Some data-type check functions (e.g. IsInteger()) exported

doc/Expr.adoc

@@ -22,15 +22,92 @@ Expressions calculator
 
 toc::[]
 
-#TODO: Work in progress#
+#TODO: Work in progress (last update on 2024/05/07, 07:15 am)#
 
 == Expr
 _Expr_ is a GO package capable of analysing, interpreting and calculating expressions.
 
+=== `dev-expr` test tool
+`dev-expr` is a simple program that can be used to evaluate expressions interactively. As its name suggests, it was created for testing purpose. In fact, beyond in additon to the automatic test suite based on the Go test framework, `dev-expr` provides an important aid for quickly testing of new features during their development.
+
+It cat work as a REPL, *R*ead-*E*xecute-*P*rint-*L*oop, or it can process expression acquired from files or standard input.
+
+The program in located in the _tools_ directory.
+Here are some examples of execution.
+
+.Run `dev-expr` in REPL mode and ask for help
+[source,shell]
+----
+# Assume the expr source directory. Type 'exit' or Ctrl+D to quit the program.
+
+[user]$ tools/expr -- Expressions calculator v1.7.0,2024/05/08 (celestino.amoroso@portale-stac.it)
+	Type help to get the list of command.
+	See also https://git.portale-stac.it/go-pkg/expr/src/branch/main/README.adoc
+
+>>> help
+--- REPL commands:
+        base -- Set the integer output base: 2, 8, 10, or 16
+        exit -- Exit the program
+        help -- Show command list
+          ml -- Enable/Disable multi-line output
+        mods -- List builtin modules
+      source -- Load a file as input
+         tty -- Enable/Disable ansi output <1>
+
+--- Command line options:
+    -b <builtin>       Import builtin modules.
+                       <builtin> can be a list of module names or a glob-pattern.
+                       Use the special value 'all' or the pattern '*' to import all modules.
+    -e <expression>    Evaluate <expression> instead of standard-input
+    -i                 Force REPL operation when all -e occurences have been processed
+    -h, --help, help   Show this help menu
+    -m, --modules      List all builtin modules
+    -p                 Print prefix form
+    -t                 Print tree form <2>
+
+>>> 
+----
+
+<1> Only available for single fraction values
+<2> Work in progress
+
+.REPL examples
+[source,shell]
+----
+[user]$ tools/expr -- Expressions calculator v1.6.1,2024/05/06 (celestino.amoroso@portale-stac.it)
+        Type help to get the list of command.
+        See also https://git.portale-stac.it/go-pkg/expr/src/branch/main/README.adoc
+>>> 2+3
+5
+>>> 2+3*(4-1.5)
+9.5
+>>> 0xFD + 0b1 + 0o1 <1>
+255
+>>> 1|2 + 2|3 <2>
+7|6
+>>> ml <3>
+>>> 1|2 + 2|3
+7
+-
+6
+>>> 1+2 but 5|2+0.5 <4>
+3
+>>> 1+2; 5|2+0.5 <5>
+3
+>>>
+----
+
+<1> Number bases: 0x = hexadecimal, 0o = octal, 0b = binary.
+<2> Fractions: numerator | denominator.
+<3> Activate multi-line output of fractions.
+<4> But operator, see <<_but_operator>>.
+<5> Multi-expression: the same result of the previous single expression but this it is obtained with two separated calculations.
 
 === Concepts and terminology
 #TODO#
 
+image::expression-diagram.png[]
+
 == Data types
 _Expr_ supports numerical, string, relational, boolean expressions, and mixed-type lists.
 
@@ -182,7 +259,7 @@ a=1; b=2; c=3; a+b+c    // returns 6
 ----
 
 === [blue]`but` operator
-[blue]`but` is an infixed operator. Its operands can be any type of expression. It evaluates the left expression first, then the right expression. The value of the right expression is the final result. Examples: [blue]`5 but 2` returns 2, [blue]`x=2*3 but x-1` returns 5.
+[blue]`but` is an infixed operator. Its operands can be expressions of any type. It evaluates the left expression first, then the right expression. The value of the right expression is the final result. Examples: [blue]`5 but 2` returns 2, [blue]`x=2*3 but x-1` returns 5.
 
