + name
-	}
-
-	if v, exists = ctx.GetVar(name); !exists {
-		if globalCtx := ctx.GetGlobal(); globalCtx != nil {
-			v, exists = globalCtx.GetVar(name)
-		}
-	}
-
-	if exists {
-		if b, ok := v.(bool); ok {
-			status = b
-		}
-	}
-	return
-}
-func SetCtrl(ctx ExprContext, name string, value any) (current any) {
-	current, _ = ctx.GetVar(name)
-	ctx.UnsafeSetVar(name, value)
-	return
-}
-
-func InitDefaultVars(ctx ExprContext) {
-	if _, exists := ctx.GetVar(ControlPreset); exists {
-		return
-	}
-	ctx.UnsafeSetVar(ControlPreset, true)
-	ctx.UnsafeSetVar(ControlBoolShortcut, true)
-	ctx.UnsafeSetVar(ControlSearchPath, init_search_path)
-}

kern/dict-type.go

@@ -1,193 +0,0 @@
-// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
-// All rights reserved.
-
-// dict-type.go
-package kern
-
-import (
-	"fmt"
-	"reflect"
-	"strings"
-)
-
-type DictType map[any]any
-
-func IsDict(v any) (ok bool) {
-	_, ok = v.(*DictType)
-	return ok
-}
-
-func MakeDict() (dict *DictType) {
-	d := make(DictType)
-	dict = &d
-	return
-}
-
-func NewDict(dictAny map[any]any) (dict *DictType) {
-	var d DictType
-	if dictAny != nil {
-		d = make(DictType, len(dictAny))
-		for i, item := range dictAny {
-			d[i] = item
-		}
-	} else {
-		d = make(DictType)
-	}
-	dict = &d
-	return
-}
-
-func newDict(dictAny map[any]Term) (dict *DictType) {
-	// TODO Change with a call to NewDict()
-	var d DictType
-	if dictAny != nil {
-		d = make(DictType, len(dictAny))
-		for i, item := range dictAny {
-			d[i] = item
-		}
-	} else {
-		d = make(DictType)
-	}
-	dict = &d
-	return
-}
-
-func (dict *DictType) toMultiLine(sb *strings.Builder, opt FmtOpt) {
-	indent := GetFormatIndent(opt)
-	flags := GetFormatFlags(opt)
-	//sb.WriteString(strings.Repeat("  ", indent))
-	sb.WriteByte('{')
-
-	if len(*dict) > 0 {
-		innerOpt := MakeFormatOptions(flags, indent+1)
-		nest := strings.Repeat("  ", indent+1)
-		sb.WriteByte('\n')
-
-		first := true
-		for name, value := range *dict {
-			if first {
-				first = false
-			} else {
-				sb.WriteByte(',')
-				sb.WriteByte('\n')
-			}
-
-			sb.WriteString(nest)
-			if key, ok := name.(string); ok {
-				sb.WriteString(string('"') + key + string('"'))
-			} else {
-				sb.WriteString(fmt.Sprintf("%v", name))
-			}
-			sb.WriteString(": ")
-			if f, ok := value.(Formatter); ok {
-				sb.WriteString(f.ToString(innerOpt))
-			} else if _, ok = value.(Functor); ok {
-				sb.WriteString("func(){}")
-			} else {
-				sb.WriteString(fmt.Sprintf("%v", value))
-			}
-		}
-		sb.WriteByte('\n')
-		sb.WriteString(strings.Repeat("  ", indent))
-	}
-	sb.WriteString("}")
-}
-
-func (dict *DictType) ToString(opt FmtOpt) string {
-	var sb strings.Builder
-	flags := GetFormatFlags(opt)
-	if flags&MultiLine != 0 {
-		dict.toMultiLine(&sb, opt)
-	} else {
-		sb.WriteByte('{')
-		first := true
-		for key, value := range *dict {
-			if first {
-				first = false
-			} else {
-				sb.WriteString(", ")
-			}
-			if s, ok := key.(string); ok {
-				sb.WriteString(string('"') + s + string('"'))
-			} else {
-				sb.WriteString(fmt.Sprintf("%v", key))
-			}
-			sb.WriteString(": ")
-			if formatter, ok := value.(Formatter); ok {
-				sb.WriteString(formatter.ToString(opt))
-			} else if t, ok := value.(Term); ok {
-				sb.WriteString(t.String())
-			} else {
-				sb.WriteString(fmt.Sprintf("%#v", value))
-			}
-		}
-		sb.WriteByte('}')
-	}
-	return sb.String()
-}
-
-func (dict *DictType) String() string {
-	return dict.ToString(0)
-}
-
-func (dict *DictType) TypeName() string {
-	return "dict"
-}
-
-func (dict *DictType) HasKey(target any) (ok bool) {
-	for key := range *dict {
-		if ok = reflect.DeepEqual(key, target); ok {
-			break
-		}
-	}
-	return
-}
-
-func (dict *DictType) SetItem(key any, value any) {
-	(*dict)[key] = value
-}
-
-func (dict *DictType) GetItem(key any) (value any, exists bool) {
-	value, exists = (*dict)[key]
-	return
-}
-
-func (dict *DictType) Clone() (c *DictType) {
-	c = newDict(nil)
-	for k, v := range *dict {
-		(*c)[k] = v
-	}
-	return
-}
-
-func (dict *DictType) Merge(second *DictType) {
-	if second != nil {
-		for k, v := range *second {
-			(*dict)[k] = v
-		}
-	}
-}
-
-func (dict *DictType) Equals(dict2 DictType) (answer bool) {
-	if dict2 != nil && len(*dict) == len(dict2) {
-		answer = true
-		for key, value1 := range *dict {
-			if value2, exists := dict2.GetItem(key); exists {
-				if !Equal(value1, value2) {
-					answer = false
-					break
-				}
-			} else {
-				answer = false
-				break
-			}
-		}
-	}
-	return
-}
-
-////////////////
-
-type DictFormat interface {
-	ToDict() *DictType
-}

kern/expr-context.go

@@ -1,31 +0,0 @@
-// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
-// All rights reserved.
-
-// expr-context.go
-package kern
-
-// ----Expression Context
-type ExprContext interface {
-	Clone() ExprContext
-	SetParent(ctx ExprContext)
-	GetParent() (ctx ExprContext)
-	GetGlobal() (ctx ExprContext)
-	GetVar(varName string) (value any, exists bool)
-	GetLast() any
-	SetVar(varName string, value any)
-	UnsafeSetVar(varName string, value any)
-
-	EnumVars(func(name string) (accept bool)) (varNames []string)
-	VarCount() int
-	DeleteVar(varName string)
-
-	EnumFuncs(func(name string) (accept bool)) (funcNames []string)
-	FuncCount() int
-	DeleteFunc(funcName string)
-
-	GetLocalFuncInfo(name string) (info ExprFunc, exists bool)
-	GetFuncInfo(name string) (item ExprFunc, exists bool)
-	Call(name string, args map[string]any) (result any, err error)
-	RegisterFuncInfo(info ExprFunc)
-	RegisterFunc(name string, f Functor, returnType string, param []ExprFuncParam) (funcInfo ExprFunc, err error)
-}

kern/expr-function.go

@@ -1,39 +0,0 @@
-// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
-// All rights reserved.
-
-// expr-function.go
-package kern
-
-// ---- Functor interface
-type Functor interface {
-	Typer
-	InvokeNamed(ctx ExprContext, name string, args map[string]any) (result any, err error)
-	SetFunc(info ExprFunc)
-	GetFunc() ExprFunc
-	GetParams() []ExprFuncParam
-	GetDefinitionContext() ExprContext
-}
-
-// ---- Function Param Info
-type ExprFuncParam interface {
-	Name() string
-	Type() string
-	IsDefault() bool
-	IsOptional() bool
-	IsRepeat() bool
-	DefaultValue() any
-}
-
-// ---- Function Info
-type ExprFunc interface {
-	Formatter
-	Name() string
-	MinArgs() int
-	MaxArgs() int
-	Functor() Functor
-	Params() []ExprFuncParam
-	ParamSpec(paramName string) ExprFuncParam
-	ReturnType() string
-	PrepareCall(name string, actualParams map[string]any) (err error)
-	AllocContext(parentCtx ExprContext) (ctx ExprContext)
-}

kern/float.go

@@ -1,23 +0,0 @@
-// Copyright (c) 2024-2026 Celestino Amoroso (celestino.amoroso@gmail.com).
-// All rights reserved.
-
-// float.go
-package kern
-
-func IsFloat(v any) (ok bool) {
-	_, ok = v.(float64)
-	return ok
-}
-
-func AnyFloat(v any) (float float64, ok bool) {
-	ok = true
-	switch floatval := v.(type) {
-	case float32:
-		float = float64(floatval)
-	case float64:
-		float = floatval
-	default:
-		ok = false
-	}
-	return
-}

kern/formatter.go

@@ -1,79 +0,0 @@
-// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
-// All rights reserved.
-
-// formatter.go
-package kern
-
-import "fmt"
-
-type FmtOpt uint32 // lower 16 bits hold a bit-mask, higher 16 bits hold an indentation number
-
-const (
-	TTY FmtOpt = 1 << iota
-	MultiLine
-	Truncate
-	Base2
-	Base8
-	Base10
-	Base16
-)
-
-const (
-	TruncateEllipsis = "(...)"
-	MinTruncateSize  = 10
-	TruncateSize     = MinTruncateSize + 15
-)
-
-func TruncateString(s string) (trunc string) {
-	finalPart := len(s) - (MinTruncateSize - len(TruncateEllipsis))
-	trunc = s[0:len(s)-MinTruncateSize] + TruncateEllipsis + s[finalPart:]
-	return
-}
-
-func MakeFormatOptions(flags FmtOpt, indent int) FmtOpt {
-	return FmtOpt(indent<<16) | flags
-}
-
-func GetFormatFlags(opt FmtOpt) FmtOpt {
-	return opt & 0xFFFF
-}
-
-func GetFormatIndent(opt FmtOpt) int {
-	return int(opt >> 16)
-}
-
-type Formatter interface {
-	ToString(options FmtOpt) string
-}
-
-func GetFormatted(v any, opt FmtOpt) (text string) {
-	if v == nil {
-		text = "(nil)"
-	} else if s, ok := v.(string); ok {
-		text = s
-	} else if formatter, ok := v.(Formatter); ok {
-		text = formatter.ToString(opt)
-	} else {
-		text = fmt.Sprintf("%v", v)
-	}
-	return
-}
-
-type Typer interface {
-	TypeName() string
-}
-
-func TypeName(v any) (name string) {
-	if v == nil {
-		name = "nil"
-	} else if typer, ok := v.(Typer); ok {
-		name = typer.TypeName()
-	} else if IsInteger(v) {
-		name = "integer"
-	} else if IsFloat(v) {
-		name = "float"
-	} else {
-		name = fmt.Sprintf("%T", v)
-	}
-	return
-}

kern/fraction-type.go

@@ -1,384 +0,0 @@
-// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
-// All rights reserved.
-
-// fraction-type.go
-package kern
-
-//https://www.youmath.it/lezioni/algebra-elementare/lezioni-di-algebra-e-aritmetica-per-scuole-medie/553-dalle-frazioni-a-numeri-decimali.html
-
-import (
-	"errors"
-	"fmt"
-	"math"
-	"strconv"
-	"strings"
-)
-
-type FractionType struct {
-	num, den int64
-}
-
-func NewFraction(num, den int64) *FractionType {
-	num, den = simplifyIntegers(num, den)
-	return &FractionType{num, den}
-}
-
-func Float64ToFraction(f float64) (fract *FractionType, err error) {
-	var sign string
-	intPart, decPart := math.Modf(f)
-	if decPart < 0.0 {
-		sign = "-"
-		intPart = -intPart
-		decPart = -decPart
-	}
-	dec := fmt.Sprintf("%.12f", decPart)
-	s := fmt.Sprintf("%s%.f%s", sign, intPart, dec[1:])
-	return MakeGeneratingFraction(s)
-}
-
-// Based on https://cs.opensource.google/go/go/+/refs/tags/go1.22.3:src/math/big/rat.go;l=39
-func MakeGeneratingFraction(s string) (f *FractionType, err error) {
-	var num, den int64
-	var sign int64 = 1
-	var parts []string
-	if len(s) == 0 {
-		goto exit
-	}
-	if s[0] == '-' {
-		sign = int64(-1)
-		s = s[1:]
-	} else if s[0] == '+' {
-		s = s[1:]
-	}
-	//	if strings.HasSuffix(s, "()") {
-	//		s = s[0 : len(s)-2]
-	//	}
-	s = strings.TrimSuffix(s, "()")
-	parts = strings.SplitN(s, ".", 2)
-	if num, err = strconv.ParseInt(parts[0], 10, 64); err != nil {
-		return
-	}
-	if len(parts) == 1 {
-		f = NewFraction(sign*num, 1)
-	} else if len(parts) == 2 {
-		subParts := strings.SplitN(parts[1], "(", 2)
-		if len(subParts) == 1 {
-			den = 1
-			dec := parts[1]
-			lsd := len(dec)
-			for i := lsd - 1; i >= 0 && dec[i] == '0'; i-- {
-				lsd--
-			}
-			for _, c := range dec[0:lsd] {
-				if c < '0' || c > '9' {
-					return nil, ErrExpectedGot("fract", "digit", c)
-				}
-				num = num*10 + int64(c-'0')
-				den = den * 10
-			}
-			f = NewFraction(sign*num, den)
-		} else if len(subParts) == 2 {
-			sub := num
-			mul := int64(1)
-			for _, c := range subParts[0] {
-				if c < '0' || c > '9' {
-					return nil, ErrExpectedGot("fract", "digit", c)
-				}
-				num = num*10 + int64(c-'0')
-				sub = sub*10 + int64(c-'0')
-				mul *= 10
-			}
-			if len(subParts) == 2 {
-				if s[len(s)-1] != ')' {
-					goto exit
-				}
-				p := subParts[1][0 : len(subParts[1])-1]
-				for _, c := range p {
-					if c < '0' || c > '9' {
-						return nil, ErrExpectedGot("fract", "digit", c)
-					}
-					num = num*10 + int64(c-'0')
-					den = den*10 + 9
-				}
-				den *= mul
-			}
-			num -= sub
-			f = NewFraction(sign*num, den)
-		}
-	}
-exit:
-	if f == nil {
-		err = errors.New("bad syntax")
-	}
-	return
-}
-
-func (f *FractionType) N() int64 {
-	return f.num
-}
-
-func (f *FractionType) D() int64 {
-	return f.den
-}
-
-func (f *FractionType) ToFloat() float64 {
-	return float64(f.num) / float64(f.den)
-}
-
-func (f *FractionType) String() string {
-	return f.ToString(0)
-}
-
-func (f *FractionType) ToString(opt FmtOpt) string {
-	var sb strings.Builder
-	if opt&MultiLine == 0 {
-		sb.WriteString(fmt.Sprintf("%d:%d", f.num, f.den))
-	} else {
-		var sign, num string
-		if f.num < 0 && opt&TTY == 0 {
-			num = strconv.FormatInt(-f.num, 10)
-			sign = "-"
-		} else {
-			num = strconv.FormatInt(f.num, 10)
-		}
-		den := strconv.FormatInt(f.den, 10)
-		size := max(len(num), len(den))
-		if opt&TTY != 0 {
-			sNum := fmt.Sprintf("\x1b[4m%[1]*s\x1b[0m\n", -size, fmt.Sprintf("%[1]*s", (size+len(num))/2, sign+num))
-			sb.WriteString(sNum)
-		} else {
-			if len(sign) > 0 {
-				sb.WriteString("  ")
-			}
-			sb.WriteString(fmt.Sprintf("%[1]*s", -size, fmt.Sprintf("%[1]*s", (size+len(num))/2, num)))
-			sb.WriteByte('\n')
-			if len(sign) > 0 {
-				sb.WriteString(sign)
-				sb.WriteByte(' ')
-			}
-			sb.WriteString(strings.Repeat("-", size))
-			sb.WriteByte('\n')
-			if len(sign) > 0 {
-				sb.WriteString("  ")
-			}
-		}
-		sDen := fmt.Sprintf("%[1]*s", size, fmt.Sprintf("%[1]*s", (size+len(den))/2, den))
-		sb.WriteString(sDen)
-	}
-
-	return sb.String()
-}
-
-func (f *FractionType) TypeName() string {
-	return "fraction"
-}
-
-// -------- fraction utility functions
-
-// greatest common divider
-func Gcd(a, b int64) (g int64) {
-	if a < 0 {
-		a = -a
-	}
-	if b < 0 {
-		b = -b
-	}
-	if a < b {
-		a, b = b, a
-	}
-	r := a % b
-	for r > 0 {
-		a, b = b, r
-		r = a % b
-	}
-	g = b
-	return
-}
-
-// lower common multiple
-func lcm(a, b int64) (l int64) {
-	g := Gcd(a, b)
-	l = a * b / g
-	return
-}
-
-// Sum two fractions
-func SumFract(f1, f2 *FractionType) (sum *FractionType) {
-	m := lcm(f1.den, f2.den)
-	sum = NewFraction(f1.num*(m/f1.den)+f2.num*(m/f2.den), m)
-	return
-}
-
-// Multiply two fractions
-func MulFract(f1, f2 *FractionType) (prod *FractionType) {
-	prod = NewFraction(f1.num*f2.num, f1.den*f2.den)
-	return
-}
-
-func anyToFract(v any) (f *FractionType, err error) {
-	var ok bool
-	if f, ok = v.(*FractionType); !ok {
-		if n, ok := v.(int64); ok {
-			f = intToFraction(n)
-		} else if dec, ok := v.(float64); ok {
-			f, err = Float64ToFraction(dec)
-		} else {
-			err = ErrExpectedGot("fract", TypeFraction, v)
-		}
-	}
-	return
-}
-
-func anyPairToFract(v1, v2 any) (f1, f2 *FractionType, err error) {
-	if f1, err = anyToFract(v1); err != nil {
-		return
-	}
-	if f2, err = anyToFract(v2); err != nil {
-		return
-	}
-	return
-}
-
-func SumAnyFract(af1, af2 any) (sum any, err error) {
-	var f1, f2 *FractionType
-	if f1, f2, err = anyPairToFract(af1, af2); err != nil {
-		return
-	}
-	f := SumFract(f1, f2)
-	if f.num == 0 {
-		sum = 0
-	} else {
-		sum = simplifyFraction(f)
-	}
-	return
-}
-
-// Returns
-//
-//		 <0 if af1 < af2
-//		 =0 if af1 == af2
-//		 >0 if af1 > af2
-//	 err if af1 or af2 is not convertible to fraction
-func CmpAnyFract(af1, af2 any) (result int, err error) {
-	var f1, f2 *FractionType
-	if f1, f2, err = anyPairToFract(af1, af2); err != nil {
-		return
-	}
-	result = cmpFract(f1, f2)
-	return
-}
-
-// Returns
-//
-//	<0 if af1 < af2
-//	=0 if af1 == af2
-//	>0 if af1 > af2
-func cmpFract(f1, f2 *FractionType) (result int) {
-	if f1 != nil && f2 != nil {
-		f2.num = -f2.num
-		f := SumFract(f1, f2)
-		if f.num < 0 {
-			result = -1
-		} else if f.num > 0 {
-			result = 1
-		} else {
-			result = 0
-		}
-	}
-	return
-}
-
-func SubAnyFract(af1, af2 any) (sum any, err error) {
-	var f1, f2 *FractionType
-	if f1, f2, err = anyPairToFract(af1, af2); err != nil {
-		return
-	}
-	f2.num = -f2.num
-	f := SumFract(f1, f2)
-	if f.num == 0 {
-		sum = 0
-	} else {
-		sum = simplifyFraction(f)
-	}
-	return
-}
-
-func MulAnyFract(af1, af2 any) (prod any, err error) {
-	var f1, f2 *FractionType
-	if f1, f2, err = anyPairToFract(af1, af2); err != nil {
-		return
-	}
-	if f1.num == 0 || f2.num == 0 {
-		prod = 0
-	} else {
-		f := &FractionType{f1.num * f2.num, f1.den * f2.den}
-		prod = simplifyFraction(f)
-	}
-	return
-}
-
-func DivAnyFract(af1, af2 any) (quot any, err error) {
-	var f1, f2 *FractionType
-	if f1, f2, err = anyPairToFract(af1, af2); err != nil {
-		return
-	}
-	if f2.num == 0 {
-		err = errors.New("division by zero")
-		return
-	}
-	if f1.num == 0 || f2.den == 0 {
-		quot = 0
-	} else {
-		f := &FractionType{f1.num * f2.den, f1.den * f2.num}
-		quot = simplifyFraction(f)
-	}
-	return
-}
-
-func simplifyFraction(f *FractionType) (v any) {
-	f.num, f.den = simplifyIntegers(f.num, f.den)
-	if f.den == 1 {
-		v = f.num
-	} else {
-		v = &FractionType{f.num, f.den}
-	}
-	return v
-}
-
-func simplifyIntegers(num, den int64) (a, b int64) {
-	if num == 0 {
-		return 0, 1
-	}
-	if den == 0 {
-		panic("fraction with denominator == 0")
-	}
-	if den < 0 {
-		den = -den
-		num = -num
-	}
-	g := Gcd(num, den)
-	a = num / g
-	b = den / g
-	return
-}
-
-func intToFraction(n int64) *FractionType {
-	return &FractionType{n, 1}
-}
-
-func IsFraction(v any) (ok bool) {
-	_, ok = v.(*FractionType)
-	return ok
-}
-
-// func IsFract(v any) (ok bool) {
-// 	_, ok = v.(*FractionType)
-// 	return ok
-// }
-
-func IsRational(v any) (ok bool) {
-	if _, ok = v.(*FractionType); !ok {
-		_, ok = v.(int64)
-	}
-	return ok
-}

