Branch_c.java

/*
 *  This file is part of the X10 project (http://x10-lang.org).
 *
 *  This file is licensed to You under the Eclipse Public License (EPL);
 *  You may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *      http://www.opensource.org/licenses/eclipse-1.0.php
 *
 * This file was originally derived from the Polyglot extensible compiler framework.
 *
 *  (C) Copyright 2000-2007 Polyglot project group, Cornell University
 *  (C) Copyright IBM Corporation 2007-2012.
 */

package polyglot.ast;

import java.util.Collections;
import java.util.List;

import polyglot.util.CodeWriter;
import polyglot.util.Position;
import polyglot.visit.*;

/**
 * A <code>Branch</code> is an immutable representation of a branch
 * statment in Java (a break or continue).
 */
public class Branch_c extends Stmt_c implements Branch
{
    protected Branch.Kind kind;
    protected Id label;

    public Branch_c(Position pos, Branch.Kind kind, Id label) {
	super(pos);
	assert(kind != null); // label may be null
	this.kind = kind;
	this.label = label;
    }

    /** Get the kind of the branch. */
    public Branch.Kind kind() {
	return this.kind;
    }

    /** Set the kind of the branch. */
    public Branch kind(Branch.Kind kind) {
	Branch_c n = (Branch_c) copy();
	n.kind = kind;
	return n;
    }
    
    /** Get the target label of the branch. */
    public Id labelNode() {
        return this.label;
    }
    
    /** Set the target label of the branch. */
    public Branch labelNode(Id label) {
        Branch_c n = (Branch_c) copy();
        n.label = label;
        return n;
    }

    /** Reconstruct the expression. */
    protected Branch_c reconstruct(Id label) {
        if (label != this.label) {
            Branch_c n = (Branch_c) copy();
            n.label = label;
            return n;
        }
        
        return this;
    }
    
    /** Visit the children of the constructor. */
    public Node visitChildren(NodeVisitor v) {
        Id label = (Id) visitChild(this.label, v);
        return reconstruct(label);
    }

    public String toString() {
	return kind.toString() + (label != null ? " " + label.toString() : "");
    }

    /** Write the expression to an output file. */
    public void prettyPrint(CodeWriter w, PrettyPrinter tr) {
	w.write(kind.toString());
	if (label != null) {
	    w.write(" " + label);
	}
	w.write(";");
    }

    /**
     * Return the first (sub)term performed when evaluating this
     * term.
     */
    public Term firstChild() {
        return null;
    }

    public <S> List<S> acceptCFG(CFGBuilder v, List<S> succs) {
        v.visitBranchTarget(this);
        return Collections.<S>emptyList();
    }
}