new operator dot '.' used to select an item or character from a list or a string respectively

operator-insert.go

@@ -4,7 +4,6 @@
 // operator-insert.go
 package expr
 
-
 //-------- insert term
 
 func newInsertTerm(tk *Token) (inst *term) {
@@ -12,7 +11,7 @@ func newInsertTerm(tk *Token) (inst *term) {
 		tk:       *tk,
 		children: make([]*term, 0, 2),
 		position: posInfix,
-		priority: priSign,
+		priority: priAssign,
 		evalFunc: evalInsert,
 	}
 }
@@ -22,7 +21,7 @@ func newAppendTerm(tk *Token) (inst *term) {
 		tk:       *tk,
 		children: make([]*term, 0, 2),
 		position: posInfix,
-		priority: priSign,
+		priority: priAssign,
 		evalFunc: evalAppend,
 	}
 }
@@ -38,7 +37,7 @@ func evalInsert(ctx ExprContext, self *term) (v any, err error) {
 		list, _ := rightValue.([]any)
 		v = append([]any{leftValue}, list...)
 	} else {
-		err = self.errIncompatibleType(rightValue)
+		err = self.errIncompatibleTypes(leftValue, rightValue)
 	}
 	return
 }
@@ -54,7 +53,7 @@ func evalAppend(ctx ExprContext, self *term) (v any, err error) {
 		list, _ := leftValue.([]any)
 		v = append(list, rightValue)
 	} else {
-		err = self.errIncompatibleType(leftValue)
+		err = self.errIncompatibleTypes(leftValue, rightValue)
 	}
 	return
 }