kern/function.go

@@ -1,278 +0,0 @@
-// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
-// All rights reserved.
-
-// function.go
-package kern
-
-import (
-	"fmt"
-	"strconv"
-)
-
-// ---- Function templates
-type FuncTemplate func(ctx ExprContext, name string, args map[string]any) (result any, err error)
-
-type DeepFuncTemplate func(a, b any) (eq bool, err error)
-
-func IsFunctor(v any) (ok bool) {
-	_, ok = v.(Functor)
-	return
-}
-
-// ---- Common functor definition
-type BaseFunctor struct {
-	info ExprFunc
-}
-
-func (functor *BaseFunctor) ToString(opt FmtOpt) (s string) {
-	if functor.info != nil {
-		s = functor.info.ToString(opt)
-	} else {
-		s = "func(){}"
-	}
-	return s
-}
-
-func (functor *BaseFunctor) GetParams() (params []ExprFuncParam) {
-	if functor.info != nil {
-		return functor.info.Params()
-	} else {
-		return []ExprFuncParam{}
-	}
-}
-
-func (functor *BaseFunctor) SetFunc(info ExprFunc) {
-	functor.info = info
-}
-
-func (functor *BaseFunctor) GetFunc() ExprFunc {
-	return functor.info
-}
-
-func (functor *BaseFunctor) GetDefinitionContext() ExprContext {
-	return nil
-}
-
-// ---- Function Parameters
-type paramFlags uint16
-
-const (
-	PfDefault paramFlags = 1 << iota
-	PfOptional
-	PfRepeat
-)
-
-type funcParamInfo struct {
-	name         string
-	flags        paramFlags
-	defaultValue any
-}
-
-func NewFuncParam(name string) ExprFuncParam {
-	return &funcParamInfo{name: name}
-}
-
-func NewFuncParamFlag(name string, flags paramFlags) ExprFuncParam {
-	return &funcParamInfo{name: name, flags: flags}
-}
-
-func NewFuncParamFlagDef(name string, flags paramFlags, defValue any) *funcParamInfo {
-	return &funcParamInfo{name: name, flags: flags, defaultValue: defValue}
-}
-
-func (param *funcParamInfo) Name() string {
-	return param.name
-}
-
-func (param *funcParamInfo) Type() string {
-	return TypeAny
-}
-
-func (param *funcParamInfo) IsDefault() bool {
-	return (param.flags & PfDefault) != 0
-}
-
-func (param *funcParamInfo) IsOptional() bool {
-	return (param.flags & PfOptional) != 0
-}
-
-func (param *funcParamInfo) IsRepeat() bool {
-	return (param.flags & PfRepeat) != 0
-}
-
-func (param *funcParamInfo) DefaultValue() any {
-	return param.defaultValue
-}
-
-func initActualParams(ctx ExprContext, info ExprFunc, callTerm Term) (actualParams map[string]any, err error) {
-	var varArgs []any
-	var varName string
-
-	namedParamsStarted := false
-
-	formalParams := info.Params()
-	actualParams = make(map[string]any, len(formalParams))
-	if callTerm == nil {
-		return
-	}
-
-	childCount := callTerm.GetChildCount()
-	for i := range childCount {
-		tree := callTerm.GetChild(i)
-		// for i, tree := range callTerm.Children() {
-		var paramValue any
-		paramCtx := ctx.Clone()
-		if paramValue, err = tree.Compute(paramCtx); err != nil {
-			break
-		}
-		if paramName, namedParam := GetAssignVarName(tree); namedParam {
-			if info.ParamSpec(paramName) == nil {
-				err = fmt.Errorf("%s(): unknown param %q", info.Name(), paramName)
-				break
-			}
-			actualParams[paramName] = paramValue
-			namedParamsStarted = true
-		} else if !namedParamsStarted {
-			if varArgs != nil {
-				varArgs = append(varArgs, paramValue)
-			} else if i < len(formalParams) {
-				spec := formalParams[i]
-				if spec.IsRepeat() {
-					varArgs = make([]any, 0, childCount-i)
-					varArgs = append(varArgs, paramValue)
-					varName = spec.Name()
-				} else {
-					actualParams[spec.Name()] = paramValue
-				}
-			} else {
-				err = ErrTooManyParams(info.Name(), len(formalParams), childCount)
-				break
-			}
-		} else {
-			err = fmt.Errorf("%s(): positional param nr %d not allowed after named params", info.Name(), i+1)
-			break
-		}
-	}
-	if err == nil {
-		if varArgs != nil {
-			actualParams[varName] = varArgs
-		}
-	}
-	return
-}
-
-// func (info *funcInfo) PrepareCall(name string, actualParams map[string]any) (err error) {
-// 	passedCount := len(actualParams)
-// 	if info.MinArgs() > passedCount {
-// 		err = ErrTooFewParams(name, info.MinArgs(), info.MaxArgs(), passedCount)
-// 		return
-// 	}
-
-// 	if passedCount < len(info.formalParams) {
-// 		for _, p := range info.formalParams {
-// 			if _, exists := actualParams[p.Name()]; !exists {
-// 				if !p.IsDefault() {
-// 					break
-// 				}
-// 				if p.IsRepeat() {
-// 					varArgs := make([]any, 1)
-// 					varArgs[0] = p.DefaultValue()
-// 					actualParams[p.Name()] = varArgs
-// 				} else {
-// 					actualParams[p.Name()] = p.DefaultValue()
-// 				}
-// 			}
-// 		}
-// 	}
-
-// 	if info.MaxArgs() >= 0 && info.MaxArgs() < len(actualParams) {
-// 		err = ErrTooManyParams(name, info.MaxArgs(), len(actualParams))
-// 	}
-// 	return
-// }
-
-// ----- Call a function ---
-
-// func getAssignVarName(t *term) (name string, ok bool) {
-// 	if ok = t.symbol() == SymEqual; ok {
-// 		name = t.children[0].source()
-// 	}
-// 	return
-// }
-
-func GetAssignVarName(t Term) (name string, ok bool) {
-	if ok = t.IsAssign(); ok {
-		name = t.GetChildSource(0)
-	}
-	return
-}
-
-func CallFunctionByTerm(parentCtx ExprContext, name string, callTerm Term) (result any, err error) {
-	var actualParams map[string]any
-	if info, exists := parentCtx.GetFuncInfo(name); exists {
-		if actualParams, err = initActualParams(parentCtx, info, callTerm); err == nil {
-			ctx := info.AllocContext(parentCtx)
-			if err = info.PrepareCall(name, actualParams); err == nil {
-				functor := info.Functor()
-				result, err = functor.InvokeNamed(ctx, name, actualParams)
-				exportObjectsToParent(ctx)
-			}
-		}
-	} else {
-		err = fmt.Errorf("unknown function %s()", name)
-	}
-	return
-}
-
-func CallFunctionByArgs(parentCtx ExprContext, name string, args []any) (result any, err error) {
-	var actualParams map[string]any
-	if info, exists := parentCtx.GetFuncInfo(name); exists {
-		functor := info.Functor()
-		actualParams = BindActualParams(functor, args)
-		ctx := info.AllocContext(parentCtx)
-		if err = info.PrepareCall(name, actualParams); err == nil {
-			result, err = functor.InvokeNamed(ctx, name, actualParams)
-			exportObjectsToParent(ctx)
-		}
-	} else {
-		err = fmt.Errorf("unknown function %s()", name)
-	}
-	return
-}
-
-func CallFunctionByParams(parentCtx ExprContext, name string, actualParams map[string]any) (result any, err error) {
-	//var actualParams map[string]any
-	if info, exists := parentCtx.GetFuncInfo(name); exists {
-		functor := info.Functor()
-		ctx := info.AllocContext(parentCtx)
-		if err = info.PrepareCall(name, actualParams); err == nil {
-			result, err = functor.InvokeNamed(ctx, name, actualParams)
-			exportObjectsToParent(ctx)
-		}
-	} else {
-		err = fmt.Errorf("unknown function %s()", name)
-	}
-	return
-}
-
-func GetParam(args map[string]any, paramName string, paramNum int) (value any, exists bool) {
-	if value, exists = args[paramName]; !exists {
-		if paramNum > 0 && paramNum <= len(args) {
-			value, exists = args["arg"+strconv.Itoa(paramNum)]
-		}
-	}
-	return
-}
-
-func BindActualParams(functor Functor, args []any) (actualParams map[string]any) {
-	formalParams := functor.GetParams()
-	actualParams = make(map[string]any, len(args))
-	for i, arg := range args {
-		if i < len(formalParams) {
-			actualParams[formalParams[i].Name()] = arg
-		} else {
-			actualParams["arg"+strconv.Itoa(i+1)] = arg
-		}
-	}
-	return
-}

kern/iterator.go

@@ -1,52 +0,0 @@
-// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
-// All rights reserved.
-
-// iterator.go
-package kern
-
-import (
-	// "errors"
-	"fmt"
-)
-
-// Operator names
-
-const (
-	InitName    = "init"
-	CleanName   = "clean"
-	ResetName   = "reset"
-	NextName    = "next"
-	CurrentName = "current"
-	IndexName   = "index"
-	CountName   = "count"
-	FilterName  = "filter"
-	MapName     = "map"
-	KeyName     = "key"
-	ValueName   = "value"
-)
-
-type Iterator interface {
-	Typer
-	fmt.Stringer
-	Next() (item any, err error) // must return io.EOF after the last item
-	Current() (item any, err error)
-	Index() int64
-	Count() int64
-	HasOperation(name string) bool
-	CallOperation(name string, args map[string]any) (value any, err error)
-}
-
-type ExtIterator interface {
-	Iterator
-	Reset() error
-	Clean() error
-}
-
-func ErrNoOperation(name string) error {
-	return fmt.Errorf("no %s() function defined in the data-source", name)
-}
-
-func IsIterator(v any) (ok bool) {
-	_, ok = v.(Iterator)
-	return
-}

