org.mozilla.javascript.ast.VariableInitializer Maven / Gradle / Ivy
/* -*- Mode: java; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
package org.mozilla.javascript.ast;
import org.mozilla.javascript.Token;
/**
* A variable declaration or initializer, part of a {@link VariableDeclaration}
* expression. The variable "target" can be a simple name or a destructuring
* form. The initializer, if present, can be any expression.
*
* Node type is one of {@link Token#VAR}, {@link Token#CONST}, or
* {@link Token#LET}.
*/
public class VariableInitializer extends AstNode {
private AstNode target;
private AstNode initializer;
{
type = Token.VAR;
}
/**
* Sets the node type.
* @throws IllegalArgumentException if {@code nodeType} is not one of
* {@link Token#VAR}, {@link Token#CONST}, or {@link Token#LET}
*/
public void setNodeType(int nodeType) {
if (nodeType != Token.VAR
&& nodeType != Token.CONST
&& nodeType != Token.LET)
throw new IllegalArgumentException("invalid node type");
setType(nodeType);
}
public VariableInitializer() {
}
public VariableInitializer(int pos) {
super(pos);
}
public VariableInitializer(int pos, int len) {
super(pos, len);
}
/**
* Returns true if this is a destructuring assignment. If so, the
* initializer must be non-{@code null}.
* @return {@code true} if the {@code target} field is a destructuring form
* (an {@link ArrayLiteral} or {@link ObjectLiteral} node)
*/
public boolean isDestructuring() {
return !(target instanceof Name);
}
/**
* Returns the variable name or destructuring form
*/
public AstNode getTarget() {
return target;
}
/**
* Sets the variable name or destructuring form, and sets
* its parent to this node.
* @throws IllegalArgumentException if target is {@code null}
*/
public void setTarget(AstNode target) {
// Don't throw exception if target is an "invalid" node type.
// See mozilla/js/tests/js1_7/block/regress-350279.js
if (target == null)
throw new IllegalArgumentException("invalid target arg");
this.target = target;
target.setParent(this);
}
/**
* Returns the initial value, or {@code null} if not provided
*/
public AstNode getInitializer() {
return initializer;
}
/**
* Sets the initial value expression, and sets its parent to this node.
* @param initializer the initial value. May be {@code null}.
*/
public void setInitializer(AstNode initializer) {
this.initializer = initializer;
if (initializer != null)
initializer.setParent(this);
}
@Override
public String toSource(int depth) {
StringBuilder sb = new StringBuilder();
sb.append(makeIndent(depth));
sb.append(target.toSource(0));
if (initializer != null) {
sb.append (" = ");
sb.append(initializer.toSource(0));
}
return sb.toString();
}
/**
* Visits this node, then the target expression, then the initializer
* expression if present.
*/
@Override
public void visit(NodeVisitor v) {
if (v.visit(this)) {
target.visit(v);
if (initializer != null) {
initializer.visit(v);
}
}
}
}