ANTLR is a powerful parser generator for multiple programming languages including Java.

ANTLR contains 2 major modules:

• Runtime - For building and executing parsers/lexers generated in Java.
• Tool (The Parser Generator) - For generating parsers/lexers Java class.

ANTLR Runtime Source Code files are provided in the distribution packge (antlr4-4.10.1.zip). You can download them at ANTLR Website.

You can also browse the source code below:

⏎ org/antlr/v4/runtime/LexerInterpreter.java

/*
 * 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.atn.ATN;
import org.antlr.v4.runtime.atn.ATNType;
import org.antlr.v4.runtime.atn.LexerATNSimulator;
import org.antlr.v4.runtime.atn.PredictionContextCache;
import org.antlr.v4.runtime.dfa.DFA;

import java.util.ArrayList;
import java.util.Collection;

public class LexerInterpreter extends Lexer {
	protected final String grammarFileName;
	protected final ATN atn;

	@Deprecated
	protected final String[] tokenNames;
	protected final String[] ruleNames;
	protected final String[] channelNames;
	protected final String[] modeNames;


	private final Vocabulary vocabulary;

	protected final DFA[] _decisionToDFA;
	protected final PredictionContextCache _sharedContextCache =
		new PredictionContextCache();

	@Deprecated
	public LexerInterpreter(String grammarFileName, Collection<String> tokenNames, Collection<String> ruleNames, Collection<String> modeNames, ATN atn, CharStream input) {
		this(grammarFileName, VocabularyImpl.fromTokenNames(tokenNames.toArray(new String[0])), ruleNames, new ArrayList<String>(), modeNames, atn, input);
	}

	@Deprecated
	public LexerInterpreter(String grammarFileName, Vocabulary vocabulary, Collection<String> ruleNames, Collection<String> modeNames, ATN atn, CharStream input) {
		this(grammarFileName, vocabulary, ruleNames, new ArrayList<String>(), modeNames, atn, input);
	}

	public LexerInterpreter(String grammarFileName, Vocabulary vocabulary, Collection<String> ruleNames, Collection<String> channelNames, Collection<String> modeNames, ATN atn, CharStream input) {
		super(input);

		if (atn.grammarType != ATNType.LEXER) {
			throw new IllegalArgumentException("The ATN must be a lexer ATN.");
		}

		this.grammarFileName = grammarFileName;
		this.atn = atn;
		this.tokenNames = new String[atn.maxTokenType];
		for (int i = 0; i < tokenNames.length; i++) {
			tokenNames[i] = vocabulary.getDisplayName(i);
		}

		this.ruleNames = ruleNames.toArray(new String[0]);
		this.channelNames = channelNames.toArray(new String[0]);
		this.modeNames = modeNames.toArray(new String[0]);
		this.vocabulary = vocabulary;

		this._decisionToDFA = new DFA[atn.getNumberOfDecisions()];
		for (int i = 0; i < _decisionToDFA.length; i++) {
			_decisionToDFA[i] = new DFA(atn.getDecisionState(i), i);
		}
		this._interp = new LexerATNSimulator(this,atn,_decisionToDFA,_sharedContextCache);
	}

	@Override
	public ATN getATN() {
		return atn;
	}

	@Override
	public String getGrammarFileName() {
		return grammarFileName;
	}

	@Override
	@Deprecated
	public String[] getTokenNames() {
		return tokenNames;
	}

	@Override
	public String[] getRuleNames() {
		return ruleNames;
	}

	@Override
	public String[] getChannelNames() {
		return channelNames;
	}

	@Override
	public String[] getModeNames() {
		return modeNames;
	}

	@Override
	public Vocabulary getVocabulary() {
		if (vocabulary != null) {
			return vocabulary;
		}

		return super.getVocabulary();
	}
}

⏎ org/antlr/v4/runtime/LexerInterpreter.java

Or download all of them as a single archive file:

File name: antlr-runtime-4.10.1-sources.jar
File size: 308953 bytes
Release date: 2022-04-15
Download 

⇒ ANTLR Tool Source Code

⇐ What Is ANTLR Parser Generator

⇑ Download and Review ANTLR Parser Generator

⇑⇑ FAQ for ANTLR Parser Generator