IsOptional() function of ExprFuncParam renamed as IdDefault(). A new IsOptional() function created to check if a param is optional without requiring a default value

context.go

@@ -16,6 +16,7 @@ type Functor interface {
 type ExprFuncParam interface {
 	Name() string
 	Type() string
+	IsDefault() bool
 	IsOptional() bool
 	IsRepeat() bool
 	DefaultValue() any
@@ -36,6 +37,8 @@ type ExprFunc interface {
 type ExprContext interface {
 	Clone() ExprContext
 	Merge(ctx ExprContext)
+	SetParent(ctx ExprContext)
+	GetParent() (ctx ExprContext)
 	GetVar(varName string) (value any, exists bool)
 	SetVar(varName string, value any)
 	UnsafeSetVar(varName string, value any)

func-base.go

@@ -177,7 +177,7 @@ func ImportBuiltinsFuncs(ctx ExprContext) {
 	ctx.RegisterFunc("dec", NewGolangFunctor(decFunc), TypeFloat, anyParams)
 	ctx.RegisterFunc("fract", NewGolangFunctor(fractFunc), TypeFraction, []ExprFuncParam{
 		NewFuncParam(paramValue),
-		NewFuncParamFlagDef("denominator", PfOptional, 1),
+		NewFuncParamFlagDef("denominator", PfDefault, 1),
 	})
 }
 

func-import.go

@@ -16,7 +16,7 @@ func importFunc(ctx ExprContext, name string, args []any) (result any, err error
 }
 
 func importAllFunc(ctx ExprContext, name string, args []any) (result any, err error) {
-	enable(ctx, control_export_all)
+	CtrlEnable(ctx, control_export_all)
 	return importGeneral(ctx, name, args)
 }
 
@@ -30,7 +30,8 @@ func importGeneral(ctx ExprContext, name string, args []any) (result any, err er
 }
 
 func addPresetImportDirs(ctx ExprContext, dirList []string) []string {
-	return addPresetDirs(ctx, ControlImportPath, dirList)
+	// return addPresetDirs(ctx, ControlImportPath, dirList)
+	return addSearchDirs(ctx, "sources", dirList)
 }
 
 func doImport(ctx ExprContext, name string, dirList []string, it Iterator) (result any, err error) {
@@ -49,9 +50,9 @@ func doImport(ctx ExprContext, name string, dirList []string, it Iterator) (resu
 			defer file.Close()
 			var expr *ast
 			scanner := NewScanner(file, DefaultTranslations())
-			parser := NewParser(ctx)
+			parser := NewParser()
 			if expr, err = parser.parseGeneral(scanner, true, true); err == nil {
-				result, err = expr.eval(ctx, false)
+				result, err = expr.Eval(ctx)
 			}
 			if err != nil {
 				break

func-math.go

@@ -168,11 +168,11 @@ func mulFunc(ctx ExprContext, name string, args []any) (result any, err error) {
 
 func ImportMathFuncs(ctx ExprContext) {
 	ctx.RegisterFunc("add", &golangFunctor{f: addFunc}, TypeNumber, []ExprFuncParam{
-		NewFuncParamFlagDef(paramValue, PfOptional|PfRepeat, int64(0)),
+		NewFuncParamFlagDef(paramValue, PfDefault|PfRepeat, int64(0)),
 	})
 
 	ctx.RegisterFunc("mul", &golangFunctor{f: mulFunc}, TypeNumber, []ExprFuncParam{
-		NewFuncParamFlagDef(paramValue, PfOptional|PfRepeat, int64(1)),
+		NewFuncParamFlagDef(paramValue, PfDefault|PfRepeat, int64(1)),
 	})
 }
 

