view graal/com.oracle.truffle.ruby.runtime/src/com/oracle/truffle/ruby/runtime/NilPlaceholder.java @ 14094:3f27e57439ed

Truffle/Instrumentation: significant rearrangement (including moved class) and extension of the Truffle Instrumentation Framework. New interfaces include DebugContext (which can be attached to the ExecutionContext), through which access is provided to possibly language-specific (a) node instrumentation, (b) debug services manager, (c) notification when programs halt, (d) display of language values, and (e) display of variable identifiers.
author Michael Van De Vanter <michael.van.de.vanter@oracle.com>
date Mon, 03 Feb 2014 20:58:23 -0800
parents 0fbee3eb71f0
children
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/*
 * Copyright (c) 2013 Oracle and/or its affiliates. All rights reserved. This
 * code is released under a tri EPL/GPL/LGPL license. You can use it,
 * redistribute it and/or modify it under the terms of the:
 *
 * Eclipse Public License version 1.0
 * GNU General Public License version 2
 * GNU Lesser General Public License version 2.1
 */
package com.oracle.truffle.ruby.runtime;

/**
 * Represents the Ruby {@code Nil} object, but without being a full Ruby object. This allows us to
 * have a simple values that is {@code nil}, but more readily available than the particular instance
 * for a context.
 */
public final class NilPlaceholder {

    public static final NilPlaceholder INSTANCE = new NilPlaceholder();

    private NilPlaceholder() {
    }

    @Override
    public String toString() {
        return "";
    }

}