kern/list-type.go

@@ -1,202 +0,0 @@
-// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
-// All rights reserved.
-
-// list-type.go
-package kern
-
-import (
-	"fmt"
-	"reflect"
-	"strings"
-)
-
-type ListType []any
-
-func IsList(v any) (ok bool) {
-	_, ok = v.(*ListType)
-	return ok
-}
-
-func NewListA(listAny ...any) (list *ListType) {
-	if listAny == nil {
-		listAny = []any{}
-	}
-	return NewList(listAny)
-}
-
-func NewList(listAny []any) (list *ListType) {
-	if listAny != nil {
-		ls := make(ListType, len(listAny))
-		copy(ls, listAny)
-		list = &ls
-	}
-	return
-}
-
-func MakeList(length, capacity int) (list *ListType) {
-	if capacity < length {
-		capacity = length
-	}
-	ls := make(ListType, length, capacity)
-	list = &ls
-	return
-}
-
-func ListFromStrings(stringList []string) (list *ListType) {
-	list = MakeList(len(stringList), 0)
-	for i, s := range stringList {
-		(*list)[i] = s
-	}
-	return
-}
-
-func (dict *ListType) ToString(opt FmtOpt) (s string) {
-	indent := GetFormatIndent(opt)
-	flags := GetFormatFlags(opt)
-
-	var sb strings.Builder
-	sb.WriteByte('[')
-	if len(*dict) > 0 {
-		innerOpt := MakeFormatOptions(flags, indent+1)
-		nest := strings.Repeat("  ", indent+1)
-
-		if flags&MultiLine != 0 {
-			sb.WriteByte('\n')
-			sb.WriteString(nest)
-		}
-		for i, item := range []any(*dict) {
-			if i > 0 {
-				if flags&MultiLine != 0 {
-					sb.WriteString(",\n")
-					sb.WriteString(nest)
-				} else {
-					sb.WriteString(", ")
-				}
-			}
-			if s, ok := item.(string); ok {
-				sb.WriteByte('"')
-				sb.WriteString(s)
-				sb.WriteByte('"')
-			} else if formatter, ok := item.(Formatter); ok {
-				sb.WriteString(formatter.ToString(innerOpt))
-			} else {
-				sb.WriteString(fmt.Sprintf("%v", item))
-			}
-		}
-		if flags&MultiLine != 0 {
-			sb.WriteByte('\n')
-			sb.WriteString(strings.Repeat("  ", indent))
-		}
-	}
-	sb.WriteByte(']')
-	s = sb.String()
-	if flags&Truncate != 0 && len(s) > TruncateSize {
-		s = TruncateString(s)
-	}
-	return
-}
-
-func (dict *ListType) String() string {
-	return dict.ToString(0)
-}
-
-func (dict *ListType) TypeName() string {
-	return "list"
-}
-
-func (dict *ListType) Contains(t *ListType) (answer bool) {
-	if len(*dict) >= len(*t) {
-		answer = true
-		for _, item := range *t {
-			if answer = dict.IndexDeepSameCmp(item) >= 0; !answer {
-				break
-			}
-		}
-	}
-	return
-}
-
-func (ls1 *ListType) Equals(ls2 ListType) (answer bool) {
-	if ls2 != nil && len(*ls1) == len(ls2) {
-		answer = true
-		for index, i1 := range *ls1 {
-			// if !reflect.DeepEqual(i1, ls2[index]) {
-			// 	answer = false
-			// 	break
-			// }
-			if !Equal(i1, ls2[index]) {
-				answer = false
-				break
-			}
-		}
-	}
-	return
-}
-
-func (dict *ListType) IndexDeepSameCmp(target any) (index int) {
-	var eq bool
-	var err error
-	index = -1
-	for i, item := range *dict {
-		if eq, err = deepSame(item, target, SameContent); err != nil {
-			break
-		} else if eq {
-			index = i
-			break
-		}
-	}
-	return
-}
-
-func SameContent(a, b any) (same bool, err error) {
-	la, _ := a.(*ListType)
-	lb, _ := b.(*ListType)
-	if len(*la) == len(*lb) {
-		same = true
-		for _, item := range *la {
-			if pos := lb.IndexDeepSameCmp(item); pos < 0 {
-				same = false
-				break
-			}
-		}
-	}
-	return
-}
-
-func deepSame(a, b any, deepCmp DeepFuncTemplate) (eq bool, err error) {
-	if IsNumOrFract(a) && IsNumOrFract(b) {
-		if IsNumber(a) && IsNumber(b) {
-			if IsInteger(a) && IsInteger(b) {
-				li, _ := a.(int64)
-				ri, _ := b.(int64)
-				eq = li == ri
-			} else {
-				eq = NumAsFloat(a) == NumAsFloat(b)
-			}
-		} else {
-			var cmp int
-			if cmp, err = CmpAnyFract(a, b); err == nil {
-				eq = cmp == 0
-			}
-		}
-	} else if deepCmp != nil && IsList(a) && IsList(b) {
-		eq, err = deepCmp(a, b)
-	} else {
-		eq = reflect.DeepEqual(a, b)
-	}
-
-	return
-}
-
-func (dict *ListType) SetItem(index int64, value any) (err error) {
-	if index >= 0 && index < int64(len(*dict)) {
-		(*dict)[index] = value
-	} else {
-		err = fmt.Errorf("index %d out of bounds (0, %d)", index, len(*dict)-1)
-	}
-	return
-}
-
-func (dict *ListType) AppendItem(value any) {
-	*dict = append(*dict, value)
-}

kern/number.go

@@ -1,88 +0,0 @@
-// Copyright (c) 2024-2026 Celestino Amoroso (celestino.amoroso@gmail.com).
-// All rights reserved.
-
-// number.go
-package kern
-
-import (
-	"fmt"
-)
-
-func IsInteger(v any) (ok bool) {
-	_, ok = v.(int64)
-	return ok
-}
-
-func IsNumber(v any) (ok bool) {
-	return IsFloat(v) || IsInteger(v)
-}
-
-func IsNumOrFract(v any) (ok bool) {
-	return IsFloat(v) || IsInteger(v) || IsFraction(v)
-}
-
-func IsNumberString(v any) (ok bool) {
-	return IsString(v) || IsNumber(v)
-}
-
-func NumAsFloat(v any) (f float64) {
-	var ok bool
-	if f, ok = v.(float64); !ok {
-		if fract, ok := v.(*FractionType); ok {
-			f = fract.ToFloat()
-		} else {
-			i, _ := v.(int64)
-			f = float64(i)
-		}
-	}
-	return
-}
-
-func AnyInteger(v any) (i int64, ok bool) {
-	ok = true
-	switch intval := v.(type) {
-	case int:
-		i = int64(intval)
-	case uint8:
-		i = int64(intval)
-	case uint16:
-		i = int64(intval)
-	case uint64:
-		i = int64(intval)
-	case uint32:
-		i = int64(intval)
-	case int8:
-		i = int64(intval)
-	case int16:
-		i = int64(intval)
-	case int32:
-		i = int64(intval)
-	case int64:
-		i = intval
-	default:
-		ok = false
-	}
-	return
-}
-
-func ToGoInt(value any, description string) (i int, err error) {
-	if valueInt64, ok := value.(int64); ok {
-		i = int(valueInt64)
-	} else if valueInt, ok := value.(int); ok {
-		i = valueInt
-	} else {
-		err = fmt.Errorf("%s expected integer, got %s (%v)", description, TypeName(value), value)
-	}
-	return
-}
-
-func ToGoInt64(value any, description string) (i int64, err error) {
-	if valueInt64, ok := value.(int64); ok {
-		i = valueInt64
-	} else if valueInt, ok := value.(int); ok {
-		i = int64(valueInt)
-	} else {
-		err = fmt.Errorf("%s expected integer, got %s (%v)", description, TypeName(value), value)
-	}
-	return
-}

kern/string.go

@@ -1,23 +0,0 @@
-// Copyright (c) 2024-2026 Celestino Amoroso (celestino.amoroso@gmail.com).
-// All rights reserved.
-
-// string.go
-package kern
-
-import (
-	"fmt"
-)
-
-func IsString(v any) (ok bool) {
-	_, ok = v.(string)
-	return ok
-}
-
-func ToGoString(value any, description string) (s string, err error) {
-	if s, ok := value.(string); ok {
-		return s, nil
-	} else {
-		err = fmt.Errorf("%s expected string, got %s (%v)", description, TypeName(value), value)
-	}
-	return
-}

kern/term.go

@@ -1,21 +0,0 @@
-// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
-// All rights reserved.
-
-// term.go
-package kern
-
-import (
-	"fmt"
-)
-
-type Term interface {
-	fmt.Stringer
-	// Children() []Term
-	Source() string
-	GetChildCount() (count int)
-	GetChild(index int) Term
-	GetChildSource(index int) string
-	Compute(ctx ExprContext) (result any, err error)
-	IsAssign() bool
-	Errorf(template string, args ...any) (err error)
-}

lib-ext-darwin.go

@@ -1,9 +0,0 @@
-//go:build darwin
-
-// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
-// All rights reserved.
-
-// lib-ext-darwin.go
-package expr
-
-const SHAREDLIBRARY_EXTENSION = ".dylib"

lib-ext-linux.go

@@ -1,9 +0,0 @@
-//go:build linux
-
-// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
-// All rights reserved.
-
-// lib-ext-linux.go
-package expr
-
-const SHAREDLIBRARY_EXTENSION = ".so"

lib-ext-windows.go

@@ -1,9 +0,0 @@
-//go:build windows
-
-// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
-// All rights reserved.
-
-// lib-ext-windows.go
-package expr
-
-const SHAREDLIBRARY_EXTENSION = ".dll"

list-iterator.go

@@ -1,149 +0,0 @@
-// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
-// All rights reserved.
-
-// list-iterator.go
-package expr
-
-import (
-	"fmt"
-	"io"
-	"slices"
-
-	"git.portale-stac.it/go-pkg/expr/kern"
-)
-
-type ListIterator struct {
-	a     *kern.ListType
-	count int64
-	index int64
-	start int64
-	stop  int64
-	step  int64
-}
-
-func NewListIterator(list *kern.ListType, args []any) (it *ListIterator) {
-	var argc int = 0
-	listLen := int64(len(([]any)(*list)))
-	if args != nil {
-		argc = len(args)
-	}
-	it = &ListIterator{a: list, count: 0, index: -1, start: 0, stop: listLen - 1, step: 1}
-	if argc >= 1 {
-		if i, err := kern.ToGoInt64(args[0], "start index"); err == nil {
-			if i < 0 {
-				i = listLen + i
-			}
-			it.start = i
-		}
-		if argc >= 2 {
-			if i, err := kern.ToGoInt64(args[1], "stop index"); err == nil {
-				if i < 0 {
-					i = listLen + i
-				}
-				it.stop = i
-			}
-			if argc >= 3 {
-				if i, err := kern.ToGoInt64(args[2], "step"); err == nil {
-					if i < 0 {
-						i = -i
-					}
-					if it.start > it.stop {
-						it.step = -i
-					} else {
-						it.step = i
-					}
-				}
-			}
-		}
-	}
-	it.index = it.start - it.step
-	return
-}
-
-func NewArrayIterator(array []any) (it *ListIterator) {
-	it = &ListIterator{a: (*kern.ListType)(&array), count: 0, index: -1, start: 0, stop: int64(len(array)) - 1, step: 1}
-	return
-}
-
-func (it *ListIterator) String() string {
-	var l = int64(0)
-	if it.a != nil {
-		l = int64(len(*it.a))
-	}
-	return fmt.Sprintf("$([#%d])", l)
-}
-
-func (it *ListIterator) TypeName() string {
-	return "ListIterator"
-}
-
-func (it *ListIterator) HasOperation(name string) bool {
-	//yes := name == expr.NextName || name == expr.ResetName || name == expr.IndexName || name == expr.CountName || name == expr.CurrentName
-	yes := slices.Contains([]string{kern.NextName, kern.ResetName, kern.IndexName, kern.CountName, kern.CurrentName}, name)
-	return yes
-}
-
-func (it *ListIterator) CallOperation(name string, args map[string]any) (v any, err error) {
-	switch name {
-	case kern.NextName:
-		v, err = it.Next()
-	case kern.ResetName:
-		err = it.Reset()
-	case kern.CleanName:
-		err = it.Clean()
-	case kern.IndexName:
-		v = int64(it.Index())
-	case kern.CurrentName:
-		v, err = it.Current()
-	case kern.CountName:
-		v = it.count
-	default:
-		err = kern.ErrNoOperation(name)
-	}
-	return
-}
-
-func (it *ListIterator) Current() (item any, err error) {
-	a := *(it.a)
-	if it.start <= it.stop {
-		if it.stop < int64(len(a)) && it.index >= it.start && it.index <= it.stop {
-			item = a[it.index]
-		} else {
-			err = io.EOF
-		}
-	} else {
-		if it.start < int64(len(a)) && it.index >= it.stop && it.index <= it.start {
-			item = a[it.index]
-		} else {
-			err = io.EOF
-		}
-
-	}
-	return
-}
-
-func (it *ListIterator) Next() (item any, err error) {
-	it.index += it.step
-	if item, err = it.Current(); err != io.EOF {
-		it.count++
-	}
-	return
-}
-
-func (it *ListIterator) Index() int64 {
-	return it.index
-}
-
-func (it *ListIterator) Count() int64 {
-	return it.count
-}
-
-func (it *ListIterator) Reset() error {
-	it.index = it.start - it.step
-	it.count = 0
-	return nil
-}
-
-func (it *ListIterator) Clean() error {
-	return nil
-}

operand-const.go

@@ -0,0 +1,73 @@
+// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
+// All rights reserved.
+
+// operand-const.go
+package expr
+
+// -------- bool const term
+func newBoolTerm(tk *Token) *term {
+	return &term{
+		tk: *tk,
+		// class:    classConst,
+		// kind:     kindBool,
+		parent:   nil,
+		children: nil,
+		position: posLeaf,
+		priority: priValue,
+		evalFunc: evalConst,
+	}
+}
+
+// -------- integer const term
+func newIntegerTerm(tk *Token) *term {
+	return &term{
+		tk:       *tk,
+		parent:   nil,
+		children: nil,
+		position: posLeaf,
+		priority: priValue,
+		evalFunc: evalConst,
+	}
+}
+
+// -------- float const term
+func newFloatTerm(tk *Token) *term {
+	return &term{
+		tk: *tk,
+		// class:    classConst,
+		// kind:     kindFloat,
+		parent:   nil,
+		children: nil,
+		position: posLeaf,
+		priority: priValue,
+		evalFunc: evalConst,
+	}
+}
+
+// -------- string const term
+func newStringTerm(tk *Token) *term {
+	return &term{
+		tk: *tk,
+		// class:    classConst,
+		// kind:     kindString,
+		parent:   nil,
+		children: nil,
+		position: posLeaf,
+		priority: priValue,
+		evalFunc: evalConst,
+	}
+}
+
+// -------- eval func
+func evalConst(ctx ExprContext, self *term) (v any, err error) {
+	v = self.tk.Value
+	return
+}
+
+// init
+func init() {
+	registerTermConstructor(SymString, newStringTerm)
+	registerTermConstructor(SymInteger, newIntegerTerm)
+	registerTermConstructor(SymFloat, newFloatTerm)
+	registerTermConstructor(SymBool, newBoolTerm)
+}

operand-dict.go

@@ -1,38 +0,0 @@
-// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
-// All rights reserved.
-
-// operand-dict.go
-package expr
-
-import (
-	"git.portale-stac.it/go-pkg/expr/kern"
-)
-
-// -------- dict term
-func newDictTerm(args map[any]*term) *term {
-	return &term{
-		tk:       *NewValueToken(0, 0, SymDict, "{}", args),
-		parent:   nil,
-		children: nil,
-		position: posLeaf,
-		priority: priValue,
-		evalFunc: evalDict,
-	}
-}
-
-// -------- dict func
-func evalDict(ctx kern.ExprContext, opTerm *term) (v any, err error) {
-	dict, _ := opTerm.value().(map[any]*term)
-	items := make(kern.DictType, len(dict))
-	for key, tree := range dict {
-		var param any
-		if param, err = tree.Compute(ctx); err != nil {
-			break
-		}
-		items[key] = param
-	}
-	if err == nil {
-		v = &items
-	}
-	return
-}

operand-expr.go

@@ -4,15 +4,10 @@
 // operand-expr.go
 package expr
 
-import (
-	"fmt"
-
-	"git.portale-stac.it/go-pkg/expr/kern"
-)
+import "fmt"
 
 // -------- expr term
-func newExprTerm(root *term) *term {
-	tk := NewValueToken(root.tk.row, root.tk.col, SymExpression, root.Source(), root)
+func newExprTerm(tk *Token) *term {
 	return &term{
 		tk:       *tk,
 		parent:   nil,
@@ -24,11 +19,16 @@ func newExprTerm(root *term) *term {
 }
 
 // -------- eval expr
-func evalExpr(ctx kern.ExprContext, opTerm *term) (v any, err error) {
-	if ast, ok := opTerm.value().(*term); ok {
-		v, err = ast.Compute(ctx)
+func evalExpr(ctx ExprContext, self *term) (v any, err error) {
+	if expr, ok := self.value().(Expr); ok {
+		v, err = expr.eval(ctx, false)
 	} else {
-		err = fmt.Errorf("expression expected, got %T", opTerm.value())
+		err = fmt.Errorf("expression expected, got %T", self.value())
 	}
 	return
 }
+
+// init
+// func init() {
+// 	registerTermConstructor(SymExpression, newExprTerm)
+// }

operand-func.go

@@ -6,56 +6,73 @@ package expr
 
 import (
 	"errors"
-
-	"git.portale-stac.it/go-pkg/expr/kern"
 )
 
 // -------- function call term
 func newFuncCallTerm(tk *Token, args []*term) *term {
-	var pos termPosition = posLeaf
-	if len(args) > 0 {
-		pos = posMultifix
-	}
 	return &term{
 		tk: *tk,
+		// class:    classVar,
+		// kind:     kindUnknown,
 		parent:   nil,
 		children: args,
-		position: pos,
+		position: posLeaf,
 		priority: priValue,
 		evalFunc: evalFuncCall,
 	}
 }
 
 // -------- eval func call
-// func _evalFuncCall(ctx ExprContext, opTerm *term) (v any, err error) {
-// 	name, _ := opTerm.tk.Value.(string)
-// 	params := make([]any, len(opTerm.children), len(opTerm.children)+5)
-// 	for i, tree := range opTerm.children {
-// 		var param any
-// 		if param, err = tree.compute(ctx); err != nil {
-// 			break
-// 		}
-// 		params[i] = param
-// 	}
-
-// 	if err == nil {
-// 		v, err = CallFunction(ctx, name, params)
-// 	}
-// 	return
-// }
-
-func evalFuncCall(ctx kern.ExprContext, opTerm *term) (v any, err error) {
-	name, _ := opTerm.tk.Value.(string)
-	v, err = kern.CallFunctionByTerm(ctx, name, opTerm)
+func evalFuncCall(parentCtx ExprContext, self *term) (v any, err error) {
+	ctx := parentCtx.Clone()
+	name, _ := self.tk.Value.(string)
+	params := make([]any, len(self.children))
+	for i, tree := range self.children {
+		var param any
+		if param, err = tree.compute(ctx); err != nil {
+			break
+		}
+		params[i] = param
+	}
+	if err == nil {
+		if v, err = ctx.Call(name, params); err == nil {
+			exportAll := isEnabled(ctx, control_export_all)
+			// Export variables
+			for _, refName := range ctx.EnumVars(func(name string) bool { return exportAll || name[0] == '@' }) {
+				refValue, _ := ctx.GetVar(refName)
+				exportVar(parentCtx, refName, refValue)
+			}
+			// Export functions
+			for _, refName := range ctx.EnumFuncs(func(name string) bool { return exportAll || name[0] == '@' }) {
+				if info := ctx.GetFuncInfo(refName); info != nil {
+					exportFunc(parentCtx, refName, info)
+				}
+			}
+		}
+	}
 	return
 }
 
