/*
* $Id: WhileStatement.java,v 1.14 2002/09/16 08:05:06 jkl Exp $
*
* Copyright (c) 2002 Njet Communications Ltd. All Rights Reserved.
*
* Use is subject to license terms, as defined in
* Anvil Sofware License, Version 1.1. See LICENSE
* file, or http://njet.org/license-1.1.txt
*/
package anvil.script.statements;
import anvil.core.Any;
import anvil.Location;
import anvil.codec.Code;
import anvil.codec.Source;
import anvil.codec.Target;
import anvil.parser.Tag;
import anvil.ErrorListener;
import anvil.script.compiler.ByteCompiler;
import anvil.script.Context;
import anvil.script.expression.Expression;
import anvil.script.parser.TemplateParser;
import anvil.script.Grammar;
import java.io.IOException;
/**
* class WhileStatement
*
* @author: Jani Lehtim�ki
*/
public class WhileStatement extends ScopedStatement implements Labeled
{
private Expression _condition;
private Statement _statement = EMPTY;
private String _label;
private Source _startscope;
private Source _endscope;
public WhileStatement(Statement parent, Location location)
{
super(parent, location);
}
public WhileStatement(Statement parent, Location location, Expression condition, String label)
{
super(parent, location);
_condition = condition;
_label = label;
}
public int typeOf()
{
return Statement.ST_WHILE;
}
public String name()
{
return "while";
}
public String getLabel()
{
return _label;
}
public void parse(TemplateParser parser, Tag tag)
{
boolean negate = false;
String s = tag.getValue("expr");
if (s == null) {
s = tag.getValue("true");
if (s == null) {
s = tag.getValue("false");
if (s != null) {
negate = true;
}
}
}
_condition = Grammar.parseStandaloneExpression(s, getLocation(), parser);
if (negate) {
_condition.createNegation();
}
_label = parseLabel(parser, tag);
}
public boolean onTag(TemplateParser parser, int type, Tag tag)
{
switch(type) {
case ST_ENDWHILE:
parser.pop();
break;
default:
return super.onTag(parser, type, tag);
}
return true;
}
public Statement getChildStatement()
{
return _statement;
}
public void setChildStatement(Statement statement)
{
_statement = statement;
}
public void check(ErrorListener context)
{
_condition.check(context);
_statement.check(context);
}
public Jumps eliminate(ErrorListener context)
{
Jumps jumps = _statement.eliminate(context);
switch(_condition.conditionOf()) {
case Expression.IS_FALSE:
jumps = new Jumps();
break;
case Expression.IS_DYNAMIC:
jumps.setBlocked(false);
break;
case Expression.IS_TRUE:
jumps.setBlocked(!jumps.hasBreak());
break;
}
//jumps.print("while");
return jumps.shift();
}
public Source getStartOfScope()
{
return _startscope;
}
public Source getEndOfScope()
{
return _endscope;
}
public void compile(ByteCompiler context)
{
Code code = context.getCode();
Target start = code.getTarget();
switch(_condition.conditionOf()) {
case Expression.IS_FALSE:
return;
case Expression.IS_TRUE:
_startscope = code.getSource();
_endscope = code.getSource();
_statement.compile(context);
code.go_to(_startscope);
_startscope.bind(start);
_endscope.bind();
break;
case Expression.IS_DYNAMIC:
_startscope = code.getSource();
_endscope = code.getSource();
if (_condition.needLineNumbers()) {
context.location(_condition.getLocation());
}
_condition.compile(context, Expression.GET_BOOLEAN);
code.if_eq(_endscope);
_statement.compile(context);
if (!_statement.isBlocked()) {
code.go_to(_startscope);
}
_startscope.bind(start);
_endscope.bind();
break;
}
}
}