/**
 *
 * Copyright (c) 1996-1997 Sun Microsystems, Inc.
 *
 * Use of this file and the system it is part of is constrained by the
 * file COPYRIGHT in the root directory of this system.
 *
 */

/* This is an example of how the Visitor pattern might be used to
   implement the dumping code that comes with SimpleNode.  It's a bit
   long-winded, but it does illustrate a couple of the main points.

   1) the visitor can maintain state between the nodes that it visits
   (for example the current indentation level).

   2) if you don't implement a jjtAccept() method for a subclass of
   SimpleNode, then SimpleNode's acceptor will get called.

   3) the utility method childrenAccept() can be useful when
   implementing preorder or postorder tree walks.

   Err, that's it. */

package weasel.jep;


public class ParserDumpVisitor implements ParserVisitor {
	private int indent = 0;

	private String indentString() {
		StringBuffer sb = new StringBuffer();
		for (int i = 0; i < indent; ++i) {
			sb.append("  ");
		}
		return sb.toString();
	}

	@Override
	public Object visit(SimpleNode node, Object data) throws ParseException {
		System.out.println(indentString() + node + ": acceptor not unimplemented in subclass?");
		++indent;
		data = node.childrenAccept(this, data);
		--indent;
		return data;
	}

	@Override
	public Object visit(ASTStart node, Object data) throws ParseException {
		System.out.println(indentString() + node);
		++indent;
		data = node.childrenAccept(this, data);
		--indent;
		return data;
	}

	@Override
	public Object visit(ASTFunNode node, Object data) throws ParseException {
		System.out.println(indentString() + node);
		++indent;
		data = node.childrenAccept(this, data);
		--indent;
		return data;
	}

	@Override
	public Object visit(ASTVarNode node, Object data) throws ParseException {
		System.out.println(indentString() + node);
		++indent;
		data = node.childrenAccept(this, data);
		--indent;
		return data;
	}

	@Override
	public Object visit(ASTConstant node, Object data) throws ParseException {
		System.out.println(indentString() + node);
		++indent;
		data = node.childrenAccept(this, data);
		--indent;
		return data;
	}
}

/*end*/