func-os.go

@@ -198,11 +198,11 @@ func ImportOsFuncs(ctx ExprContext) {
 	})
 	ctx.RegisterFunc("writeFile", NewGolangFunctor(writeFileFunc), TypeInt, []ExprFuncParam{
 		NewFuncParam(TypeHandle),
-		NewFuncParamFlagDef(TypeItem, PfOptional|PfRepeat, ""),
+		NewFuncParamFlagDef(TypeItem, PfDefault|PfRepeat, ""),
 	})
 	ctx.RegisterFunc("readFile", NewGolangFunctor(readFileFunc), TypeString, []ExprFuncParam{
 		NewFuncParam(TypeHandle),
-		NewFuncParamFlagDef("limitCh", PfOptional, "\n"),
+		NewFuncParamFlagDef("limitCh", PfDefault, "\n"),
 	})
 	ctx.RegisterFunc("closeFile", NewGolangFunctor(closeFileFunc), TypeBoolean, []ExprFuncParam{
 		NewFuncParam(TypeHandle),

func-string.go

@@ -189,14 +189,14 @@ func ImportStringFuncs(ctx ExprContext) {
 
 	ctx.RegisterFunc("subStr", NewGolangFunctor(subStrFunc), TypeString, []ExprFuncParam{
 		NewFuncParam(paramSource),
-		NewFuncParamFlagDef(paramStart, PfOptional, int64(0)),
+		NewFuncParamFlagDef(paramStart, PfDefault, int64(0)),
-		NewFuncParamFlagDef(paramCount, PfOptional, int64(-1)),
+		NewFuncParamFlagDef(paramCount, PfDefault, int64(-1)),
 	})
 
 	ctx.RegisterFunc("splitStr", NewGolangFunctor(splitStrFunc), "list of "+TypeString, []ExprFuncParam{
 		NewFuncParam(paramSource),
-		NewFuncParamFlagDef(paramSeparator, PfOptional, ""),
+		NewFuncParamFlagDef(paramSeparator, PfDefault, ""),
-		NewFuncParamFlagDef(paramCount, PfOptional, int64(-1)),
+		NewFuncParamFlagDef(paramCount, PfDefault, int64(-1)),
 	})
 
 	ctx.RegisterFunc("trimStr", NewGolangFunctor(trimStrFunc), TypeString, []ExprFuncParam{

function.go

@@ -91,7 +91,7 @@ func (functor *exprFunctor) Invoke(ctx ExprContext, name string, args []any) (re
 			ctx.UnsafeSetVar(p.Name(), nil)
 		}
 	}
-	result, err = functor.expr.eval(ctx, false)
+	result, err = functor.expr.Eval(ctx)
 	return
 }
 
@@ -99,7 +99,8 @@ func (functor *exprFunctor) Invoke(ctx ExprContext, name string, args []any) (re
 type paramFlags uint16
 
 const (
-	PfOptional paramFlags = 1 << iota
+	PfDefault paramFlags = 1 << iota
+	PfOptional
 	PfRepeat
 )
 
@@ -126,7 +127,11 @@ func (param *funcParamInfo) Name() string {
 }
 
 func (param *funcParamInfo) Type() string {
-	return "any"
+	return TypeAny
+}
+
+func (param *funcParamInfo) IsDefault() bool {
+	return (param.flags & PfDefault) != 0
 }
 
 func (param *funcParamInfo) IsOptional() bool {
@@ -159,7 +164,7 @@ func newFuncInfo(name string, functor Functor, returnType string, params []ExprF
 			if maxArgs == -1 {
 				return nil, fmt.Errorf("no more params can be specified after the ellipsis symbol: %q", p.Name())
 			}
-			if p.IsOptional() {
+			if p.IsDefault() || p.IsOptional() {
 				maxArgs++
 			} else if maxArgs == minArgs {
 				minArgs++
@@ -207,7 +212,7 @@ func (info *funcInfo) ToString(opt FmtOpt) string {
 			}
 			sb.WriteString(p.Name())
 