+func exportVar(ctx ExprContext, name string, value any) {
+	if name[0] == '@' {
+		name = name[1:]
+	}
+	ctx.setVar(name, value)
+}
+
+func exportFunc(ctx ExprContext, name string, info ExprFunc) {
+	if name[0] == '@' {
+		name = name[1:]
+	}
+	ctx.RegisterFunc(name, info.Functor(), info.MinArgs(), info.MaxArgs())
+}
+
 // -------- function definition term
 func newFuncDefTerm(tk *Token, args []*term) *term {
 	return &term{
-		tk:       *tk, // value is the expression body
+		tk:       *tk,
 		parent:   nil,
-		children: args, // function params
+		children: args, // arg[0]=formal-param-list, arg[1]=*ast
 		position: posLeaf,
 		priority: priValue,
 		evalFunc: evalFuncDef,
@@ -63,23 +80,46 @@ func newFuncDefTerm(tk *Token, args []*term) *term {
 }
 
 // -------- eval func def
-func evalFuncDef(ctx kern.ExprContext, opTerm *term) (v any, err error) {
-	bodySpec := opTerm.value()
-	if ast, ok := bodySpec.(*ast); ok {
-		paramList := make([]kern.ExprFuncParam, 0, len(opTerm.children))
-		for _, param := range opTerm.children {
-			var defValue any
-			flags := paramFlags(0)
-			if len(param.children) > 0 {
-				flags |= PfDefault
-				if defValue, err = param.children[0].Compute(ctx); err != nil {
+// TODO
+type funcDefFunctor struct {
+	params []string
+	expr   Expr
+}
+
+func (functor *funcDefFunctor) Invoke(ctx ExprContext, name string, args []any) (result any, err error) {
+	for i, p := range functor.params {
+		if i < len(args) {
+			arg := args[i]
+			if functor, ok := arg.(Functor); ok {
+				ctx.RegisterFunc(p, functor, 0, -1)
+			} else {
+				ctx.setVar(p, arg)
+			}
+		} else {
+			ctx.setVar(p, nil)
+		}
+	}
+	result, err = functor.expr.eval(ctx, false)
 	return
+}
+
+func evalFuncDef(ctx ExprContext, self *term) (v any, err error) {
+	bodySpec := self.value()
+	if expr, ok := bodySpec.(*ast); ok {
+		paramList := make([]string, 0, len(self.children))
+		for _, param := range self.children {
+			paramList = append(paramList, param.source())
+			// if paramName, ok := param.value().(string); ok {
+			// 	paramList = append(paramList, paramName)
+			// } else {
+			// 	err = fmt.Errorf("invalid function definition: formal param nr %d must be an identifier", i+1)
+			// 	break
+			// }
 		}
+		v = &funcDefFunctor{
+			params: paramList,
+			expr:   expr,
 		}
-			info := NewFuncParamFlagDef(param.Source(), flags, defValue)
-			paramList = append(paramList, info)
-		}
-		v = newExprFunctor(ast, paramList, ctx)
 	} else {
 		err = errors.New("invalid function definition: the body specification must be an expression")
 	}

operand-iterator.go

@@ -1,171 +0,0 @@
-// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
-// All rights reserved.
-
-// operand-iterator.go
-package expr
-
-import (
-	"slices"
-	"strings"
-
-	"git.portale-stac.it/go-pkg/expr/kern"
-)
-
-// -------- iterator term
-
-func newIteratorTerm(tk *Token, args []*term) *term {
-	tk.Sym = SymIterator
-	return &term{
-		tk:       *tk,
-		parent:   nil,
-		children: args,
-		position: posLeaf,
-		priority: priValue,
-		evalFunc: evalIterator,
-	}
-}
-
-// -------- eval iterator
-
-func evalTermArray(ctx kern.ExprContext, terms []*term) (values []any, err error) {
-	values = make([]any, len(terms))
-	for i, t := range terms {
-		var value any
-		if value, err = t.Compute(ctx); err == nil {
-			values[i] = value
-		} else {
-			break
-		}
-	}
-	return
-}
-
-func evalFirstChild(ctx kern.ExprContext, iteratorTerm *term) (value any, err error) {
-	if len(iteratorTerm.children) < 1 || iteratorTerm.children[0] == nil {
-		err = iteratorTerm.Errorf("missing the data-source parameter")
-		return
-	}
-
-	value, err = iteratorTerm.children[0].Compute(ctx)
-	return
-}
-
-func getDataSourceDict(iteratorTerm *term, firstChildValue any) (ds map[string]kern.Functor, err error) {
-	if dictAny, ok := firstChildValue.(*kern.DictType); ok {
-		requiredFields := []string{kern.NextName}
-		fieldsMask := 0b1
-		foundFields := 0
-		ds = make(map[string]kern.Functor)
-		for keyAny, item := range *dictAny {
-			if key, ok := keyAny.(string); ok {
-				if functor, ok := item.(kern.Functor); ok {
-					ds[key] = functor
-					if index := slices.Index(requiredFields, key); index >= 0 {
-						foundFields |= 1 << index
-					}
-				}
-			}
-		}
-		// check required functions
-		if foundFields != fieldsMask {
-			missingFields := make([]string, 0, len(requiredFields))
-			for index, field := range requiredFields {
-				if (foundFields & (1 << index)) == 0 {
-					missingFields = append(missingFields, field)
-				}
-			}
-			err = iteratorTerm.children[0].Errorf("the data-source must provide a non-nil %q operator(s)", strings.Join(missingFields, ", "))
-		}
-	}
-	return
-}
-
-func evalIterator(ctx kern.ExprContext, opTerm *term) (v any, err error) {
-	var firstChildValue any
-	var ds map[string]kern.Functor
-
-	if firstChildValue, err = evalFirstChild(ctx, opTerm); err != nil {
-		return
-	}
-
-	if ds, err = getDataSourceDict(opTerm, firstChildValue); err != nil && ds == nil {
-		return
-	}
-	err = nil
-
-	if ds != nil {
-		if len(ds) > 0 {
-			var dc *dataCursor
-			dcCtx := ctx.Clone()
-			if initFunc, exists := ds[kern.InitName]; exists && initFunc != nil {
-				var args []any
-				var resource any
-				if len(opTerm.children) > 1 {
-					if args, err = evalTermArray(ctx, opTerm.children[1:]); err != nil {
-						return
-					}
-				} else {
-					args = []any{}
-				}
-
-				actualParams := kern.BindActualParams(initFunc, args)
-
-				initCtx := ctx.Clone()
-				if resource, err = initFunc.InvokeNamed(initCtx, kern.InitName, actualParams); err != nil {
-					return
-				}
-				kern.ExportObjects(dcCtx, initCtx)
-				dc = NewDataCursor(dcCtx, ds, resource)
-			} else {
-				dc = NewDataCursor(dcCtx, ds, nil)
-			}
-
-			v = dc
-		} else {
-			if dictIt, ok := firstChildValue.(*kern.DictType); ok {
-				var args []any
-				if args, err = evalSibling(ctx, opTerm.children, nil); err == nil {
-					v, err = NewDictIterator(dictIt, args)
-				}
-			} else {
-				err = opTerm.children[0].Errorf("the data-source must be a dictionary")
-			}
-		}
-	} else if list, ok := firstChildValue.(*kern.ListType); ok {
-		var args []any
-		if args, err = evalSibling(ctx, opTerm.children, nil); err == nil {
-			v = NewListIterator(list, args)
-		}
-	} else if intVal, ok := firstChildValue.(int64); ok {
-		var args []any
-		if args, err = evalSibling(ctx, opTerm.children, intVal); err == nil {
-			v, err = NewIntIterator(args)
-		}
-	} else {
-		var list []any
-		if list, err = evalSibling(ctx, opTerm.children, firstChildValue); err == nil {
-			v = NewArrayIterator(list)
-		}
-	}
-	return
-}
-
-func evalSibling(ctx kern.ExprContext, terms []*term, firstChildValue any) (list []any, err error) {
-	items := make([]any, 0, len(terms))
-	for i, tree := range terms {
-		var param any
-		if i == 0 {
-			if firstChildValue == nil {
-				continue
-			}
-			param = firstChildValue
-		} else if param, err = tree.Compute(ctx); err != nil {
-			break
-		}
-		items = append(items, param)
-	}
-	if err == nil {
-		list = items
-	}
-	return
-}

operand-list.go

@@ -4,18 +4,14 @@
 // operand-list.go
 package expr
 
-import (
-	"git.portale-stac.it/go-pkg/expr/kern"
-)
-
 // -------- list term
 func newListTermA(args ...*term) *term {
-	return newListTerm(0, 0, args)
+	return newListTerm(args)
 }
 
-func newListTerm(row, col int, args []*term) *term {
+func newListTerm(args []*term) *term {
 	return &term{
-		tk:       *NewValueToken(row, col, SymList, "[]", args),
+		tk:       *NewValueToken(0, 0, SymList, "[]", args),
 		parent:   nil,
 		children: nil,
 		position: posLeaf,
@@ -25,18 +21,46 @@ func newListTerm(row, col int, args []*term) *term {
 }
 
 // -------- list func
-func evalList(ctx kern.ExprContext, opTerm *term) (v any, err error) {
-	list, _ := opTerm.value().([]*term)
-	items := make(kern.ListType, len(list))
+func evalList(ctx ExprContext, self *term) (v any, err error) {
+	list, _ := self.value().([]*term)
+	items := make([]any, len(list))
 	for i, tree := range list {
 		var param any
-		if param, err = tree.Compute(ctx); err != nil {
+		if param, err = tree.compute(ctx); err != nil {
 			break
 		}
 		items[i] = param
 	}
 	if err == nil {
-		v = &items
+		v = items
 	}
 	return
 }
+
+// // -------- list term
+// func newListTerm(args []*term) *term {
+// 	return &term{
+// 		tk:       *NewToken(0, 0, SymList, "[]"),
+// 		parent:   nil,
+// 		children: args,
+// 		position: posLeaf,
+// 		priority: priValue,
+// 		evalFunc: evalList,
+// 	}
+// }
+
+// // -------- list func
+// func evalList(ctx ExprContext, self *term) (v any, err error) {
+// 	items := make([]any, len(self.children))
+// 	for i, tree := range self.children {
+// 		var param any
+// 		if param, err = tree.compute(ctx); err != nil {
+// 			break
+// 		}
+// 		items[i] = param
+// 	}
+// 	if err == nil {
+// 		v = items
+// 	}
+// 	return
+// }

operand-literal.go

@@ -1,37 +0,0 @@
-// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
-// All rights reserved.
-
-// operand-literal.go
-package expr
-
-import (
-	"git.portale-stac.it/go-pkg/expr/kern"
-)
-
-// -------- literal term
-func newLiteralTerm(tk *Token) *term {
-	return &term{
-		tk:       *tk,
-		parent:   nil,
-		children: nil,
-		position: posLeaf,
-		priority: priValue,
-		evalFunc: evalLiteral,
-	}
-}
-
-// -------- eval func
-func evalLiteral(ctx kern.ExprContext, opTerm *term) (v any, err error) {
-	v = opTerm.tk.Value
-	return
-}
-
-// init
-func init() {
-	registerTermConstructor(SymString, newLiteralTerm)
-	registerTermConstructor(SymInteger, newLiteralTerm)
-	registerTermConstructor(SymFloat, newLiteralTerm)
-	registerTermConstructor(SymFraction, newLiteralTerm)
-	registerTermConstructor(SymBool, newLiteralTerm)
-	registerTermConstructor(SymKwNil, newLiteralTerm)
-}

operand-selector-case.go

@@ -7,8 +7,6 @@ package expr
 import (
 	"fmt"
 	"strings"
-
-	"git.portale-stac.it/go-pkg/expr/kern"
 )
 
 // -------- selector case term
@@ -43,10 +41,10 @@ func newSelectorCaseTerm(row, col int, filterList *term, caseExpr Expr) *term {
 }
 
 // -------- eval selector case
-func evalSelectorCase(ctx kern.ExprContext, opTerm *term) (v any, err error) {
+func evalSelectorCase(ctx ExprContext, self *term) (v any, err error) {
 	var ok bool
-	if v, ok = opTerm.value().(*selectorCase); !ok {
-		err = fmt.Errorf("selector-case expected, got %T", opTerm.value())
+	if v, ok = self.value().(*selectorCase); !ok {
+		err = fmt.Errorf("selector-case expected, got %T", self.value())
 	}
 	return
 }

operand-var.go

@@ -4,36 +4,27 @@
 // operand-var.go
 package expr
 
-import (
-	"fmt"
-
-	"git.portale-stac.it/go-pkg/expr/kern"
-)
+import "fmt"
 
 // -------- variable term
 func newVarTerm(tk *Token) *term {
-	t := &term{
+	return &term{
 		tk: *tk,
+		// class:    classVar,
+		// kind:     kindUnknown,
 		parent:   nil,
 		children: nil,
 		position: posLeaf,
 		priority: priValue,
 		evalFunc: evalVar,
 	}
-	t.tk.Sym = SymVariable
-	return t
 }
 
 // -------- eval func
-func evalVar(ctx kern.ExprContext, opTerm *term) (v any, err error) {
+func evalVar(ctx ExprContext, self *term) (v any, err error) {
 	var exists bool
-	name := opTerm.Source()
-	if v, exists = ctx.GetVar(name); !exists {
-		if info, exists := ctx.GetFuncInfo(name); exists {
-			v = info.Functor()
-		} else {
-			err = fmt.Errorf("undefined variable or function %q", name)
-		}
+	if v, exists = ctx.GetVar(self.tk.source); !exists {
+		err = fmt.Errorf("undefined variable %q", self.tk.source)
 	}
 	return
 }

operator-assign.go

@@ -1,14 +1,9 @@
 // Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
-// All rights reserightChilded.
+// All rights reserved.
 
