/* $Id$ */
/**
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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 org.apache.manifoldcf.scriptengine;
/** While command. */
public class WhileCommand implements Command
{
/** Parse and execute. Parsing begins right after the command name, and should stop before the trailing semicolon.
*@param sp is the script parser to use to help in the parsing.
*@param currentStream is the current token stream.
*@return true to send a break signal, false otherwise.
*/
public boolean parseAndExecute(ScriptParser sp, TokenStream currentStream)
throws ScriptException
{
RewindableTokenStream rts = new RewindableTokenStream(currentStream);
boolean breakFromLoop = false;
while (true)
{
rts.reset();
if (breakFromLoop)
{
sp.skipStatements(rts);
break;
}
VariableReference whileCondition = sp.evaluateExpression(rts);
if (whileCondition == null)
sp.syntaxError(rts,"Missing while expression");
Token t = rts.peek();
if (t == null || t.getToken() == null || !t.getToken().equals("do"))
sp.syntaxError(rts,"Missing 'do' in while statement");
rts.skip();
if (sp.resolveMustExist(rts,whileCondition).getBooleanValue())
{
breakFromLoop = sp.parseStatements(rts);
}
else
{
sp.skipStatements(rts);
break;
}
}
return false;
}
/** Parse and skip. Parsing begins right after the command name, and should stop before the trailing semicolon.
*@param sp is the script parser to use to help in the parsing.
*@param currentStream is the current token stream.
*/
public void parseAndSkip(ScriptParser sp, TokenStream currentStream)
throws ScriptException
{
if (sp.skipExpression(currentStream) == false)
sp.syntaxError(currentStream,"Missing while expression");
Token t = currentStream.peek();
if (t == null || t.getToken() == null || !t.getToken().equals("do"))
sp.syntaxError(currentStream,"Missing 'do' in if statement");
currentStream.skip();
sp.skipStatements(currentStream);
}
}