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/misc/Pair.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.misc;

import java.io.Serializable;

public class Pair<A,B> implements Serializable {
	public final A a;
	public final B b;

	public Pair(A a, B b) {
		this.a = a;
		this.b = b;
	}

	@Override
	public boolean equals(Object obj) {
		if (obj == this) {
			return true;
		}
		else if (!(obj instanceof Pair<?, ?>)) {
			return false;
		}

		Pair<?, ?> other = (Pair<?, ?>)obj;
		return ObjectEqualityComparator.INSTANCE.equals(a, other.a)
			&& ObjectEqualityComparator.INSTANCE.equals(b, other.b);
	}

	@Override
	public int hashCode() {
		int hash = MurmurHash.initialize();
		hash = MurmurHash.update(hash, a);
		hash = MurmurHash.update(hash, b);
		return MurmurHash.finish(hash, 2);
	}

	@Override
	public String toString() {
		return String.format("(%s, %s)", a, b);
	}
}

⏎ org/antlr/v4/runtime/misc/Pair.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