Fix visitor for arguments

Author: antonmedv

ast/visitor.go

@@ -64,18 +64,18 @@ func (w *walker) walk(node *Node) {
 		w.visitor.Exit(node)
 	case *MethodNode:
 		w.walk(&n.Node)
-		for _, arg := range n.Arguments {
-			w.walk(&arg)
+		for i := range n.Arguments {
+			w.walk(&n.Arguments[i])
 		}
 		w.visitor.Exit(node)
 	case *FunctionNode:
-		for _, arg := range n.Arguments {
-			w.walk(&arg)
+		for i := range n.Arguments {
+			w.walk(&n.Arguments[i])
 		}
 		w.visitor.Exit(node)
 	case *BuiltinNode:
-		for _, arg := range n.Arguments {
-			w.walk(&arg)
+		for i := range n.Arguments {
+			w.walk(&n.Arguments[i])
 		}
 		w.visitor.Exit(node)
 	case *ClosureNode:

cmd/exe/debugger.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"fmt"
+	"github.com/antonmedv/expr/checker"
 	"github.com/antonmedv/expr/compiler"
 	"github.com/antonmedv/expr/optimizer"
 	"github.com/antonmedv/expr/parser"
@@ -19,6 +20,9 @@ func debugger() {
 	tree, err := parser.Parse(input())
 	check(err)
 
+	_, err = checker.Check(tree, nil)
+	check(err)
+
 	if opt {
 		optimizer.Optimize(&tree.Node)
 	}

cmd/exe/main.go

@@ -80,15 +80,18 @@ func check(err error) {
 func printAst() {
 	tree, err := parser.Parse(input())
 	check(err)
-	if !dot {
-		litter.Dump(tree.Node)
-		return
-	}
+
+	_, err = checker.Check(tree, nil)
+	check(err)
 
 	if opt {
 		optimizer.Optimize(&tree.Node)
 	}
 
+	if !dot {
+		litter.Dump(tree.Node)
+		return
+	}
 	dotAst(tree.Node)
 }