 [blue]`but` is very similar to [blue]`;`. The only difference is that [blue]`;` can't be used inside parenthesis [blue]`(` and [blue]`)`.
 

formatter.go

@@ -9,6 +9,10 @@ type FmtOpt uint16
 const (
 	TTY FmtOpt = 1 << iota
 	MultiLine
+	Base2
+	Base8
+	Base10
+	Base16
 )
 
 type Formatter interface {

func-import.go

@@ -35,7 +35,7 @@ func importGeneral(ctx ExprContext, name string, args []any) (result any, err er
 }
 
 func checkStringParamExpected(funcName string, paramValue any, paramPos int) (err error) {
-	if !(isString(paramValue) /*|| isList(paramValue)*/) {
+	if !(IsString(paramValue) /*|| isList(paramValue)*/) {
 		err = fmt.Errorf("%s(): param nr %d has wrong type %T, string expected", funcName, paramPos+1, paramValue)
 	}
 	return

func-math.go

@@ -10,7 +10,7 @@ import (
 )
 
 func checkNumberParamExpected(funcName string, paramValue any, paramPos, level, subPos int) (err error) {
-	if !(isNumber(paramValue) || isFraction(paramValue)) /*|| isList(paramValue)*/ {
+	if !(IsNumber(paramValue) || 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)
 	}
@@ -45,7 +45,7 @@ func doAdd(ctx ExprContext, name string, it Iterator, count, level int) (result
 		count++
 
 		if !sumAsFloat {
-			if isFloat(v) {
+			if IsFloat(v) {
 				sumAsFloat = true
 				if sumAsFract {
 					floatSum = fractSum.toFloat()
@@ -120,7 +120,7 @@ func doMul(ctx ExprContext, name string, it Iterator, count, level int) (result
 		count++
 
 		if !mulAsFloat {
-			if isFloat(v) {
+			if IsFloat(v) {
 				mulAsFloat = true
 				if mulAsFract {
 					floatProd = fractProd.toFloat()

operator-assign.go

@@ -1,5 +1,5 @@
 // Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
-// All rights reserved.
+// All rights reserightChilded.
 
 // operator-assign.go
 package expr
@@ -27,11 +27,17 @@ func evalAssign(ctx ExprContext, self *term) (v any, err error) {
 		return
 	}
 
-	if v, err = self.children[1].compute(ctx); err == nil {
-		if functor, ok := v.(Functor); ok {
-			var minArgs, maxArgs int = 0, 0
+	rightChild := self.children[1]
 
-			if funcDef, ok := functor.(*funcDefFunctor); ok {
+	if v, err = rightChild.compute(ctx); err == nil {
+		if functor, ok := v.(Functor); ok {
+			var minArgs, maxArgs int = 0, -1
+
+			funcName := rightChild.source()
+			if info, exists := ctx.GetFuncInfo(funcName); exists {
+				minArgs = info.MinArgs()
+				maxArgs = info.MaxArgs()
+			} else if funcDef, ok := functor.(*funcDefFunctor); ok {
 				l := len(funcDef.params)
 				minArgs = l
 				maxArgs = l

operator-builtin.go

@@ -26,7 +26,7 @@ func evalBuiltin(ctx ExprContext, self *term) (v any, err error) {
 	}
 
 	count := 0
-	if isString(childValue) {
+	if IsString(childValue) {
 		module, _ := childValue.(string)
 		count, err = ImportInContextByGlobPattern(ctx, module)
 	} else {

operator-fact.go

@@ -25,7 +25,7 @@ func evalFact(ctx ExprContext, self *term) (v any, err error) {
 		return
 	}
 
-	if isInteger(leftValue) {
+	if IsInteger(leftValue) {
 		if i, _ := leftValue.(int64); i >= 0 {
 			f := int64(1)
 			for k := int64(1); k <= i; k++ {

operator-include.go

@@ -24,7 +24,7 @@ func evalInclude(ctx ExprContext, self *term) (v any, err error) {
 	}
 
 	count := 0
-	if isList(childValue) {
+	if IsList(childValue) {
 		list, _ := childValue.([]any)
 		for i, filePathSpec := range list {
 			if filePath, ok := filePathSpec.(string); ok {
@@ -39,7 +39,7 @@ func evalInclude(ctx ExprContext, self *term) (v any, err error) {
 				break
 			}
 		}
-	} else if isString(childValue) {
+	} else if IsString(childValue) {
 		filePath, _ := childValue.(string)
 		v, err = EvalFile(ctx, filePath)
 	} else {

operator-insert.go

@@ -33,7 +33,7 @@ func evalInsert(ctx ExprContext, self *term) (v any, err error) {
 		return
 	}
 