 // operator-assign.go
 package expr
 
-import (
-	"git.portale-stac.it/go-pkg/expr/kern"
-	"git.portale-stac.it/go-pkg/expr/util"
-)
-
 //-------- assign term
 
 func newAssignTerm(tk *Token) (inst *term) {
@@ -21,189 +16,22 @@ func newAssignTerm(tk *Token) (inst *term) {
 	}
 }
 
-func assignCollectionItem(ctx kern.ExprContext, collectionTerm, keyListTerm *term, value any) (err error) {
-	var collectionValue, keyListValue, keyValue any
-	var keyList *kern.ListType
-	var ok bool
-
-	if collectionValue, err = collectionTerm.Compute(ctx); err != nil {
+func evalAssign(ctx ExprContext, self *term) (v any, err error) {
+	if err = self.checkOperands(); err != nil {
 		return
 	}
 
-	if keyListValue, err = keyListTerm.Compute(ctx); err != nil {
-		return
-	} else if keyList, ok = keyListValue.(*kern.ListType); !ok || len(*keyList) != 1 {
-		err = keyListTerm.Errorf("index/key specification expected, got %v [%s]", keyListValue, kern.TypeName(keyListValue))
-		return
-	}
-	if keyValue = (*keyList)[0]; keyValue == nil {
-		err = keyListTerm.Errorf("index/key is nil")
+	leftTerm := self.children[0]
+	if leftTerm.tk.Sym != SymIdentifier {
+		err = leftTerm.tk.Errorf("left operand of %q must be a variable", self.tk.source)
 		return
 	}
 
-	switch collection := collectionValue.(type) {
-	case *kern.ListType:
-		if index, ok := keyValue.(int64); ok {
-			err = collection.SetItem(index, value)
+	if v, err = self.children[1].compute(ctx); err == nil {
+		if functor, ok := v.(Functor); ok {
+			ctx.RegisterFunc(leftTerm.source(), functor, 0, -1)
 		} else {
-			err = keyListTerm.Errorf("integer expected, got %v [%s]", keyValue, kern.TypeName(keyValue))
-		}
-	case *kern.DictType:
-		collection.SetItem(keyValue, value)
-	default:
-		err = collectionTerm.Errorf("collection expected")
-	}
-	return
-}
-
-func assignValue(ctx kern.ExprContext, leftTerm *term, v any) (err error) {
-	if leftTerm.symbol() == SymIndex {
-		err = assignCollectionItem(ctx, leftTerm.children[0], leftTerm.children[1], v)
-	} else {
-		ctx.UnsafeSetVar(leftTerm.Source(), v)
-	}
-	return
-}
-
-func evalAssign(ctx kern.ExprContext, opTerm *term) (v any, err error) {
-	if err = opTerm.checkOperands(); err != nil {
-		return
-	}
-
-	leftTerm := opTerm.children[0]
-	leftSym := leftTerm.symbol()
-	if leftSym != SymVariable && leftSym != SymIndex {
-		err = leftTerm.tk.Errorf("left operand of %q must be a variable or a collection's item", opTerm.tk.source)
-		return
-	}
-
-	rightChild := opTerm.children[1]
-
-	if v, err = rightChild.Compute(ctx); err == nil {
-		if functor, ok := v.(kern.Functor); ok {
-			if leftSym == SymVariable {
-				if info := functor.GetFunc(); info != nil {
-					ctx.RegisterFunc(leftTerm.Source(), info.Functor(), info.ReturnType(), info.Params())
-				} else if funcDef, ok := functor.(*exprFunctor); ok {
-					paramSpecs := util.ForAll(funcDef.params, func(p kern.ExprFuncParam) kern.ExprFuncParam { return p })
-
-					ctx.RegisterFunc(leftTerm.Source(), functor, kern.TypeAny, paramSpecs)
-				} else {
-					err = opTerm.Errorf("unknown function %s()", rightChild.Source())
-				}
-			} else {
-				err = assignValue(ctx, leftTerm, v)
-			}
-		} else {
-			err = assignValue(ctx, leftTerm, v)
-		}
-	}
-	if err != nil {
-		v = nil
-	}
-	return
-}
-
-//-------- assign term
-
-func newOpAssignTerm(tk *Token) (inst *term) {
-	return &term{
-		tk:       *tk,
-		children: make([]*term, 0, 2),
-		position: posInfix,
-		priority: priAssign,
-		evalFunc: evalOpAssign,
-	}
-}
-
-func getCollectionItemValue(ctx kern.ExprContext, collectionTerm, keyListTerm *term) (value any, err error) {
-	var collectionValue, keyListValue, keyValue any
-	var keyList *kern.ListType
-	var ok bool
-
-	if collectionValue, err = collectionTerm.Compute(ctx); err != nil {
-		return
-	}
-
-	if keyListValue, err = keyListTerm.Compute(ctx); err != nil {
-		return
-	} else if keyList, ok = keyListValue.(*kern.ListType); !ok || len(*keyList) != 1 {
-		err = keyListTerm.Errorf("index/key specification expected, got %v [%s]", keyListValue, kern.TypeName(keyListValue))
-		return
-	}
-	if keyValue = (*keyList)[0]; keyValue == nil {
-		err = keyListTerm.Errorf("index/key is nil")
-		return
-	}
-
-	switch collection := collectionValue.(type) {
-	case *kern.ListType:
-		if index, ok := keyValue.(int64); ok {
-			value = (*collection)[index]
-		} else {
-			err = keyListTerm.Errorf("integer expected, got %v [%s]", keyValue, kern.TypeName(keyValue))
-		}
-	case *kern.DictType:
-		value = (*collection)[keyValue]
-	default:
-		err = collectionTerm.Errorf("collection expected")
-	}
-	return
-}
-
-func getAssignValue(ctx kern.ExprContext, leftTerm *term) (value any, err error) {
-	if leftTerm.symbol() == SymIndex {
-		value, err = getCollectionItemValue(ctx, leftTerm.children[0], leftTerm.children[1])
-	} else {
-		value, _ = ctx.GetVar(leftTerm.Source())
-	}
-	return
-}
-
-func evalOpAssign(ctx kern.ExprContext, opTerm *term) (v any, err error) {
-	var rightValue, leftValue any
-	if err = opTerm.checkOperands(); err != nil {
-		return
-	}
-
-	leftTerm := opTerm.children[0]
-	leftSym := leftTerm.symbol()
-	if leftSym != SymVariable && leftSym != SymIndex {
-		err = leftTerm.tk.Errorf("left operand of %q must be a variable or a collection's item", opTerm.tk.source)
-		return
-	}
-
-	rightChild := opTerm.children[1]
-
-	if rightValue, err = rightChild.Compute(ctx); err == nil {
-		if leftValue, err = getAssignValue(ctx, leftTerm); err == nil {
-			switch opTerm.symbol() {
-			case SymPlusEqual:
-				v, err = sumValues(opTerm, leftValue, rightValue)
-			case SymMinusEqual:
-				v, err = diffValues(opTerm, leftValue, rightValue)
-			case SymStarEqual:
-				v, err = mulValues(opTerm, leftValue, rightValue)
-			case SymSlashEqual:
-				v, err = divValues(opTerm, leftValue, rightValue)
-			case SymPercEqual:
-				v, err = remainderValues(opTerm, leftValue, rightValue)
-			case SymAmpersandEqual:
-				v, err = bitwiseAnd(opTerm, leftValue, rightValue)
-			case SymVertBarEqual:
-				v, err = bitwiseOr(opTerm, leftValue, rightValue)
-			case SymCaretEqual:
-				v, err = bitwiseXor(opTerm, leftValue, rightValue)
-			case SymDoubleLessEqual:
-				v, err = bitLeftShift(opTerm, leftValue, rightValue)
-			case SymDoubleGreaterEqual:
-				v, err = bitRightShift(opTerm, leftValue, rightValue)
-			default:
-				err = opTerm.Errorf("unsupported assign operator %q", opTerm.Source())
-			}
-			if err == nil {
-				err = assignValue(ctx, leftTerm, v)
-			}
+			ctx.setVar(leftTerm.tk.source, v)
 		}
 	}
 	return
@@ -212,14 +40,4 @@ func evalOpAssign(ctx kern.ExprContext, opTerm *term) (v any, err error) {
 // init
 func init() {
 	registerTermConstructor(SymEqual, newAssignTerm)
-	registerTermConstructor(SymPlusEqual, newOpAssignTerm)
-	registerTermConstructor(SymMinusEqual, newOpAssignTerm)
-	registerTermConstructor(SymStarEqual, newOpAssignTerm)
-	registerTermConstructor(SymSlashEqual, newOpAssignTerm)
-	registerTermConstructor(SymPercEqual, newOpAssignTerm)
-	registerTermConstructor(SymDoubleLessEqual, newOpAssignTerm)
-	registerTermConstructor(SymDoubleGreaterEqual, newOpAssignTerm)
-	registerTermConstructor(SymAmpersandEqual, newOpAssignTerm)
-	registerTermConstructor(SymVertBarEqual, newOpAssignTerm)
-	registerTermConstructor(SymCaretEqual, newOpAssignTerm)
 }

operator-bitwise.go

@@ -1,158 +0,0 @@
-// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
-// All rights reserved.
-
-// operator-bitwise.go
-package expr
-
-import (
-	"git.portale-stac.it/go-pkg/expr/kern"
-)
-
-//-------- Bitwise NOT term
-
-func newBitwiseNotTerm(tk *Token) (inst *term) {
-	return &term{
-		tk:       *tk,
-		children: make([]*term, 0, 1),
-		position: posPrefix,
-		priority: priBitwiseNot,
-		evalFunc: evalBitwiseNot,
-	}
-}
-
-func evalBitwiseNot(ctx kern.ExprContext, opTerm *term) (v any, err error) {
-	var value any
-
-	if value, err = opTerm.evalPrefix(ctx); err != nil {
-		return
-	}
-
-	if kern.IsInteger(value) {
-		i, _ := value.(int64)
-		v = ^i
-	} else {
-		err = opTerm.errIncompatiblePrefixPostfixType(value)
-	}
-	return
-}
-
-//-------- Bitwise AND term
-
-func newBitwiseAndTerm(tk *Token) (inst *term) {
-	return &term{
-		tk:       *tk,
-		children: make([]*term, 0, 2),
-		position: posInfix,
-		priority: priBitwiseAnd,
-		evalFunc: evalBitwiseAnd,
-	}
-}
-
-func bitwiseAnd(opTerm *term, leftValue, rightValue any) (v any, err error) {
-	var leftInt, rightInt int64
-	var lok, rok bool
-
-	leftInt, lok = leftValue.(int64)
-	rightInt, rok = rightValue.(int64)
-
-	if lok && rok {
-		v = leftInt & rightInt
-	} else {
-		err = opTerm.errIncompatibleTypes(leftValue, rightValue)
-	}
-	return
-}
-
-func evalBitwiseAnd(ctx kern.ExprContext, opTerm *term) (v any, err error) {
-	var leftValue, rightValue any
-
-	if leftValue, rightValue, err = opTerm.evalInfix(ctx); err != nil {
-		return
-	}
-	v, err = bitwiseAnd(opTerm, leftValue, rightValue)
-	return
-}
-
-//-------- Bitwise OR term
-
-func newBitwiseOrTerm(tk *Token) (inst *term) {
-	return &term{
-		tk:       *tk,
-		children: make([]*term, 0, 2),
-		position: posInfix,
-		priority: priBitwiseOr,
-		evalFunc: evalBitwiseOr,
-	}
-}
-
-func bitwiseOr(opTerm *term, leftValue, rightValue any) (v any, err error) {
-	var leftInt, rightInt int64
-	var lok, rok bool
-
-	leftInt, lok = leftValue.(int64)
-	rightInt, rok = rightValue.(int64)
-
-	if lok && rok {
-		v = leftInt | rightInt
-	} else {
-		err = opTerm.errIncompatibleTypes(leftValue, rightValue)
-	}
-	return
-}
-
-func evalBitwiseOr(ctx kern.ExprContext, opTerm *term) (v any, err error) {
-	var leftValue, rightValue any
-
-	if leftValue, rightValue, err = opTerm.evalInfix(ctx); err != nil {
-		return
-	}
-
-	v, err = bitwiseOr(opTerm, leftValue, rightValue)
-	return
-}
-
-//-------- Bitwise XOR term
-
-func newBitwiseXorTerm(tk *Token) (inst *term) {
-	return &term{
-		tk:       *tk,
-		children: make([]*term, 0, 2),
-		position: posInfix,
-		priority: priBitwiseOr,
-		evalFunc: evalBitwiseXor,
-	}
-}
-
-func bitwiseXor(opTerm *term, leftValue, rightValue any) (v any, err error) {
-	var leftInt, rightInt int64
-	var lok, rok bool
-
-	leftInt, lok = leftValue.(int64)
-	rightInt, rok = rightValue.(int64)
-
-	if lok && rok {
-		v = leftInt ^ rightInt
-	} else {
-		err = opTerm.errIncompatibleTypes(leftValue, rightValue)
-	}
-	return
-}
-
-func evalBitwiseXor(ctx kern.ExprContext, opTerm *term) (v any, err error) {
-	var leftValue, rightValue any
-
-	if leftValue, rightValue, err = opTerm.evalInfix(ctx); err != nil {
-		return
-	}
-
-	v, err = bitwiseXor(opTerm, leftValue, rightValue)
-	return
-}
-
-// init
-func init() {
-	registerTermConstructor(SymTilde, newBitwiseNotTerm)
-	registerTermConstructor(SymAmpersand, newBitwiseAndTerm)
-	registerTermConstructor(SymVertBar, newBitwiseOrTerm)
-	registerTermConstructor(SymCaret, newBitwiseXorTerm)
-}

operator-bool.go

@@ -4,11 +4,7 @@
 // operator-bool.go
 package expr
 
-import (
-	"fmt"
-
-	"git.portale-stac.it/go-pkg/expr/kern"
-)
+import "fmt"
 
 //-------- NOT term
 
@@ -22,17 +18,17 @@ func newNotTerm(tk *Token) (inst *term) {
 	}
 }
 
-func evalNot(ctx kern.ExprContext, opTerm *term) (v any, err error) {
+func evalNot(ctx ExprContext, self *term) (v any, err error) {
 	var rightValue any
 
-	if rightValue, err = opTerm.evalPrefix(ctx); err != nil {
+	if rightValue, err = self.evalPrefix(ctx); err != nil {
 		return
 	}
 
-	if b, ok := kern.ToBool(rightValue); ok {
+	if b, ok := toBool(rightValue); ok {
 		v = !b
 	} else {
-		err = opTerm.errIncompatiblePrefixPostfixType(rightValue)
+		err = self.errIncompatibleType(rightValue)
 	}
 	return
 }
@@ -42,6 +38,8 @@ func evalNot(ctx kern.ExprContext, opTerm *term) (v any, err error) {
 func newAndTerm(tk *Token) (inst *term) {
 	return &term{
 		tk: *tk,
+		// class:    classOperator,
+		// kind:     kindBool,
 		children: make([]*term, 0, 2),
 		position: posInfix,
 		priority: priAnd,
@@ -49,8 +47,8 @@ func newAndTerm(tk *Token) (inst *term) {
 	}
 }
 
-func evalAnd(ctx kern.ExprContext, self *term) (v any, err error) {
-	if kern.CtrlIsEnabled(ctx, kern.ControlBoolShortcut) {
+func evalAnd(ctx ExprContext, self *term) (v any, err error) {
+	if isEnabled(ctx, ControlBoolShortcut) {
 		v, err = evalAndWithShortcut(ctx, self)
 	} else {
 		v, err = evalAndWithoutShortcut(ctx, self)
@@ -58,7 +56,7 @@ func evalAnd(ctx kern.ExprContext, self *term) (v any, err error) {
 	return
 }
 
-func evalAndWithoutShortcut(ctx kern.ExprContext, self *term) (v any, err error) {
+func evalAndWithoutShortcut(ctx ExprContext, self *term) (v any, err error) {
 	var leftValue, rightValue any
 	var leftBool, rightBool bool
 	var lok, rok bool
@@ -67,8 +65,8 @@ func evalAndWithoutShortcut(ctx kern.ExprContext, self *term) (v any, err error)
 		return
 	}
 
-	leftBool, lok = kern.ToBool(leftValue)
-	rightBool, rok = kern.ToBool(rightValue)
+	leftBool, lok = toBool(leftValue)
+	rightBool, rok = toBool(rightValue)
 
 	if lok && rok {
 		v = leftBool && rightBool
@@ -78,25 +76,24 @@ func evalAndWithoutShortcut(ctx kern.ExprContext, self *term) (v any, err error)
 	return
 }
 
-func evalAndWithShortcut(ctx kern.ExprContext, self *term) (v any, err error) {
+func evalAndWithShortcut(ctx ExprContext, self *term) (v any, err error) {
 	var leftValue, rightValue any
 
 	if err = self.checkOperands(); err != nil {
 		return
 	}
 
-	if leftValue, err = self.children[0].Compute(ctx); err != nil {
+	if leftValue, err = self.children[0].compute(ctx); err != nil {
 		return
 	}
 
-	if leftBool, lok := kern.ToBool(leftValue); !lok {
-		// err = fmt.Errorf("got %s as left operand type of 'AND' operator, it must be bool", expr.TypeName(leftValue))
-		// return
-		err = self.errIncompatibleType(leftValue, "left")
+	if leftBool, lok := toBool(leftValue); !lok {
+		err = fmt.Errorf("got %T as left operand type of 'and' operator, it must be bool", leftBool)
+		return
 	} else if !leftBool {
 		v = false
-	} else if rightValue, err = self.children[1].Compute(ctx); err == nil {
-		if rightBool, rok := kern.ToBool(rightValue); rok {
+	} else if rightValue, err = self.children[1].compute(ctx); err == nil {
+		if rightBool, rok := toBool(rightValue); rok {
 			v = rightBool
 		} else {
 			err = self.errIncompatibleTypes(leftValue, rightValue)
@@ -110,6 +107,8 @@ func evalAndWithShortcut(ctx kern.ExprContext, self *term) (v any, err error) {
 func newOrTerm(tk *Token) (inst *term) {
 	return &term{
 		tk: *tk,
+		// class:    classOperator,
+		// kind:     kindBool,
 		children: make([]*term, 0, 2),
 		position: posInfix,
 		priority: priOr,
@@ -117,8 +116,8 @@ func newOrTerm(tk *Token) (inst *term) {
 	}
 }
 
-func evalOr(ctx kern.ExprContext, self *term) (v any, err error) {
-	if kern.CtrlIsEnabled(ctx, kern.ControlBoolShortcut) {
+func evalOr(ctx ExprContext, self *term) (v any, err error) {
+	if isEnabled(ctx, ControlBoolShortcut) {
 		v, err = evalOrWithShortcut(ctx, self)
 	} else {
 		v, err = evalOrWithoutShortcut(ctx, self)
@@ -126,7 +125,7 @@ func evalOr(ctx kern.ExprContext, self *term) (v any, err error) {
 	return
 }
 
-func evalOrWithoutShortcut(ctx kern.ExprContext, self *term) (v any, err error) {
+func evalOrWithoutShortcut(ctx ExprContext, self *term) (v any, err error) {
 	var leftValue, rightValue any
 	var leftBool, rightBool bool
 	var lok, rok bool
@@ -135,8 +134,8 @@ func evalOrWithoutShortcut(ctx kern.ExprContext, self *term) (v any, err error)
 		return
 	}
 
-	leftBool, lok = kern.ToBool(leftValue)
-	rightBool, rok = kern.ToBool(rightValue)
+	leftBool, lok = toBool(leftValue)
+	rightBool, rok = toBool(rightValue)
 
 	if lok && rok {
 		v = leftBool || rightBool
@@ -146,24 +145,24 @@ func evalOrWithoutShortcut(ctx kern.ExprContext, self *term) (v any, err error)
 	return
 }
 
-func evalOrWithShortcut(ctx kern.ExprContext, self *term) (v any, err error) {
+func evalOrWithShortcut(ctx ExprContext, self *term) (v any, err error) {
 	var leftValue, rightValue any
 
 	if err = self.checkOperands(); err != nil {
 		return
 	}
 
-	if leftValue, err = self.children[0].Compute(ctx); err != nil {
+	if leftValue, err = self.children[0].compute(ctx); err != nil {
 		return
 	}
 
-	if leftBool, lok := kern.ToBool(leftValue); !lok {
-		err = fmt.Errorf("got %s as left operand type of 'OR' operator, it must be bool", kern.TypeName(leftValue))
+	if leftBool, lok := toBool(leftValue); !lok {
+		err = fmt.Errorf("got %T as left operand type of 'or' operator, it must be bool", leftBool)
 		return
 	} else if leftBool {
 		v = true
-	} else if rightValue, err = self.children[1].Compute(ctx); err == nil {
-		if rightBool, rok := kern.ToBool(rightValue); rok {
+	} else if rightValue, err = self.children[1].compute(ctx); err == nil {
+		if rightBool, rok := toBool(rightValue); rok {
 			v = rightBool
 		} else {
 			err = self.errIncompatibleTypes(leftValue, rightValue)

operator-builtin.go

@@ -1,15 +1,9 @@
 // Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
 // All rights reserved.
 
