All Downloads are FREE. Search and download functionalities are using the official Maven repository.

io.debezium.antlr.CaseChangingCharStream Maven / Gradle / Ivy

There is a newer version: 3.0.2.Final
Show newest version
/*
 * Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
 *
 * Licensed under the BSD 3-clause license, available at https://raw.githubusercontent.com/antlr/antlr4/master/LICENSE.txt
 */

package io.debezium.antlr;

import org.antlr.v4.runtime.CharStream;
import org.antlr.v4.runtime.misc.Interval;

/**
 * https://github.com/parrt/antlr4/blob/case-insensitivity-doc/doc/resources/CaseChangingCharStream.java
 * 

* This class supports case-insensitive lexing by wrapping an existing * {@link CharStream} and forcing the lexer to see either upper or * lowercase characters. Grammar literals should then be either upper or * lower case such as 'BEGIN' or 'begin'. The text of the character * stream is unaffected. Example: input 'BeGiN' would match lexer rule * 'BEGIN' if constructor parameter upper=true but getText() would return * 'BeGiN'. */ public class CaseChangingCharStream implements CharStream { final CharStream stream; final boolean upper; /** * Constructs a new CaseChangingCharStream wrapping the given {@link CharStream} forcing * all characters to upper case or lower case. * * @param stream The stream to wrap. * @param upper If true force each symbol to upper case, otherwise force to lower. */ public CaseChangingCharStream(CharStream stream, boolean upper) { this.stream = stream; this.upper = upper; } @Override public String getText(Interval interval) { return stream.getText(interval); } @Override public void consume() { stream.consume(); } @Override public int LA(int i) { int c = stream.LA(i); if (c <= 0) { return c; } if (upper) { return Character.toUpperCase(c); } return Character.toLowerCase(c); } @Override public int mark() { return stream.mark(); } @Override public void release(int marker) { stream.release(marker); } @Override public int index() { return stream.index(); } @Override public void seek(int index) { stream.seek(index); } @Override public int size() { return stream.size(); } @Override public String getSourceName() { return stream.getSourceName(); } }





© 2015 - 2024 Weber Informatics LLC | Privacy Policy