-	if isList(rightValue) {
+	if IsList(rightValue) {
 		list, _ := rightValue.(*ListType)
 		newList := append(ListType{leftValue}, *list...)
 		v = &newList
@@ -50,7 +50,7 @@ func evalAppend(ctx ExprContext, self *term) (v any, err error) {
 		return
 	}
 
-	if isList(leftValue) {
+	if IsList(leftValue) {
 		list, _ := leftValue.(*ListType)
 		newList := append(*list, rightValue)
 		v = &newList

operator-length.go

@@ -23,10 +23,10 @@ func evalLength(ctx ExprContext, self *term) (v any, err error) {
 		return
 	}
 
-	if isList(childValue) {
+	if IsList(childValue) {
 		list, _ := childValue.([]any)
 		v = int64(len(list))
-	} else if isString(childValue) {
+	} else if IsString(childValue) {
 		s, _ := childValue.(string)
 		v = int64(len(s))
 	} else if it, ok := childValue.(Iterator); ok {

operator-post-inc.go

@@ -25,7 +25,7 @@ func evalPostInc(ctx ExprContext, self *term) (v any, err error) {
 
 	if it, ok := childValue.(Iterator); ok {
 		v, err = it.Next()
-	} else if isInteger(childValue) && self.children[0].symbol() == SymIdentifier {
+	} else if IsInteger(childValue) && self.children[0].symbol() == SymIdentifier {
 		v = childValue
 		i, _ := childValue.(int64)
 		ctx.SetVar(self.children[0].source(), i+1)

operator-prod.go

@@ -30,20 +30,20 @@ func evalMultiply(ctx ExprContext, self *term) (v any, err error) {
 		return
 	}
 
-	if isString(leftValue) && isInteger(rightValue) {
+	if IsString(leftValue) && IsInteger(rightValue) {
 		s, _ := leftValue.(string)
 		n, _ := rightValue.(int64)
 		v = strings.Repeat(s, int(n))
-	} else if isNumber(leftValue) && isNumber(rightValue) {
-		if isFloat(leftValue) || isFloat(rightValue) {
+	} else if isNumOrFract(leftValue) && isNumOrFract(rightValue) {
+		if IsFloat(leftValue) || IsFloat(rightValue) {
 			v = numAsFloat(leftValue) * numAsFloat(rightValue)
+		} else if isFraction(leftValue) || isFraction(rightValue) {
+			v, err = mulAnyFract(leftValue, rightValue)
 		} else {
 			leftInt, _ := leftValue.(int64)
 			rightInt, _ := rightValue.(int64)
 			v = leftInt * rightInt
 		}
-	} else if isFraction(leftValue) || isFraction(rightValue) {
-		v, err = mulAnyFract(leftValue, rightValue)
 	} else {
 		err = self.errIncompatibleTypes(leftValue, rightValue)
 	}
@@ -71,14 +71,16 @@ func evalDivide(ctx ExprContext, self *term) (v any, err error) {
 		return
 	}
 
-	if isNumber(leftValue) && isNumber(rightValue) {
-		if isFloat(leftValue) || isFloat(rightValue) {
+	if isNumOrFract(leftValue) && isNumOrFract(rightValue) {
+		if IsFloat(leftValue) || IsFloat(rightValue) {
 			d := numAsFloat(rightValue)
 			if d == 0.0 {
 				err = errors.New("division by zero")
 			} else {
 				v = numAsFloat(leftValue) / d
 			}
+		} else if isFraction(leftValue) || isFraction(rightValue) {
+			v, err = divAnyFract(leftValue, rightValue)
 		} else {
 			leftInt, _ := leftValue.(int64)
 			if rightInt, _ := rightValue.(int64); rightInt == 0 {
@@ -87,8 +89,6 @@ func evalDivide(ctx ExprContext, self *term) (v any, err error) {
 				v = leftInt / rightInt
 			}
 		}
-	} else if isFraction(leftValue) || isFraction(rightValue) {
-		v, err = divAnyFract(leftValue, rightValue)
 	} else {
 		err = self.errIncompatibleTypes(leftValue, rightValue)
 	}
@@ -114,7 +114,7 @@ func evalDivideAsFloat(ctx ExprContext, self *term) (v any, err error) {
 		return
 	}
 
