new operator 'in' added. It check if an item is member of a list, or if a key is contained in a dictionary

operand-list.go

@@ -6,6 +6,7 @@ package expr
 
 import (
 	"fmt"
+	"reflect"
 	"strings"
 )
 
@@ -61,6 +62,16 @@ func newList(listAny []any) (list *ListType) {
 	return
 }
 
+func (list *ListType) indexDeepCmp(target any) (index int) {
+	index = -1
+	for i, item := range *list {
+		if reflect.DeepEqual(item, target) {
+			index = i
+			break
+		}
+	}
+	return
+}
 
 // -------- list term
 func newListTermA(args ...*term) *term {