-			if p.IsOptional() {
+			if p.IsDefault() {
 				sb.WriteByte('=')
 				if s, ok := p.DefaultValue().(string); ok {
 					sb.WriteByte('"')

operand-func.go

@@ -30,7 +30,7 @@ func checkFunctionCall(ctx ExprContext, name string, varParams *[]any) (err erro
 		}
 		for i, p := range info.Params() {
 			if i >= passedCount {
-				if !p.IsOptional() {
+				if !p.IsDefault() {
 					break
 				}
 				*varParams = append(*varParams, p.DefaultValue())
@@ -50,6 +50,7 @@ func checkFunctionCall(ctx ExprContext, name string, varParams *[]any) (err erro
 
 func evalFuncCall(parentCtx ExprContext, self *term) (v any, err error) {
 	ctx := cloneContext(parentCtx)
+	ctx.SetParent(parentCtx)
 	name, _ := self.tk.Value.(string)
 	params := make([]any, len(self.children), len(self.children)+5)
 	for i, tree := range self.children {
@@ -91,7 +92,7 @@ func evalFuncDef(ctx ExprContext, self *term) (v any, err error) {
 			var defValue any
 			flags := paramFlags(0)
 			if len(param.children) > 0 {
-				flags |= PfOptional
+				flags |= PfDefault
 				if defValue, err = param.children[0].compute(ctx); err != nil {
 					return
 				}

operator-coalesce.go

@@ -68,7 +68,7 @@ func evalAssignCoalesce(ctx ExprContext, self *term) (v any, err error) {
 		if functor, ok := rightValue.(Functor); ok {
 			//ctx.RegisterFunc(leftTerm.source(), functor, 0, -1)
 			ctx.RegisterFunc(leftTerm.source(), functor, TypeAny, []ExprFuncParam{
-				NewFuncParamFlag(paramValue, PfOptional|PfRepeat),
+				NewFuncParamFlag(paramValue, PfDefault|PfRepeat),
 			})
 		} else {
 			v = rightValue

operator-ctrl.go

@@ -17,7 +17,7 @@ func newExportAllTerm(tk *Token) (inst *term) {
 }
 
 func evalExportAll(ctx ExprContext, self *term) (v any, err error) {
-	enable(ctx, control_export_all)
+	CtrlEnable(ctx, control_export_all)
 	return
 }
 

operator-selector.go

@@ -19,17 +19,17 @@ func newSelectorTerm(tk *Token) (inst *term) {
 func trySelectorCase(ctx ExprContext, exprValue, caseSel any, caseIndex int) (match bool, selectedValue any, err error) {
 	caseData, _ := caseSel.(*selectorCase)
 	if caseData.filterList == nil {
-		selectedValue, err = caseData.caseExpr.eval(ctx, false)
+		selectedValue, err = caseData.caseExpr.Eval(ctx)
 		match = true
 	} else if filterList, ok := caseData.filterList.value().([]*term); ok {
 		if len(filterList) == 0 && exprValue == int64(caseIndex) {
-			selectedValue, err = caseData.caseExpr.eval(ctx, false)
+			selectedValue, err = caseData.caseExpr.Eval(ctx)
 			match = true
 		} else {
 			var caseValue any
 			for _, caseTerm := range filterList {
 				if caseValue, err = caseTerm.compute(ctx); err != nil || caseValue == exprValue {
-					selectedValue, err = caseData.caseExpr.eval(ctx, false)
+					selectedValue, err = caseData.caseExpr.Eval(ctx)
 					match = true
 					break
 				}

simple-store.go

@@ -11,6 +11,7 @@ import (
 )
 
 type SimpleStore struct {
+	parent    ExprContext
 	varStore  map[string]any
 	funcStore map[string]ExprFunc
 }
@@ -26,6 +27,14 @@ func NewSimpleStore() *SimpleStore {
 func filterRefName(name string) bool  { return name[0] != '@' }
 func filterPrivName(name string) bool { return name[0] != '_' }
 
+func (ctx *SimpleStore) SetParent(parentCtx ExprContext) {
+	ctx.parent = parentCtx
+}
+
+func (ctx *SimpleStore) GetParent() ExprContext {
+	return ctx.parent
+}
+
 func (ctx *SimpleStore) Clone() ExprContext {
 	return &SimpleStore{
 		varStore:  CloneFilteredMap(ctx.varStore, filterRefName),