org.apache.qpid.messaging.util.Parser Maven / Gradle / Ivy
/*
*
* 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.qpid.messaging.util;
import java.util.ArrayList;
import java.util.List;
/**
* Parser
*
*/
class Parser
{
private List tokens;
private int idx = 0;
Parser(List tokens)
{
this.tokens = tokens;
this.idx = 0;
}
Token next()
{
return tokens.get(idx);
}
boolean matches(Token.Type ... types)
{
for (Token.Type t : types)
{
if (next().getType() == t)
{
return true;
}
}
return false;
}
Token eat(Token.Type ... types)
{
if (types.length > 0 && !matches(types))
{
throw new ParseError(next(), types);
}
else
{
Token t = next();
idx += 1;
return t;
}
}
List eat_until(Token.Type ... types)
{
List result = new ArrayList();
while (!matches(types))
{
result.add(eat());
}
return result;
}
/**
* Returns the remaining list of tokens, without eating them
*/
List remainder()
{
List result = new ArrayList();
for (int i = idx; i < tokens.size(); i++)
{
result.add(tokens.get(i));
}
return result;
}
}