gecko-dev/js/public/Equality.h

66 строки
2.2 KiB
C++

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
/* Equality operations. */
#ifndef js_Equality_h
#define js_Equality_h
#include "mozilla/FloatingPoint.h"
#include "jstypes.h" // JS_PUBLIC_API
#include "js/TypeDecls.h"
struct JS_PUBLIC_API JSContext;
namespace JS {
/**
* Store |v1 === v2| to |*equal| -- strict equality, which performs no
* conversions on |v1| or |v2| before comparing.
*
* This operation can fail only if an internal error occurs (e.g. OOM while
* linearizing a string value).
*/
extern JS_PUBLIC_API bool StrictlyEqual(JSContext* cx, JS::Handle<JS::Value> v1,
JS::Handle<JS::Value> v2, bool* equal);
/**
* Store |v1 == v2| to |*equal| -- loose equality, which may perform
* user-modifiable conversions on |v1| or |v2|.
*
* This operation can fail if a user-modifiable conversion fails *or* if an
* internal error occurs. (e.g. OOM while linearizing a string value).
*/
extern JS_PUBLIC_API bool LooselyEqual(JSContext* cx, JS::Handle<JS::Value> v1,
JS::Handle<JS::Value> v2, bool* equal);
/**
* Stores |SameValue(v1, v2)| to |*equal| -- using the SameValue operation
* defined in ECMAScript, initially exposed to script as |Object.is|. SameValue
* behaves identically to strict equality, except that it equates two NaN values
* and does not equate differently-signed zeroes. It performs no conversions on
* |v1| or |v2| before comparing.
*
* This operation can fail only if an internal error occurs (e.g. OOM while
* linearizing a string value).
*/
extern JS_PUBLIC_API bool SameValue(JSContext* cx, JS::Handle<JS::Value> v1,
JS::Handle<JS::Value> v2, bool* same);
/**
* Implements |SameValueZero(v1, v2)| for Number values |v1| and |v2|.
* SameValueZero equates NaNs, equal nonzero values, and zeroes without respect
* to their signs.
*/
static inline bool SameValueZero(double v1, double v2) {
return mozilla::EqualOrBothNaN(v1, v2);
}
} // namespace JS
#endif /* js_Equality_h */