-// operator-builtin.go
+// operator-length.go
 package expr
 
-import (
-	"io"
-
-	"git.portale-stac.it/go-pkg/expr/kern"
-)
-
 //-------- builtin term
 
 func newBuiltinTerm(tk *Token) (inst *term) {
@@ -22,42 +16,37 @@ func newBuiltinTerm(tk *Token) (inst *term) {
 	}
 }
 
-func evalBuiltin(ctx kern.ExprContext, opTerm *term) (v any, err error) {
-	var childValue any
+func evalBuiltin(ctx ExprContext, self *term) (v any, err error) {
+	var rightValue any
 
-	if childValue, err = opTerm.evalPrefix(ctx); err != nil {
+	if rightValue, err = self.evalPrefix(ctx); err != nil {
 		return
 	}
 
 	count := 0
-	if kern.IsString(childValue) {
-		module, _ := childValue.(string)
-		count, err = ImportInContextByGlobPattern(ctx, module)
-	} else {
-		var moduleSpec any
-		var it kern.Iterator
-		if it, err = NewIterator(childValue); err != nil {
-			return
-		}
-		for moduleSpec, err = it.Next(); err == nil; moduleSpec, err = it.Next() {
+	if isList(rightValue) {
+		list, _ := rightValue.([]any)
+		for i, moduleSpec := range list {
 			if module, ok := moduleSpec.(string); ok {
 				if ImportInContext(ctx, module) {
 					count++
 				} else {
-					err = opTerm.Errorf("unknown builtin module %q", module)
+					err = self.Errorf("unknown module %q", module)
 					break
 				}
 			} else {
-				err = opTerm.Errorf("expected string at item nr %d, got %s", it.Index()+1, kern.TypeName(moduleSpec))
+				err = self.Errorf("expected string at item nr %d, got %T", i+1, moduleSpec)
 				break
 			}
 		}
-		if err == io.EOF {
-			err = nil
-		}
+	} else if isString(rightValue) {
+		module, _ := rightValue.(string)
+		count, err = ImportInContextByGlobPattern(ctx, module)
+	} else {
+		err = self.errIncompatibleType(rightValue)
 	}
 	if err == nil {
-		v = int64(count)
+		v = count
 	}
 	return
 }

operator-but.go

@@ -4,10 +4,6 @@
 // operator-but.go
 package expr
 
-import (
-	"git.portale-stac.it/go-pkg/expr/kern"
-)
-
 //-------- but term
 
 func newButTerm(tk *Token) (inst *term) {
@@ -20,8 +16,8 @@ func newButTerm(tk *Token) (inst *term) {
 	}
 }
 
-func evalBut(ctx kern.ExprContext, opTerm *term) (v any, err error) {
-	_, v, err = opTerm.evalInfix(ctx)
+func evalBut(ctx ExprContext, self *term) (v any, err error) {
+	_, v, err = self.evalInfix(ctx)
 	return
 }
 

operator-coalesce.go

@@ -0,0 +1,93 @@
+// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
+// All rights reserved.
+
+// operator-coalesce.go
+package expr
+
+//-------- null coalesce term
+
+func newNullCoalesceTerm(tk *Token) (inst *term) {
+	return &term{
+		tk: *tk,
+		// class:    classOperator,
+		// kind:     kindUnknown,
+		children: make([]*term, 0, 2),
+		position: posInfix,
+		priority: priCoalesce,
+		evalFunc: evalNullCoalesce,
+	}
+}
+
+func evalNullCoalesce(ctx ExprContext, self *term) (v any, err error) {
+	var rightValue any
+
+	if err = self.checkOperands(); err != nil {
+		return
+	}
+
+	leftTerm := self.children[0]
+	if leftTerm.tk.Sym != SymIdentifier {
+		err = leftTerm.Errorf("left operand of %q must be a variable", self.tk.source)
+		return
+	}
+
+	if leftValue, exists := ctx.GetVar(leftTerm.source()); exists {
+		v = leftValue
+	} else if rightValue, err = self.children[1].compute(ctx); err == nil {
+		if _, ok := rightValue.(Functor); ok {
+			err = errCoalesceNoFunc(self.children[1])
+		} else {
+			v = rightValue
+		}
+	}
+	return
+}
+
+//-------- coalesce assign term
+
+func newCoalesceAssignTerm(tk *Token) (inst *term) {
+	return &term{
+		tk:       *tk,
+		children: make([]*term, 0, 2),
+		position: posInfix,
+		priority: priCoalesce,
+		evalFunc: evalAssignCoalesce,
+	}
+}
+
+func evalAssignCoalesce(ctx ExprContext, self *term) (v any, err error) {
+	var rightValue any
+
+	if err = self.checkOperands(); err != nil {
+		return
+	}
+
+	leftTerm := self.children[0]
+	if leftTerm.tk.Sym != SymIdentifier {
+		err = leftTerm.Errorf("left operand of %q must be a variable", self.tk.source)
+		return
+	}
+
+	if leftValue, exists := ctx.GetVar(leftTerm.source()); exists {
+		v = leftValue
+	} else if rightValue, err = self.children[1].compute(ctx); err == nil {
+		if _, ok := rightValue.(Functor); ok {
+			err = errCoalesceNoFunc(self.children[1])
+		} else {
+			v = rightValue
+			ctx.setVar(leftTerm.source(), rightValue)
+		}
+	}
+	return
+}
+
+// utils
+func errCoalesceNoFunc(t *term) error {
+	return t.Errorf("the right operand of a coalescing operation cannot be a function definition")
+}
+
+// init
+func init() {
+	registerTermConstructor(SymDoubleQuestion, newNullCoalesceTerm)
+	registerTermConstructor(SymQuestionEqual, newCoalesceAssignTerm)
+}

operator-context.go

@@ -1,64 +0,0 @@
-// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
-// All rights reserved.
-
-// operator-context-value.go
-package expr
-
-import (
-	"git.portale-stac.it/go-pkg/expr/kern"
-)
-
-//-------- context term
-
-func newContextTerm(tk *Token) (inst *term) {
-	return &term{
-		tk:       *tk,
-		children: make([]*term, 0, 1),
-		position: posPrefix,
-		priority: priIncDec,
-		evalFunc: evalContextValue,
-	}
-}
-
-func evalContextValue(ctx kern.ExprContext, opTerm *term) (v any, err error) {
-	var childValue any
-
-	var sourceCtx kern.ExprContext
-	if len(opTerm.children) == 0 {
-		sourceCtx = ctx
-	} else if opTerm.children[0].symbol() == SymVariable && opTerm.children[0].Source() == "global" {
-		sourceCtx = ctx.GetGlobal()
-	} else if childValue, err = opTerm.evalPrefix(ctx); err == nil {
-		if dc, ok := childValue.(*dataCursor); ok {
-			sourceCtx = dc.ctx
-		}
-	}
-
-	if sourceCtx != nil {
-		if formatter, ok := sourceCtx.(kern.DictFormat); ok {
-			v = formatter.ToDict()
-		} else if formatter, ok := sourceCtx.(kern.Formatter); ok {
-			v = formatter.ToString(0)
-		} else {
-			// keys := sourceCtx.EnumVars(func(name string) bool { return name[0] != '_' })
-			keys := sourceCtx.EnumVars(nil)
-			d := make(map[string]any)
-			for _, key := range keys {
-				d[key], _ = sourceCtx.GetVar(key)
-			}
-			keys = sourceCtx.EnumFuncs(func(name string) bool { return true })
-			for _, key := range keys {
-				d[key], _ = sourceCtx.GetFuncInfo(key)
-			}
-			v = d
-		}
-	} else {
-		err = opTerm.errIncompatiblePrefixPostfixType(childValue)
-	}
-	return
-}
-
-// init
-func init() {
-	registerTermConstructor(SymDoubleDollar, newContextTerm)
-}

operator-ctrl.go

@@ -4,10 +4,6 @@
 // operator-ctrl.go
 package expr
 
-import (
-	"git.portale-stac.it/go-pkg/expr/kern"
-)
-
 //-------- export all term
 
 func newExportAllTerm(tk *Token) (inst *term) {
@@ -20,8 +16,8 @@ func newExportAllTerm(tk *Token) (inst *term) {
 	}
 }
 
-func evalExportAll(ctx kern.ExprContext, opTerm *term) (v any, err error) {
-	CtrlEnable(ctx, kern.ControlExportAll)
+func evalExportAll(ctx ExprContext, self *term) (v any, err error) {
+	enable(ctx, control_export_all)
 	return
 }
 

operator-default.go

@@ -1,128 +0,0 @@
-// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
-// All rights reserved.
-
-// operator-default.go
-package expr
-
-import (
-	"git.portale-stac.it/go-pkg/expr/kern"
-)
-
-//-------- default term
-
-func newDefaultTerm(tk *Token) (inst *term) {
-	return &term{
-		tk:       *tk,
-		children: make([]*term, 0, 2),
-		position: posInfix,
-		priority: priDefault,
-		evalFunc: evalDefault,
-	}
-}
-
-func evalDefault(ctx kern.ExprContext, opTerm *term) (v any, err error) {
-	var rightValue any
-
-	if err = opTerm.checkOperands(); err != nil {
-		return
-	}
-
-	leftTerm := opTerm.children[0]
-	if leftTerm.tk.Sym != SymVariable {
-		// err = leftTerm.Errorf("left operand of %q must be a variable", self.tk.source)
-		err = kern.ErrLeftOperandMustBeVariable(leftTerm, opTerm)
-		return
-	}
-
-	if leftValue, exists := ctx.GetVar(leftTerm.Source()); exists {
-		v = leftValue
-	} else if rightValue, err = opTerm.children[1].Compute(ctx); err == nil {
-		v = rightValue
-	}
-	return
-}
-
-//-------- alternate term
-
-func newAlternateTerm(tk *Token) (inst *term) {
-	return &term{
-		tk:       *tk,
-		children: make([]*term, 0, 2),
-		position: posInfix,
-		priority: priDefault,
-		evalFunc: evalAlternate,
-	}
-}
-
-func evalAlternate(ctx kern.ExprContext, opTerm *term) (v any, err error) {
-	var rightValue any
-
-	if err = opTerm.checkOperands(); err != nil {
-		return
-	}
-
-	leftTerm := opTerm.children[0]
-	if leftTerm.tk.Sym != SymVariable {
-		// err = leftTerm.Errorf("left operand of %q must be a variable", self.tk.source)
-		err = kern.ErrLeftOperandMustBeVariable(leftTerm, opTerm)
-		return
-	}
-
-	if leftValue, exists := ctx.GetVar(leftTerm.Source()); exists && leftValue != nil {
-		if rightValue, err = opTerm.children[1].Compute(ctx); err == nil {
-			v = rightValue
-		}
-	} else {
-		v = leftValue
-	}
-	return
-}
-
-//-------- default assign term
-
-func newDefaultAssignTerm(tk *Token) (inst *term) {
-	return &term{
-		tk:       *tk,
-		children: make([]*term, 0, 2),
-		position: posInfix,
-		priority: priDefault,
-		evalFunc: evalAssignDefault,
-	}
-}
-
-func evalAssignDefault(ctx kern.ExprContext, opTerm *term) (v any, err error) {
-	var rightValue any
-
-	if err = opTerm.checkOperands(); err != nil {
-		return
-	}
-
-	leftTerm := opTerm.children[0]
-	if leftTerm.tk.Sym != SymVariable {
-		// err = leftTerm.Errorf("left operand of %q must be a variable", self.tk.source)
-		err = kern.ErrLeftOperandMustBeVariable(leftTerm, opTerm)
-		return
-	}
-
-	if leftValue, exists := ctx.GetVar(leftTerm.Source()); exists {
-		v = leftValue
-	} else if rightValue, err = opTerm.children[1].Compute(ctx); err == nil {
-		if functor, ok := rightValue.(kern.Functor); ok {
-			//ctx.RegisterFunc(leftTerm.source(), functor, 0, -1)
-			ctx.RegisterFunc(leftTerm.Source(), functor, kern.TypeAny, []kern.ExprFuncParam{
-				NewFuncParamFlag(kern.ParamValue, PfDefault|PfRepeat),
-			})
-		} else {
-			v = rightValue
-			ctx.UnsafeSetVar(leftTerm.Source(), rightValue)
-		}
-	}
-	return
-}
-
-// init
-func init() {
-	registerTermConstructor(SymDoubleQuestion, newDefaultTerm)
-	registerTermConstructor(SymQuestionEqual, newDefaultAssignTerm)
-	registerTermConstructor(SymQuestionExclam, newAlternateTerm)
-}

operator-digest.go

@@ -1,72 +0,0 @@
-// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
-// All rights reserved.
-
-// operator-digest.go
-package expr
-
-import (
-	"fmt"
-	"io"
-
-	"git.portale-stac.it/go-pkg/expr/kern"
-)
-
-//-------- digest term
-
-func newDigestTerm(tk *Token) (inst *term) {
-	return &term{
-		tk:       *tk,
-		children: make([]*term, 0, 2),
-		position: posInfix,
-		priority: priIterOp,
-		evalFunc: evalDigest,
-	}
-}
-
-func evalDigest(ctx kern.ExprContext, opTerm *term) (v any, err error) {
-	var leftValue, rightValue any
-	var it kern.Iterator
-	var item, lastValue any
-
-	if err = opTerm.checkOperands(); err != nil {
-		return
-	}
-
-	if leftValue, err = opTerm.children[0].Compute(ctx); err != nil {
-		return
-	}
-
-	if it, err = NewIterator(leftValue); err != nil {
-		return nil, fmt.Errorf("left operand of DIGEST must be an iterable data-source; got %s", kern.TypeName(leftValue))
-	}
-
-	lastValue = nil
-	for item, err = it.Next(); err == nil; item, err = it.Next() {
-		ctx.SetVar("_", item)
-		ctx.SetVar("__", it.Index())
-		ctx.SetVar("_#", it.Count())
-		if rightValue, err = opTerm.children[1].Compute(ctx); err == nil {
-			if rightValue == nil {
-				break
-			} else {
-				lastValue = rightValue
-			}
-		}
-		ctx.DeleteVar("_#")
-		ctx.DeleteVar("__")
-		ctx.DeleteVar("_")
-		if err != nil {
-			break
-		}
-	}
-	if err == io.EOF {
-		err = nil
-	}
-	v = lastValue
-	return
-}
-
-// init
-func init() {
-	registerTermConstructor(SymKwDigest, newDigestTerm)
-}

operator-dot.go

@@ -4,10 +4,6 @@
 // operator-dot.go
 package expr
 
-import (
-	"git.portale-stac.it/go-pkg/expr/kern"
-)
-
 // -------- dot term
 func newDotTerm(tk *Token) (inst *term) {
 	return &term{
@@ -19,51 +15,42 @@ func newDotTerm(tk *Token) (inst *term) {
 	}
 }
 
-func evalDot(ctx kern.ExprContext, opTerm *term) (v any, err error) {
+func evalDot(ctx ExprContext, self *term) (v any, err error) {
 	var leftValue, rightValue any
 
