Source/JavaScriptCore/runtime/MatchResult.h

/*
 * Copyright (C) 2012, 2016 Apple Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
 */

#pragma once

#include "SlowPathReturnType.h"
#include <wtf/NotFound.h>
#include <wtf/PrintStream.h>

namespace JSC {

struct MatchResult {
    constexpr MatchResult() = default;

    ALWAYS_INLINE MatchResult(size_t start, size_t end)
        : start(start)
        , end(end)
    {
    }

    ALWAYS_INLINE MatchResult(SlowPathReturnType match)
    {
        decodeResult(match, start, end);
    }

    ALWAYS_INLINE static constexpr MatchResult failed()
    {
        return MatchResult();
    }

    ALWAYS_INLINE explicit operator bool() const
    {
        return start != WTF::notFound;
    }

    ALWAYS_INLINE bool empty()
    {
        return start == end;
    }
    
    void dump(PrintStream&) const;

    size_t start { WTF::notFound };
    size_t end { 0 };
};

#if ENABLE(JIT)
static_assert(sizeof(SlowPathReturnType) == 2 * sizeof(size_t), "https://bugs.webkit.org/show_bug.cgi?id=198518#c11");
static_assert(sizeof(MatchResult) == sizeof(SlowPathReturnType), "Match result and SlowPathReturnType should be the same size");
#endif

} // namespace JSC