ASTPrinter.java

/*
 * ASTPrinter.java
 * 
 * Copyright (c) 2006 David Holroyd
 *
 * Licensed under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package uk.co.badgersinfoil.metaas.impl;

import java.io.PrintWriter;
import java.io.Writer;
import uk.co.badgersinfoil.metaas.impl.antlr.LinkedListToken;
import uk.co.badgersinfoil.metaas.impl.antlr.LinkedListTree;


public class ASTPrinter {
	
	PrintWriter out;

	public ASTPrinter(Writer out) {
		this.out = new PrintWriter(out);
	}

	public void print(LinkedListTree ast) {
		for (LinkedListToken tok=findStart(ast); tok!=null; tok=tok.getNext()) {
			print(tok);
		}
	}

	private LinkedListToken findStart(LinkedListTree ast) {
		LinkedListToken result = null;
		for (LinkedListToken tok=ast.getStartToken(); viable(tok); tok=tok.getPrev()) {
			result = tok;
		}
		return result;
	}

	private boolean viable(LinkedListToken tok) {
		return tok != null && tok.getType() != LinkedListToken.EOF;
	}

	private void print(LinkedListToken tok) {
		if (tok.getText() != null) {
			out.write(tok.getText());
		}
	}
}