Added all source files

operator-prod.go

@@ -0,0 +1,95 @@
+// operator-prod.go
+package expr
+
+import (
+	"errors"
+	"strings"
+)
+
+//-------- multiply term
+
+func newMultiplyTerm(tk *Token) (inst *term) {
+	return &term{
+		tk:       *tk,
+		class:    classOperator,
+		kind:     kindUnknown,
+		children: make([]*term, 0, 2),
+		position: posInfix,
+		priority: priProduct,
+		evalFunc: evalMultiply,
+	}
+}
+
+func evalMultiply(ctx exprContext, self *term) (v any, err error) {
+	var leftValue, rightValue any
+
+	if leftValue, rightValue, err = self.evalInfix(ctx); err != nil {
+		return
+	}
+
+	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) {
+			v = numAsFloat(leftValue) * numAsFloat(rightValue)
+		} else {
+			leftInt, _ := leftValue.(int64)
+			rightInt, _ := rightValue.(int64)
+			v = leftInt * rightInt
+		}
+	} else {
+		err = self.errIncompatibleTypes(leftValue, rightValue)
+	}
+	return
+}
+
+//-------- divide term
+
+func newDivideTerm(tk *Token) (inst *term) {
+	return &term{
+		tk:       *tk,
+		class:    classOperator,
+		kind:     kindUnknown,
+		children: make([]*term, 0, 2),
+		position: posInfix,
+		priority: priProduct,
+		evalFunc: evalDivide,
+	}
+}
+
+func evalDivide(ctx exprContext, self *term) (v any, err error) {
+	var leftValue, rightValue any
+
+	if leftValue, rightValue, err = self.evalInfix(ctx); err != nil {
+		return
+	}
+
+	if isNumber(leftValue) && isNumber(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 {
+			leftInt, _ := leftValue.(int64)
+			if rightInt, _ := rightValue.(int64); rightInt == 0 {
+				err = errors.New("division by zero")
+			} else {
+				v = leftInt / rightInt
+			}
+		}
+	} else {
+		err = self.errIncompatibleTypes(leftValue, rightValue)
+	}
+	return
+}
+
+// init
+func init() {
+	registerTermConstructor(SymStar, newMultiplyTerm)
+	registerTermConstructor(SymSlash, newDivideTerm)
+}