-	if isNumber(leftValue) && isNumber(rightValue) {
+	if isNumOrFract(leftValue) && isNumOrFract(rightValue) {
 		d := numAsFloat(rightValue)
 		if d == 0.0 {
 			err = errors.New("division by zero")
@@ -148,7 +148,7 @@ func evalReminder(ctx ExprContext, self *term) (v any, err error) {
 		return
 	}
 
-	if isInteger(leftValue) && isInteger(rightValue) {
+	if IsInteger(leftValue) && IsInteger(rightValue) {
 		rightInt, _ := rightValue.(int64)
 		if rightInt == 0 {
 			err = errors.New("division by zero")

operator-rel.go

@@ -25,15 +25,15 @@ func evalEqual(ctx ExprContext, self *term) (v any, err error) {
 		return
 	}
 
-	if isNumber(leftValue) && isNumber(rightValue) {
-		if isInteger(leftValue) && isInteger(rightValue) {
+	if IsNumber(leftValue) && IsNumber(rightValue) {
+		if IsInteger(leftValue) && IsInteger(rightValue) {
 			li, _ := leftValue.(int64)
 			ri, _ := rightValue.(int64)
 			v = li == ri
 		} else {
 			v = numAsFloat(leftValue) == numAsFloat(rightValue)
 		}
-	} else if isString(leftValue) && isString(rightValue) {
+	} else if IsString(leftValue) && IsString(rightValue) {
 		ls, _ := leftValue.(string)
 		rs, _ := rightValue.(string)
 		v = ls == rs
@@ -111,15 +111,15 @@ func evalLess(ctx ExprContext, self *term) (v any, err error) {
 		return
 	}
 
-	if isNumber(leftValue) && isNumber(rightValue) {
-		if isInteger(leftValue) && isInteger(rightValue) {
+	if IsNumber(leftValue) && IsNumber(rightValue) {
+		if IsInteger(leftValue) && IsInteger(rightValue) {
 			li, _ := leftValue.(int64)
 			ri, _ := rightValue.(int64)
 			v = li < ri
 		} else {
 			v = numAsFloat(leftValue) < numAsFloat(rightValue)
 		}
-	} else if isString(leftValue) && isString(rightValue) {
+	} else if IsString(leftValue) && IsString(rightValue) {
 		ls, _ := leftValue.(string)
 		rs, _ := rightValue.(string)
 		v = ls < rs
@@ -148,15 +148,15 @@ func evalLessEqual(ctx ExprContext, self *term) (v any, err error) {
 		return
 	}
 
-	if isNumber(leftValue) && isNumber(rightValue) {
-		if isInteger(leftValue) && isInteger(rightValue) {
+	if IsNumber(leftValue) && IsNumber(rightValue) {
+		if IsInteger(leftValue) && IsInteger(rightValue) {
 			li, _ := leftValue.(int64)
 			ri, _ := rightValue.(int64)
 			v = li <= ri
 		} else {
 			v = numAsFloat(leftValue) <= numAsFloat(rightValue)
 		}
-	} else if isString(leftValue) && isString(rightValue) {
+	} else if IsString(leftValue) && IsString(rightValue) {
 		ls, _ := leftValue.(string)
 		rs, _ := rightValue.(string)
 		v = ls <= rs

operator-sign.go

@@ -35,14 +35,14 @@ func evalSign(ctx ExprContext, self *term) (v any, err error) {
 		return
 	}
 
-	if isFloat(rightValue) {
+	if IsFloat(rightValue) {
 		if self.tk.Sym == SymChangeSign {
 			f, _ := rightValue.(float64)
 			v = -f
 		} else {
 			v = rightValue
 		}
-	} else if isInteger(rightValue) {
+	} else if IsInteger(rightValue) {
 		if self.tk.Sym == SymChangeSign {
 			i, _ := rightValue.(int64)
 			v = -i

operator-sum.go

@@ -28,17 +28,17 @@ func evalPlus(ctx ExprContext, self *term) (v any, err error) {
 		return
 	}
 
