/* -*- Mode: java; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
*
* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is Rhino code, released
* May 6, 1999.
*
* The Initial Developer of the Original Code is
* Netscape Communications Corporation.
* Portions created by the Initial Developer are Copyright (C) 1997-1999
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* Steve Yegge
*
* Alternatively, the contents of this file may be used under the terms of
* the GNU General Public License Version 2 or later (the "GPL"), in which
* case the provisions of the GPL are applicable instead of those above. If
* you wish to allow use of your version of this file only under the terms of
* the GPL and not to allow others to use your version of this file under the
* MPL, indicate your decision by deleting the provisions above and replacing
* them with the notice and other provisions required by the GPL. If you do
* not delete the provisions above, a recipient may use your version of this
* file under either the MPL or the GPL.
*
* ***** END LICENSE BLOCK ***** */
package org.mozilla.javascript.ast;
import org.mozilla.javascript.Token;
/**
* AST node for a simple name. A simple name is an identifier that is
* not a keyword. Node type is {@link Token#NAME}.<p>
*
* This node type is also used to represent certain non-identifier names that
* are part of the language syntax. It's used for the "get" and "set"
* pseudo-keywords for object-initializer getter/setter properties, and it's
* also used for the "*" wildcard in E4X XML namespace and name expressions.
*/
public class Name extends AstNode {
private String identifier;
private Scope scope;
{
type = Token.NAME;
}
public Name() {
}
public Name(int pos) {
super(pos);
}
public Name(int pos, int len) {
super(pos, len);
}
/**
* Constructs a new {@link Name}
* @param pos node start position
* @param len node length
* @param name the identifier associated with this {@code Name} node
*/
public Name(int pos, int len, String name) {
super(pos, len);
setIdentifier(name);
}
public Name(int pos, String name) {
super(pos);
setIdentifier(name);
setLength(name.length());
}
/**
* Returns the node's identifier
*/
public String getIdentifier() {
return identifier;
}
/**
* Sets the node's identifier
* @throws IllegalArgumentException if identifier is null
*/
public void setIdentifier(String identifier) {
assertNotNull(identifier);
this.identifier = identifier;
setLength(identifier.length());
}
/**
* Set the {@link Scope} associated with this node. This method does not
* set the scope's ast-node field to this node. The field exists only
* for temporary storage by the code generator. Not every name has an
* associated scope - typically only function and variable names (but not
* property names) are registered in a scope.
*
* @param s the scope. Can be null. Doesn't set any fields in the
* scope.
*/
public void setScope(Scope s) {
scope = s;
}
/**
* Return the {@link Scope} associated with this node. This is
* <em>only</em> used for (and set by) the code generator, so it will always
* be null in frontend AST-processing code. Use {@link #getDefiningScope}
* to find the lexical {@code Scope} in which this {@code Name} is defined,
* if any.
*/
public Scope getScope() {
return scope;
}
/**
* Returns the {@link Scope} in which this {@code Name} is defined.
* @return the scope in which this name is defined, or {@code null}
* if it's not defined in the current lexical scope chain
*/
public Scope getDefiningScope() {
Scope enclosing = getEnclosingScope();
String name = getIdentifier();
return enclosing == null ? null : enclosing.getDefiningScope(name);
}
/**
* Return true if this node is known to be defined as a symbol in a
* lexical scope other than the top-level (global) scope.
*
* @return {@code true} if this name appears as local variable, a let-bound
* variable not in the global scope, a function parameter, a loop
* variable, the property named in a {@link PropertyGet}, or in any other
* context where the node is known not to resolve to the global scope.
* Returns {@code false} if the node is defined in the top-level scope
* (i.e., its defining scope is an {@link AstRoot} object), or if its
* name is not defined as a symbol in the symbol table, in which case it
* may be an external or built-in name (or just an error of some sort.)
*/
public boolean isLocalName() {
Scope scope = getDefiningScope();
return scope != null && scope.getParentScope() != null;
}
/**
* Return the length of this node's identifier, to let you pretend
* it's a {@link String}. Don't confuse this method with the
* {@link AstNode#getLength} method, which returns the range of
* characters that this node overlaps in the source input.
*/
public int length() {
return identifier == null ? 0 : identifier.length();
}
@Override
public String toSource(int depth) {
return makeIndent(depth) + (identifier == null ? "<null>" : identifier);
}
/**
* Visits this node. There are no children to visit.
*/
@Override
public void visit(NodeVisitor v) {
v.visit(this);
}
}