/*
* 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.openjena.riot.lang;
import static org.openjena.riot.tokens.TokenType.EOF ;
import static org.openjena.riot.tokens.TokenType.NODE ;
import org.openjena.atlas.AtlasException ;
import org.openjena.atlas.iterator.PeekIterator ;
import org.openjena.riot.ErrorHandler ;
import org.openjena.riot.RiotParseException ;
import org.openjena.riot.system.ParserProfile ;
import org.openjena.riot.tokens.Token ;
import org.openjena.riot.tokens.TokenType ;
import org.openjena.riot.tokens.Tokenizer ;
import com.hp.hpl.jena.graph.Node ;
/** Common operations for RIOT parsers - not the implementation LangRIOT */
public class LangEngine
{
protected ParserProfile profile ;
protected final Tokenizer tokens ;
private final PeekIterator<Token> peekIter ;
protected LangEngine(Tokenizer tokens, ParserProfile profile)
{
this.tokens = tokens ;
this.profile = profile ;
this.peekIter = new PeekIterator<Token>(tokens) ;
}
// ---- Managing tokens.
protected final Token peekToken()
{
// Avoid repeating.
if ( eof() ) return tokenEOF ;
return peekIter.peek() ;
}
// Set when we get to EOF to record line/col of the EOF.
private Token tokenEOF = null ;
protected final boolean eof()
{
if ( tokenEOF != null )
return true ;
if ( ! moreTokens() )
{
tokenEOF = new Token(tokens.getLine(), tokens.getColumn()) ;
tokenEOF.setType(EOF) ;
return true ;
}
return false ;
}
protected final boolean moreTokens()
{
return peekIter.hasNext() ;
}
protected final boolean lookingAt(TokenType tokenType)
{
if ( eof() )
return tokenType == EOF ;
if ( tokenType == NODE )
return peekToken().isNode() ;
// if ( tokenType == KEYWORD )
// {
// String image = tokenRaw().getImage() ;
// if ( image.equals(KW_TRUE) )
// return true ;
// if ( image.equals(KW_FALSE) )
// return true ;
// return false ;
// }
// NB IRIs and PREFIXED_NAMEs
return peekToken().hasType(tokenType) ;
}
// Remember line/col of last token for messages
protected long currLine = -1 ;
protected long currCol = -1 ;
protected final Token nextToken()
{
if ( eof() )
return tokenEOF ;
// Tokenizer errors appear here!
try {
Token t = peekIter.next() ;
currLine = t.getLine() ;
currCol = t.getColumn() ;
return t ;
} catch (RiotParseException ex)
{
// Intercept to log it.
raiseException(ex) ;
throw ex ;
}
catch (AtlasException ex)
{
// Bad I/O
RiotParseException ex2 = new RiotParseException(ex.getMessage(), -1, -1) ;
raiseException(ex2) ;
throw ex2 ;
}
}
protected final Node scopedBNode(Node scopeNode, String label)
{
return profile.getLabelToNode().get(scopeNode, label) ;
}
protected final void expectOrEOF(String msg, TokenType tokenType)
{
// DOT or EOF
if ( eof() )
return ;
expect(msg, tokenType) ;
}
protected final void expect(String msg, TokenType ttype)
{
if ( ! lookingAt(ttype) )
{
Token location = peekToken() ;
exception(location, msg) ;
}
nextToken() ;
}
protected final void exception(Token token, String msg, Object... args)
{
if ( token != null )
exceptionDirect(String.format(msg, args), token.getLine(), token.getColumn()) ;
else
exceptionDirect(String.format(msg, args), -1, -1) ;
}
protected final void exceptionDirect(String msg, long line, long col)
{
raiseException(new RiotParseException(msg, line, col)) ;
}
protected final void raiseException(RiotParseException ex)
{
ErrorHandler errorHandler = profile.getHandler() ;
if ( errorHandler != null )
errorHandler.fatal(ex.getOriginalMessage(), ex.getLine(), ex.getCol()) ;
throw ex ;
}
}