org.antlr.v4.runtime.CommonTokenFactory Maven / Gradle / Ivy
/*
* Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
* Use of this file is governed by the BSD 3-clause license that
* can be found in the LICENSE.txt file in the project root.
*/
package org.antlr.v4.runtime;
import org.antlr.v4.runtime.misc.Interval;
import org.antlr.v4.runtime.misc.Pair;
/**
* This default implementation of {@link TokenFactory} creates
* {@link CommonToken} objects.
*/
public class CommonTokenFactory implements TokenFactory {
/**
* The default {@link CommonTokenFactory} instance.
*
*
* This token factory does not explicitly copy token text when constructing
* tokens.
*/
public static final TokenFactory DEFAULT = new CommonTokenFactory();
/**
* Indicates whether {@link CommonToken#setText} should be called after
* constructing tokens to explicitly set the text. This is useful for cases
* where the input stream might not be able to provide arbitrary substrings
* of text from the input after the lexer creates a token (e.g. the
* implementation of {@link CharStream#getText} in
* {@link UnbufferedCharStream} throws an
* {@link UnsupportedOperationException}). Explicitly setting the token text
* allows {@link Token#getText} to be called at any time regardless of the
* input stream implementation.
*
*
* The default value is {@code false} to avoid the performance and memory
* overhead of copying text for every token unless explicitly requested.
*/
protected final boolean copyText;
/**
* Constructs a {@link CommonTokenFactory} with the specified value for
* {@link #copyText}.
*
*
* When {@code copyText} is {@code false}, the {@link #DEFAULT} instance
* should be used instead of constructing a new instance.
*
* @param copyText The value for {@link #copyText}.
*/
public CommonTokenFactory(boolean copyText) { this.copyText = copyText; }
/**
* Constructs a {@link CommonTokenFactory} with {@link #copyText} set to
* {@code false}.
*
*
* The {@link #DEFAULT} instance should be used instead of calling this
* directly.
*/
public CommonTokenFactory() { this(false); }
@Override
public CommonToken create(Pair source, int type, String text,
int channel, int start, int stop,
int line, int charPositionInLine)
{
CommonToken t = new CommonToken(source, type, channel, start, stop);
t.setLine(line);
t.setCharPositionInLine(charPositionInLine);
if ( text!=null ) {
t.setText(text);
}
else if ( copyText && source.b != null ) {
t.setText(source.b.getText(Interval.of(start,stop)));
}
return t;
}
@Override
public CommonToken create(int type, String text) {
return new CommonToken(type, text);
}
}