-	if err = opTerm.checkOperands(); err != nil {
-		return
-	}
-	if leftValue, err = opTerm.children[0].Compute(ctx); err != nil {
+	if leftValue, rightValue, err = self.evalInfix(ctx); err != nil {
 		return
 	}
 
-	indexTerm := opTerm.children[1]
+	indexTerm := self.children[1]
+	if !isInteger(rightValue) {
+		err = indexTerm.Errorf("index expression must be integer, got %T", rightValue)
+		return
+	}
 
-	switch unboxedValue := leftValue.(type) {
-	case kern.ExtIterator:
-		if indexTerm.symbol() == SymVariable /*|| indexTerm.symbol() == SymString */ {
-			opName := indexTerm.Source()
-			if unboxedValue.HasOperation(opName) {
-				v, err = unboxedValue.CallOperation(opName, map[string]any{})
+	index64, _ := rightValue.(int64)
+	index := int(index64)
+
+	if isList(leftValue) {
+		list, _ := leftValue.([]any)
+		if index >= 0 && index < len(list) {
+			v = list[index]
+		} else if index >= -len(list) {
+			v = list[len(list)+index]
 		} else {
-				err = indexTerm.Errorf("this iterator do not support the %q command", opName)
-				v = false
+			err = indexTerm.Errorf("index %v out of bounds", index)
+		}
+	} else if isString(leftValue) {
+		s, _ := leftValue.(string)
+		if index >= 0 && index < len(s) {
+			v = string(s[index])
+		} else if index >= -len(s) {
+			v = string(s[len(s)+index])
+		} else {
+			err = indexTerm.Errorf("index %v out of bounds", index)
 		}
 	} else {
-			err = indexTerm.tk.ErrorExpectedGot("identifier")
-		}
-	case *kern.DictType:
-		var ok bool
-		s := opTerm.children[1].symbol()
-		if s == SymVariable || s == SymString {
-			src := opTerm.children[1].Source()
-			if len(src) > 1 && src[0] == '"' && src[len(src)-1] == '"' {
-				src = src[1 : len(src)-1]
-			}
-			if v, ok = unboxedValue.GetItem(src); !ok {
-				err = opTerm.errKeyNotFound(src)
-			}
-		} else if rightValue, err = opTerm.children[1].Compute(ctx); err == nil {
-			if v, ok = unboxedValue.GetItem(rightValue); !ok {
-				err = opTerm.errKeyNotFound(rightValue)
-			}
-		}
-	default:
-		if rightValue, err = opTerm.children[1].Compute(ctx); err == nil {
-			err = opTerm.errIncompatibleTypes(leftValue, rightValue)
-		}
+		err = self.errIncompatibleTypes(leftValue, rightValue)
 	}
 	return
 }

operator-fact.go

@@ -4,11 +4,7 @@
 // operator-fact.go
 package expr
 
-import (
-	"fmt"
-
-	"git.portale-stac.it/go-pkg/expr/kern"
-)
+import "fmt"
 
 //-------- fact term
 
@@ -22,14 +18,14 @@ func newFactTerm(tk *Token) (inst *term) {
 	}
 }
 
-func evalFact(ctx kern.ExprContext, opTerm *term) (v any, err error) {
+func evalFact(ctx ExprContext, self *term) (v any, err error) {
 	var leftValue any
 
-	if leftValue, err = opTerm.evalPrefix(ctx); err != nil {
+	if leftValue, err = self.evalPrefix(ctx); err != nil {
 		return
 	}
 
-	if kern.IsInteger(leftValue) {
+	if isInteger(leftValue) {
 		if i, _ := leftValue.(int64); i >= 0 {
 			f := int64(1)
 			for k := int64(1); k <= i; k++ {
@@ -40,7 +36,7 @@ func evalFact(ctx kern.ExprContext, opTerm *term) (v any, err error) {
 			err = fmt.Errorf("factorial of a negative integer (%d) is not allowed", i)
 		}
 	} else {
-		err = opTerm.errIncompatiblePrefixPostfixType(leftValue)
+		err = self.errIncompatibleType(leftValue)
 	}
 	return
 }

operator-filter.go

@@ -1,74 +0,0 @@
-// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
-// All rights reserved.
-
-// operator-filter.go
-package expr
-
-import (
-	"fmt"
-	"io"
-
-	"git.portale-stac.it/go-pkg/expr/kern"
-)
-
-//-------- map term
-
-func newFilterTerm(tk *Token) (inst *term) {
-	return &term{
-		tk:       *tk,
-		children: make([]*term, 0, 2),
-		position: posInfix,
-		priority: priIterOp,
-		evalFunc: evalFilter,
-	}
-}
-
-func evalFilter(ctx kern.ExprContext, opTerm *term) (v any, err error) {
-	var leftValue, rightValue any
-	var it kern.Iterator
-	var item any
-
-	if err = opTerm.checkOperands(); err != nil {
-		return
-	}
-
-	if leftValue, err = opTerm.children[0].Compute(ctx); err != nil {
-		return
-	}
-
-	if it, err = NewIterator(leftValue); err != nil {
-		return nil, fmt.Errorf("left operand of FILTER must be an iterable data-source; got %s", kern.TypeName(leftValue))
-	}
-
-	values := kern.NewListA()
-	for item, err = it.Next(); err == nil; item, err = it.Next() {
-		ctx.SetVar("_", item)
-		ctx.SetVar("__", it.Index())
-		ctx.SetVar("_#", it.Count())
-		if rightValue, err = opTerm.children[1].Compute(ctx); err == nil {
-			if success, valid := kern.ToBool(rightValue); valid {
-				if success {
-					values.AppendItem(item)
-				}
-			} else {
-				err = fmt.Errorf("filter expression must return a boolean or a castable to boolean, got %v [%T]", rightValue, rightValue)
-			}
-		}
-		ctx.DeleteVar("_#")
-		ctx.DeleteVar("__")
-		ctx.DeleteVar("_")
-		if err != nil {
-			break
-		}
-	}
-	if err == io.EOF {
-		err = nil
-	}
-	v = values
-	return
-}
-
-// init
-func init() {
-	registerTermConstructor(SymKwFilter, newFilterTerm)
-}

operator-fraction.go

@@ -1,75 +0,0 @@
-// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
-// All rights reserved.
-
-// operand-fraction.go
-package expr
-
-//https://www.youmath.it/lezioni/algebra-elementare/lezioni-di-algebra-e-aritmetica-per-scuole-medie/553-dalle-frazioni-a-numeri-decimali.html
-
-import (
-	"fmt"
-
-	"git.portale-stac.it/go-pkg/expr/kern"
-)
-
-// -------- fraction term
-func newFractionTerm(tk *Token) *term {
-	return &term{
-		tk:       *tk,
-		parent:   nil,
-		children: make([]*term, 0, 2),
-		position: posInfix,
-		priority: priFraction,
-		evalFunc: evalFraction,
-	}
-}
-
-// -------- eval func
-func evalFraction(ctx kern.ExprContext, opTerm *term) (v any, err error) {
-	var numValue, denValue any
-	var num, den int64
-	var ok bool
-
-	if numValue, denValue, err = opTerm.evalInfix(ctx); err != nil {
-		return
-	}
-	if num, ok = numValue.(int64); !ok {
-		err = fmt.Errorf("numerator must be integer, got %T (%v)", numValue, numValue)
-		return
-	}
-	if den, ok = denValue.(int64); !ok {
-		err = fmt.Errorf("denominator must be integer, got %T (%v)", denValue, denValue)
-		return
-	}
-	if den == 0 {
-		err = opTerm.errDivisionByZero()
-		return
-	}
-
-	if den < 0 {
-		den = -den
-		num = -num
-	}
-	if num != 0 {
-		if g := kern.Gcd(num, den); g != 1 {
-			num = num / g
-			den = den / g
-		}
-		if den == 1 {
-			v = num
-		} else {
-			// v = &expr.FractionType{num, den}
-			v = kern.NewFraction(num, den)
-		}
-	} else {
-		// v = &FractionType{0, den}
-		v = kern.NewFraction(0, den)
-	}
-	return
-}
-
-// init
-func init() {
-	// registerTermConstructor(SymVertBar, newFractionTerm)
-	registerTermConstructor(SymColon, newFractionTerm)
-}

operator-groupby.go

@@ -1,105 +0,0 @@
-// Copyright (c) 2024-2026 Celestino Amoroso (celestino.amoroso@gmail.com).
-// All rights reserved.
-
-// operator-groupby.go
-package expr
-
-import (
-	"fmt"
-	"io"
-	"strconv"
-
-	"git.portale-stac.it/go-pkg/expr/kern"
-)
-
-//-------- group by term
-
-func newGroupByTerm(tk *Token) (inst *term) {
-	return &term{
-		tk:       *tk,
-		children: make([]*term, 0, 2),
-		position: posInfix,
-		priority: priIterOp,
-		evalFunc: evalGroupBy,
-	}
-}
-
-func evalGroupBy(ctx kern.ExprContext, opTerm *term) (v any, err error) {
-	var leftValue, rightValue any
-	var it kern.Iterator
-	var item any
-	var sKey string
-	var keyByIndex bool
-
-	if err = opTerm.checkOperands(); err != nil {
-		return
-	}
-
-	if leftValue, err = opTerm.children[0].Compute(ctx); err != nil {
-		return
-	}
-
-	if it, err = NewIterator(leftValue); err != nil {
-		return nil, fmt.Errorf("left operand of MAP must be an iterable data-source; got %s", kern.TypeName(leftValue))
-	}
-
-	rightTk := opTerm.children[1].tk
-	if rightTk.IsSymbol(SymVariable) && rightTk.source == "__" {
-		keyByIndex = true
-	} else if rightValue, err = opTerm.children[1].Compute(ctx); err != nil {
-		return
-	} else if kern.IsString(rightValue) {
-		sKey = rightValue.(string)
-	} else {
-		return nil, fmt.Errorf("right operand of GROUPBY must be a string or identifier '__'; got %s", kern.TypeName(rightValue))
-	}
-
-	values := kern.MakeDict()
-	for item, err = it.Next(); err == nil; item, err = it.Next() {
-		ctx.SetVar("_", item)
-		ctx.SetVar("__", it.Index())
-		ctx.SetVar("_#", it.Count())
-
-		var sItemKey string
-
-		if d, ok := item.(*kern.DictType); ok {
-			if keyByIndex || len(sKey) == 0 {
-				sItemKey = strconv.Itoa(int(it.Index()))
-			} else if d.HasKey(sKey) {
-				if keyValue, exists := d.GetItem(sKey); exists {
-					sItemKey = fmt.Sprintf("%v", keyValue)
-				} else {
-					sItemKey = "_"
-				}
-			} else {
-				sItemKey = "_"
-			}
-		} else {
-			sItemKey = strconv.Itoa(int(it.Index()))
-		}
-
-		var ls *kern.ListType
-		if lsAny, exists := values.GetItem(sItemKey); exists && lsAny != nil {
-			ls = lsAny.(*kern.ListType)
-		}
-		if ls == nil {
-			ls = kern.NewListA()
-		}
-		ls.AppendItem(item)
-		values.SetItem(sItemKey, ls)
-
-		ctx.DeleteVar("_#")
-		ctx.DeleteVar("__")
-		ctx.DeleteVar("_")
-	}
-	if err == io.EOF {
-		err = nil
-	}
-	v = values
-	return
-}
-
-// init
-func init() {
-	registerTermConstructor(SymKwGroupBy, newGroupByTerm)
-}

operator-in.go

@@ -1,50 +0,0 @@
-// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
-// All rights reserved.
-
-// operator-in.go
-package expr
-
-import (
-	"git.portale-stac.it/go-pkg/expr/kern"
-)
-
-//-------- in term
-
-func newInTerm(tk *Token) (inst *term) {
-	return &term{
-		tk:       *tk,
-		children: make([]*term, 0, 2),
-		position: posInfix,
-		priority: priRelational,
-		evalFunc: evalIn,
-	}
-}
-
-// func hasKey(d map[any]any, target any) (ok bool) {
-// 	_, ok = d[target]
-// 	return
-// }
-
-func evalIn(ctx kern.ExprContext, opTerm *term) (v any, err error) {
-	var leftValue, rightValue any
-
-	if leftValue, rightValue, err = opTerm.evalInfix(ctx); err != nil {
-		return
-	}
-
-	if kern.IsList(rightValue) {
-		list, _ := rightValue.(*kern.ListType)
-		v = list.IndexDeepSameCmp(leftValue) >= 0
-	} else if kern.IsDict(rightValue) {
-		dict, _ := rightValue.(*kern.DictType)
-		v = dict.HasKey(leftValue)
-	} else {
-		err = opTerm.errIncompatibleTypes(leftValue, rightValue)
-	}
-	return
-}
-
-// init
-func init() {
-	registerTermConstructor(SymKwIn, newInTerm)
-}

operator-include.go

@@ -1,64 +0,0 @@
-// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
-// All rights reserved.
-
-// operator-include.go
-package expr
-
-import (
-	"git.portale-stac.it/go-pkg/expr/kern"
-)
-
-//-------- include term
-
-func newIncludeTerm(tk *Token) (inst *term) {
-	return &term{
-		tk:       *tk,
-		children: make([]*term, 0, 1),
-		position: posPrefix,
-		priority: priSign,
-		evalFunc: evalInclude,
-	}
-}
-
-func evalInclude(ctx kern.ExprContext, opTerm *term) (v any, err error) {
-	var childValue any
-
-	if childValue, err = opTerm.evalPrefix(ctx); err != nil {
-		return
-	}
-
-	count := 0
-	if kern.IsList(childValue) {
-		list, _ := childValue.(*kern.ListType)
-		for i, filePathSpec := range *list {
-			if filePath, ok := filePathSpec.(string); ok {
-				if v, err = EvalFile(ctx, filePath); err == nil {
-					count++
-				} else {
-					err = opTerm.Errorf("can't load file %q", filePath)
-					break
-				}
-			} else {
-				err = opTerm.Errorf("expected string at item nr %d, got %T", i+1, filePathSpec)
-				break
-			}
-		}
-	} else if kern.IsString(childValue) {
-		filePath, _ := childValue.(string)
-		if v, err = EvalFile(ctx, filePath); err == nil {
-			count++
-		}
-	} else {
-		err = opTerm.errIncompatiblePrefixPostfixType(childValue)
-	}
-	if err != nil {
-		//v = count
-		v = nil
-	}
-	return
-}
-
-// init
-func init() {
-	registerTermConstructor(SymKwInclude, newIncludeTerm)
-}

operator-index.go

@@ -1,142 +0,0 @@
-// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
-// All rights reserved.
-
-// operator-index.go
-package expr
-
-import (
-	"git.portale-stac.it/go-pkg/expr/kern"
-)
-
-// -------- index term
-func newIndexTerm(tk *Token) (inst *term) {
-	return &term{
-		tk:       *tk,
-		children: make([]*term, 0, 2),
-		position: posInfix,
-		priority: priDot,
-		evalFunc: evalIndex,
-	}
-}
-
-func verifyKey(indexList *kern.ListType) (index any, err error) {
-	index = (*indexList)[0]
-	return
-}
-
-func verifyIndex(indexTerm *term, indexList *kern.ListType, maxValue int) (index int, err error) {
-	var v int
-
-	if v, err = kern.ToGoInt((*indexList)[0], "index expression"); err == nil {
-		if v < 0 && v >= -maxValue {
-			v = maxValue + v
-		}
-		if v >= 0 && v < maxValue {
-			index = v
-		} else {
-			err = indexTerm.Errorf("index %d out of bounds", v)
-		}
-	}
-	return
-}
-
-func verifyRange(indexTerm *term, indexList *kern.ListType, maxValue int) (startIndex, endIndex int, err error) {
-	v, _ := ((*indexList)[0]).(*intPair)
-	startIndex = v.a
-	endIndex = v.b
-	if endIndex == kern.ConstLastIndex {
-		endIndex = maxValue
-	}
-	if startIndex < 0 && startIndex >= -maxValue {
-		startIndex = maxValue + startIndex
-	}
-	if endIndex < 0 && endIndex >= -maxValue {
-		endIndex = maxValue + endIndex
-	}
-	if startIndex < 0 || startIndex > maxValue {
-		err = indexTerm.Errorf("range start-index %d is out of bounds", startIndex)
-	} else if endIndex < 0 || endIndex > maxValue {
-		err = indexTerm.Errorf("range end-index %d is out of bounds", endIndex)
-	} else if startIndex > endIndex {
-		err = indexTerm.Errorf("range start-index %d must not be greater than end-index %d", startIndex, endIndex)
-	}
-	return
-}
-
-func evalIndex(ctx kern.ExprContext, opTerm *term) (v any, err error) {
-	var leftValue, rightValue any
-	var indexList *kern.ListType
-	var ok bool
-
-	if leftValue, rightValue, err = opTerm.evalInfix(ctx); err != nil {
-		return
-	}
-
-	indexTerm := opTerm.children[1]
-	if indexList, ok = rightValue.(*kern.ListType); !ok {
-		err = opTerm.Errorf("invalid index expression")
-		return
-	} else if len(*indexList) != 1 {
-		err = indexTerm.Errorf("one index only is allowed")
-		return
-	}
-
-	if kern.IsInteger((*indexList)[0]) {
-		switch unboxedValue := leftValue.(type) {
-		case *kern.ListType:
-			var index int
-			if index, err = verifyIndex(indexTerm, indexList, len(*unboxedValue)); err == nil {
-				v = (*unboxedValue)[index]
-			}
-		case string:
-			var index int
-			if index, err = verifyIndex(indexTerm, indexList, len(unboxedValue)); err == nil {
-				v = string(unboxedValue[index])
-			}
-		case *kern.DictType:
-			v, err = getDictItem(unboxedValue, indexTerm, indexList, rightValue)
-		default:
-			err = opTerm.errIncompatibleTypes(leftValue, rightValue)
-		}
-	} else if isIntPair((*indexList)[0]) {
-		switch unboxedValue := leftValue.(type) {
-		case *kern.ListType:
-			var start, end int
-			if start, end, err = verifyRange(indexTerm, indexList, len(*unboxedValue)); err == nil {
-				sublist := kern.ListType((*unboxedValue)[start:end])
-				v = &sublist
-			}
-		case string:
-			var start, end int
-			if start, end, err = verifyRange(indexTerm, indexList, len(unboxedValue)); err == nil {
-				v = unboxedValue[start:end]
-			}
-		default:
-			err = opTerm.errIncompatibleTypes(leftValue, rightValue)
-		}
-	} else if kern.IsDict(leftValue) {
-		d := leftValue.(*kern.DictType)
-		v, err = getDictItem(d, indexTerm, indexList, rightValue)
-	} else {
-		rightChild := opTerm.children[1]
-		err = rightChild.Errorf("invalid index type: %v", (*indexList)[0])
-	}
-	return
-}
-
-func getDictItem(d *kern.DictType, indexTerm *term, indexList *kern.ListType, rightValue any) (v any, err error) {
-	var ok bool
-	var indexValue any
-
-	if indexValue, err = verifyKey(indexList); err == nil {
-		if v, ok = (*d)[indexValue]; !ok {
-			err = indexTerm.Errorf("key %v does not belong to the dictionary", rightValue)
-		}
-	}
-	return
-}
-
-// init
-func init() {
-	registerTermConstructor(SymIndex, newIndexTerm)
-}