-	if (isString(leftValue) && isNumberString(rightValue)) || (isString(rightValue) && isNumberString(leftValue)) {
+	if (IsString(leftValue) && isNumberString(rightValue)) || (IsString(rightValue) && isNumberString(leftValue)) {
 		v = fmt.Sprintf("%v%v", leftValue, rightValue)
-	} else if isNumber(leftValue) && isNumber(rightValue) {
-		if isFloat(leftValue) || isFloat(rightValue) {
+	} else if IsNumber(leftValue) && IsNumber(rightValue) {
+		if IsFloat(leftValue) || IsFloat(rightValue) {
 			v = numAsFloat(leftValue) + numAsFloat(rightValue)
 		} else {
 			leftInt, _ := leftValue.(int64)
 			rightInt, _ := rightValue.(int64)
 			v = leftInt + rightInt
 		}
-	} else if isList(leftValue) || isList(rightValue) {
+	} else if IsList(leftValue) || IsList(rightValue) {
 		var leftList, rightList *ListType
 		var ok bool
 		if leftList, ok = leftValue.(*ListType); !ok {
@@ -56,7 +56,11 @@ func evalPlus(ctx ExprContext, self *term) (v any, err error) {
 		}
 		v = &sumList
 	} else if isFraction(leftValue) || isFraction(rightValue) {
-		v, err = sumAnyFract(leftValue, rightValue)
+		if IsFloat(leftValue) || IsFloat(rightValue) {
+			v = numAsFloat(leftValue) + numAsFloat(rightValue)
+		} else {
+			v, err = sumAnyFract(leftValue, rightValue)
+		}
 	} else {
 		err = self.errIncompatibleTypes(leftValue, rightValue)
 	}
@@ -82,15 +86,17 @@ func evalMinus(ctx ExprContext, self *term) (v any, err error) {
 		return
 	}
 
-	if isNumber(leftValue) && isNumber(rightValue) {
-		if isFloat(leftValue) || isFloat(rightValue) {
+	if isNumOrFract(leftValue) && isNumOrFract(rightValue) {
+		if IsFloat(leftValue) || IsFloat(rightValue) {
 			v = numAsFloat(leftValue) - numAsFloat(rightValue)
+		} else if isFraction(leftValue) || isFraction(rightValue) {
+			v, err = subAnyFract(leftValue, rightValue)
 		} else {
 			leftInt, _ := leftValue.(int64)
 			rightInt, _ := rightValue.(int64)
 			v = leftInt - rightInt
 		}
-	} else if isList(leftValue) && isList(rightValue) {
+	} else if IsList(leftValue) && IsList(rightValue) {
 		leftList, _ := leftValue.(*ListType)
 		rightList, _ := rightValue.(*ListType)
 		diffList := make(ListType, 0, len(*leftList)-len(*rightList))
@@ -100,8 +106,6 @@ func evalMinus(ctx ExprContext, self *term) (v any, err error) {
 			}
 		}
 		v = &diffList
-	} else if isFraction(leftValue) || isFraction(rightValue) {
-		v, err = subAnyFract(leftValue, rightValue)
 	} else {
 		err = self.errIncompatibleTypes(leftValue, rightValue)
 	}

parser_test.go

@@ -157,6 +157,7 @@ func TestGeneralParser(t *testing.T) {
 		/* 136 */ {`builtin "math.arith"; mul(1|2, 1.0, 2)`, float64(1.0), nil},
 		/* 137 */ {`builtin "os.file"`, int64(1), nil},
 		/* 138 */ {`v=10; v++; v`, int64(11), nil},
+		/* 139 */ {`1+1|2+0.5`, float64(2), nil},
 	}
 
 	// t.Setenv("EXPR_PATH", ".")

utils.go

@@ -9,37 +9,41 @@ import (
 	"reflect"
 )
 
-func isString(v any) (ok bool) {
+func IsString(v any) (ok bool) {
 	_, ok = v.(string)
 	return ok
 }
 
-func isInteger(v any) (ok bool) {
+func IsInteger(v any) (ok bool) {
 	_, ok = v.(int64)
 	return ok
 }
 
-func isFloat(v any) (ok bool) {
+func IsFloat(v any) (ok bool) {
 	_, ok = v.(float64)
 	return ok
 }
 
-func isList(v any) (ok bool) {
+func IsList(v any) (ok bool) {
 	_, ok = v.(*ListType)
 	return ok
 }
 
-func isDict(v any) (ok bool) {
+func IsDict(v any) (ok bool) {
 	_, ok = v.(map[any]any)
 	return ok
 }
 
-func isNumber(v any) (ok bool) {
-	return isFloat(v) || isInteger(v)
+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)
+	return IsString(v) || IsNumber(v)
 }
 
 func isFunctor(v any) (ok bool) {