/*******************************************************************************
* LastCalc - The last calculator you'll ever need
* Copyright (C) 2011, 2012 Uprizer Labs LLC
*
* This program is free software: you can redistribute it and/or modify it
* under the terms of the GNU Affero General Public License as published
* by the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR
* PURPOSE. See the GNU Affero General Public License for more
* details.
******************************************************************************/
package com.lastcalc.parsers.collections;
import java.util.List;
import com.google.common.collect.Lists;
import com.lastcalc.TokenList;
import com.lastcalc.parsers.*;
import com.lastcalc.parsers.UserDefinedParserParser.UserDefinedParser;
public class Filter extends Parser {
private static final long serialVersionUID = 9178891850811247754L;
private static TokenList template = TokenList.createD("filter", Lists.newArrayList(List.class), "with",
UserDefinedParser.class);
@Override
public ParseResult parse(final TokenList tokens, final int templatePos, final ParserContext context) {
final UserDefinedParser udp = (UserDefinedParser) tokens.get(templatePos + 3);
final Object datastructure = tokens.get(templatePos + 1);
List<Object> ret;
if (datastructure instanceof List) {
if (udp.variables.size() != 1 || udp.getTemplate().size() != 1)
return ParseResult.fail();
final List<Object> list = (List<Object>) datastructure;
ret = Lists.newArrayListWithCapacity(list.size() * 4);
ret.add("[");
for (final Object o : list) {
final TokenList result = context.parseEngine.parseAndGetLastStep(
udp.parse(TokenList.createD(o), 0).output, context);
if (result.size() != 1 || !(result.get(0) instanceof Boolean))
return ParseResult.fail();
if (result.get(0).equals(true)) {
ret.add(o);
ret.add(",");
}
}
ret.set(ret.size() - 1, "]"); // Overwrite last comma
} else
return ParseResult.fail();
return ParseResult.success(tokens.replaceWithTokenList(templatePos, templatePos + template.size(),
TokenList.create(ret)));
}
@Override
public TokenList getTemplate() {
return template;
}
@Override
public int hashCode() {
return "Filter".hashCode();
}
@Override
public boolean equals(final Object obj) {
return obj instanceof Filter;
}
}