operator-insert.go

@@ -4,19 +4,15 @@
 // operator-insert.go
 package expr
 
-import (
-	"git.portale-stac.it/go-pkg/expr/kern"
-)
+//-------- insert term
 
-//-------- prepend term
-
-func newPrependTerm(tk *Token) (inst *term) {
+func newInsertTerm(tk *Token) (inst *term) {
 	return &term{
 		tk:       *tk,
 		children: make([]*term, 0, 2),
 		position: posInfix,
-		priority: priInsert,
-		evalFunc: evalPrepend,
+		priority: priAssign,
+		evalFunc: evalInsert,
 	}
 }
 
@@ -25,71 +21,45 @@ func newAppendTerm(tk *Token) (inst *term) {
 		tk:       *tk,
 		children: make([]*term, 0, 2),
 		position: posInfix,
-		priority: priInsert,
+		priority: priAssign,
 		evalFunc: evalAppend,
 	}
 }
 
-func evalPrepend(ctx kern.ExprContext, opTerm *term) (v any, err error) {
+func evalInsert(ctx ExprContext, self *term) (v any, err error) {
 	var leftValue, rightValue any
 
-	if leftValue, rightValue, err = opTerm.evalInfix(ctx); err != nil {
+	if leftValue, rightValue, err = self.evalInfix(ctx); err != nil {
 		return
 	}
 
-	if kern.IsList(rightValue) {
-		list, _ := rightValue.(*kern.ListType)
-		newList := append(kern.ListType{leftValue}, *list...)
-		v = &newList
-		if opTerm.children[1].symbol() == SymVariable {
-			ctx.UnsafeSetVar(opTerm.children[1].Source(), v)
-		}
+	if isList(rightValue) {
+		list, _ := rightValue.([]any)
+		v = append([]any{leftValue}, list...)
 	} else {
-		err = opTerm.errIncompatibleTypes(leftValue, rightValue)
+		err = self.errIncompatibleTypes(leftValue, rightValue)
 	}
 	return
 }
 
-func evalAppend(ctx kern.ExprContext, opTerm *term) (v any, err error) {
+func evalAppend(ctx ExprContext, self *term) (v any, err error) {
 	var leftValue, rightValue any
 
-	if leftValue, rightValue, err = opTerm.evalInfix(ctx); err != nil {
+	if leftValue, rightValue, err = self.evalInfix(ctx); err != nil {
 		return
 	}
 
-	if kern.IsList(leftValue) {
-		list, _ := leftValue.(*kern.ListType)
-		newList := append(*list, rightValue)
-		v = &newList
-		if opTerm.children[0].symbol() == SymVariable {
-			ctx.UnsafeSetVar(opTerm.children[0].Source(), v)
-		}
+	if isList(leftValue) {
+		list, _ := leftValue.([]any)
+		v = append(list, rightValue)
 	} else {
-		err = opTerm.errIncompatibleTypes(leftValue, rightValue)
+		err = self.errIncompatibleTypes(leftValue, rightValue)
 	}
 	return
 }
 
-// func evalAssignAppend(ctx ExprContext, self *term) (v any, err error) {
-// 	var leftValue, rightValue any
-
-// 	if leftValue, rightValue, err = self.evalInfix(ctx); err != nil {
-// 		return
-// 	}
-
-// 	if IsList(leftValue) {
-// 		list, _ := leftValue.(*ListType)
-// 		newList := append(*list, rightValue)
-// 		v = &newList
-// 		if
-// 	} else {
-// 		err = self.errIncompatibleTypes(leftValue, rightValue)
-// 	}
-// 	return
-// }
-
 // init
 func init() {
-	registerTermConstructor(SymPlusGreater, newPrependTerm)
-	registerTermConstructor(SymLessPlus, newAppendTerm)
+	registerTermConstructor(SymInsert, newInsertTerm)
+	registerTermConstructor(SymAppend, newAppendTerm)
 }

operator-iter-value.go

@@ -1,42 +0,0 @@
-// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
-// All rights reserved.
-
-// operator-iter-value.go
-package expr
-
-import (
-	"git.portale-stac.it/go-pkg/expr/kern"
-)
-
-//-------- iter value term
-
-func newIterValueTerm(tk *Token) (inst *term) {
-	return &term{
-		tk:       *tk,
-		children: make([]*term, 0, 1),
-		position: posPrefix,
-		priority: priDereference,
-		evalFunc: evalIterValue,
-	}
-}
-
-func evalIterValue(ctx kern.ExprContext, opTerm *term) (v any, err error) {
-	var childValue any
-
-	if childValue, err = opTerm.evalPrefix(ctx); err != nil {
-		return
-	}
-
-	if it, ok := childValue.(kern.Iterator); ok {
-		v, err = it.Current()
-	} else {
-		err = opTerm.errIncompatiblePrefixPostfixType(childValue)
-	}
-	return
-}
-
-// init
-func init() {
-	//	registerTermConstructor(SymOpenClosedRound, newIterValueTerm)
-	registerTermConstructor(SymDereference, newIterValueTerm)
-}

operator-join.go

@@ -1,67 +0,0 @@
-// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
-// All rights reserved.
-
-// operator-join.go
-package expr
-
-import (
-	"fmt"
-	"io"
-
-	"git.portale-stac.it/go-pkg/expr/kern"
-)
-
-//-------- join term
-
-func newJoinTerm(tk *Token) (inst *term) {
-	return &term{
-		tk:       *tk,
-		children: make([]*term, 0, 2),
-		position: posInfix,
-		priority: priIterOp,
-		evalFunc: evalJoin,
-	}
-}
-
-func evalJoin(ctx kern.ExprContext, opTerm *term) (v any, err error) {
-	var leftValue, rightValue any
-	var itLeft, itRight kern.Iterator
-	var item any
-
-	if err = opTerm.checkOperands(); err != nil {
-		return
-	}
-
-	if leftValue, err = opTerm.children[0].Compute(ctx); err != nil {
-		return
-	}
-
-	if rightValue, err = opTerm.children[1].Compute(ctx); err != nil {
-		return
-	}
-
-	if itLeft, err = NewIterator(leftValue); err != nil {
-		return nil, fmt.Errorf("left operand of JOIN must be an iterable data-source; got %s", kern.TypeName(leftValue))
-	}
-
-	if itRight, err = NewIterator(rightValue); err != nil {
-		return nil, fmt.Errorf("right operand of JOIN must be an iterable data-source; got %s", kern.TypeName(rightValue))
-	}
-
-	values := kern.NewListA()
-	for _, it := range []kern.Iterator{itLeft, itRight} {
-		for item, err = it.Next(); err == nil; item, err = it.Next() {
-			values.AppendItem(item)
-		}
-	}
-	if err == io.EOF {
-		err = nil
-	}
-	v = values
-	return
-}
-
-// init
-func init() {
-	registerTermConstructor(SymKwJoin, newJoinTerm)
-}

operator-length.go

@@ -4,10 +4,6 @@
 // operator-length.go
 package expr
 
-import (
-	"git.portale-stac.it/go-pkg/expr/kern"
-)
-
 //-------- length term
 
 func newLengthTerm(tk *Token) (inst *term) {
@@ -20,32 +16,24 @@ func newLengthTerm(tk *Token) (inst *term) {
 	}
 }
 
-func evalLength(ctx kern.ExprContext, opTerm *term) (v any, err error) {
-	var childValue any
+func evalLength(ctx ExprContext, self *term) (v any, err error) {
+	var rightValue any
 
-	if childValue, err = opTerm.evalPrefix(ctx); err != nil {
+	if rightValue, err = self.evalPrefix(ctx); err != nil {
 		return
 	}
 
-	if kern.IsList(childValue) {
-		ls, _ := childValue.(*kern.ListType)
-		v = int64(len(*ls))
-	} else if kern.IsString(childValue) {
-		s, _ := childValue.(string)
-		v = int64(len(s))
-	} else if kern.IsDict(childValue) {
-		m, _ := childValue.(*kern.DictType)
-		v = int64(len(*m))
-	} else if it, ok := childValue.(kern.Iterator); ok {
-		v = int64(it.Count())
-		// if extIt, ok := childValue.(ExtIterator); ok && extIt.HasOperation(CountName) {
-		// 	count, _ := extIt.CallOperation(CountName, nil)
-		// 	v, _ = ToGoInt(count, "")
+	if isList(rightValue) {
+		list, _ := rightValue.([]any)
+		v = len(list)
+	} else if isString(rightValue) {
+		s, _ := rightValue.(string)
+		v = len(s)
 		// } else {
-		// 	v = int64(it.Index() + 1)
+		// 	v = 1
 		// }
 	} else {
-		err = opTerm.errIncompatiblePrefixPostfixType(childValue)
+		err = self.errIncompatibleType(rightValue)
 	}
 	return
 }

operator-map.go

@@ -1,70 +0,0 @@
-// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
-// All rights reserved.
-
-// operator-map.go
-package expr
-
-import (
-	"fmt"
-	"io"
-
-	"git.portale-stac.it/go-pkg/expr/kern"
-)
-
-//-------- map term
-
-func newMapTerm(tk *Token) (inst *term) {
-	return &term{
-		tk:       *tk,
-		children: make([]*term, 0, 2),
-		position: posInfix,
-		priority: priIterOp,
-		evalFunc: evalMap,
-	}
-}
-
-func evalMap(ctx kern.ExprContext, opTerm *term) (v any, err error) {
-	var leftValue, rightValue any
-	var it kern.Iterator
-	var item any
-
-	if err = opTerm.checkOperands(); err != nil {
-		return
-	}
-
-	if leftValue, err = opTerm.children[0].Compute(ctx); err != nil {
-		return
-	}
-
-	if it, err = NewIterator(leftValue); err != nil {
-		return nil, fmt.Errorf("left operand of MAP must be an iterable data-source; got %s", kern.TypeName(leftValue))
-	}
-
-	values := kern.NewListA()
-	for item, err = it.Next(); err == nil; item, err = it.Next() {
-		ctx.SetVar("_", item)
-		ctx.SetVar("__", it.Index())
-		ctx.SetVar("_#", it.Count())
-		if rightValue, err = opTerm.children[1].Compute(ctx); err == nil {
-			values.AppendItem(rightValue)
-		}
-		ctx.DeleteVar("_#")
-		ctx.DeleteVar("__")
-		ctx.DeleteVar("_")
-		if err != nil {
-			break
-		}
-	}
-	if err == io.EOF {
-		err = nil
-	}
-	if err == nil {
-		v = values
-	}
-	return
-}
-
-// init
-func init() {
-	registerTermConstructor(SymKwMap, newMapTerm)
-}

operator-plugin.go

@@ -1,40 +0,0 @@
-// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
-// All rights reserved.
-
-// operator-plugin.go
-package expr
-
-import (
-	"git.portale-stac.it/go-pkg/expr/kern"
-)
-
-//-------- plugin term
-
-func newPluginTerm(tk *Token) (inst *term) {
-	return &term{
-		tk:       *tk,
-		children: make([]*term, 0, 1),
-		position: posPrefix,
-		priority: priSign,
-		evalFunc: evalPlugin,
-	}
-}
-
-func evalPlugin(ctx kern.ExprContext, opTerm *term) (v any, err error) {
-	var childValue any
-	var count int
-
-	if childValue, err = opTerm.evalPrefix(ctx); err != nil {
-		return
-	}
-
-	if count, err = importPluginFromSearchPath(ctx, childValue); err == nil {
-		v = int64(count)
-	}
-	return
-}
-
-// init
-func init() {
-	registerTermConstructor(SymKwPlugin, newPluginTerm)
-}

operator-post-inc-dec.go

@@ -1,97 +0,0 @@
-// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
-// All rights reserved.
-
-// operator-post-inc-dec.go
-package expr
-
-import (
-	"git.portale-stac.it/go-pkg/expr/kern"
-)
-
-// -------- post increment term
-
-func newPostIncTerm(tk *Token) *term {
-	return &term{
-		tk:       *tk,
-		parent:   nil,
-		children: make([]*term, 0, 1),
-		position: posPostfix,
-		priority: priIncDec,
-		evalFunc: evalPostInc,
-	}
-}
-
-func evalPostInc(ctx kern.ExprContext, opTerm *term) (v any, err error) {
-	var childValue any
-	if childValue, err = opTerm.evalPrefix(ctx); err != nil {
-		return
-	}
-
-	if it, ok := childValue.(kern.Iterator); ok {
-		var namePrefix string
-		v, err = it.Next()
-
-		if opTerm.children[0].symbol() == SymVariable {
-			namePrefix = opTerm.children[0].Source()
-		}
-		ctx.UnsafeSetVar(namePrefix+"_index", it.Index())
-		if c, err1 := it.Current(); err1 == nil {
-			ctx.UnsafeSetVar(namePrefix+"_current", c)
-		}
-
-		if it.HasOperation(kern.KeyName) {
-			if k, err1 := it.CallOperation(kern.KeyName, nil); err1 == nil {
-				ctx.UnsafeSetVar(namePrefix+"_key", k)
-			}
-		}
-		if it.HasOperation(kern.ValueName) {
-			if v1, err1 := it.CallOperation(kern.ValueName, nil); err1 == nil {
-				ctx.UnsafeSetVar(namePrefix+"_value", v1)
-			}
-		}
-	} else if kern.IsInteger(childValue) && opTerm.children[0].symbol() == SymVariable {
-		v = childValue
-		i, _ := childValue.(int64)
-		ctx.SetVar(opTerm.children[0].Source(), i+1)
-	} else {
-		err = opTerm.errIncompatiblePrefixPostfixType(childValue)
-	}
-	return
-}
-
-// -------- post decrement term
-
-func newPostDecTerm(tk *Token) *term {
-	return &term{
-		tk:       *tk,
-		parent:   nil,
-		children: make([]*term, 0, 1),
-		position: posPostfix,
-		priority: priIncDec,
-		evalFunc: evalPostDec,
-	}
-}
-
-func evalPostDec(ctx kern.ExprContext, opTerm *term) (v any, err error) {
-	var childValue any
-	if childValue, err = opTerm.evalPrefix(ctx); err != nil {
-		return
-	}
-
-	/* if it, ok := childValue.(Iterator); ok {
-		v, err = it.Next()
-	} else  */if kern.IsInteger(childValue) && opTerm.children[0].symbol() == SymVariable {
-		v = childValue
-		i, _ := childValue.(int64)
-		ctx.SetVar(opTerm.children[0].Source(), i-1)
-	} else {
-		err = opTerm.errIncompatiblePrefixPostfixType(childValue)
-	}
-	return
-}
-
-// init
-func init() {
-	registerTermConstructor(SymDoublePlus, newPostIncTerm)
-	registerTermConstructor(SymDoubleMinus, newPostDecTerm)
-}