new string operator '/'

operator-prod.go

@@ -5,7 +5,6 @@
 package expr
 
 import (
-	"errors"
 	"strings"
 )
 
@@ -69,7 +68,7 @@ func divValues(opTerm *term, leftValue, rightValue any) (v any, err error) {
 		if IsFloat(leftValue) || IsFloat(rightValue) {
 			d := numAsFloat(rightValue)
 			if d == 0.0 {
-				err = errors.New("division by zero")
+				err = opTerm.errDivisionByZero()
 			} else {
 				v = numAsFloat(leftValue) / d
 			}
@@ -78,11 +77,36 @@ func divValues(opTerm *term, leftValue, rightValue any) (v any, err error) {
 		} else {
 			leftInt, _ := leftValue.(int64)
 			if rightInt, _ := rightValue.(int64); rightInt == 0 {
-				err = errors.New("division by zero")
+				err = opTerm.errDivisionByZero()
 			} else {
 				v = leftInt / rightInt
 			}
 		}
+	} else if IsString(leftValue) && IsString(rightValue) {
+		source := leftValue.(string)
+		sep := rightValue.(string)
+		v = ListFromStrings(strings.Split(source, sep))
+	} else if IsString(leftValue) && IsInteger(rightValue) {
+		source := leftValue.(string)
+		partSize := int(rightValue.(int64))
+		if partSize == 0 {
+			err = opTerm.errDivisionByZero()
+		} else {
+			partCount := len(source) / partSize
+			remainder := len(source) % partSize
+			listSize := partCount
+			if remainder > 0 {
+				listSize++
+			}
+			parts := make([]any, 0, listSize)
+			for i := 0; i < partCount; i++ {
+				parts = append(parts, source[i*partSize:(i+1)*partSize])
+			}
+			if remainder > 0 {
+				parts = append(parts, source[len(source)-remainder:])
+			}
+			v = newList(parts)
+		}
 	} else {
 		err = opTerm.errIncompatibleTypes(leftValue, rightValue)
 	}
@@ -121,7 +145,7 @@ func evalDivideAsFloat(ctx ExprContext, floatDivTerm *term) (v any, err error) {
 	if isNumOrFract(leftValue) && isNumOrFract(rightValue) {
 		d := numAsFloat(rightValue)
 		if d == 0.0 {
-			err = errors.New("division by zero")
+			err = floatDivTerm.errDivisionByZero()
 		} else {
 			v = numAsFloat(leftValue) / d
 		}
@@ -146,7 +170,7 @@ func remainderValues(opTerm *term, leftValue, rightValue any) (v any, err error)
 	if IsInteger(leftValue) && IsInteger(rightValue) {
 		rightInt, _ := rightValue.(int64)
 		if rightInt == 0 {
-			err = errors.New("division by zero")
+			err = opTerm.errDivisionByZero()
 		} else {
 			leftInt, _ := leftValue.(int64)
 			v = leftInt % rightInt