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/* -*- 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/. */
/* Array-related operations. */
#ifndef js_Array_h
#define js_Array_h
#include <stddef.h> // size_t
#include <stdint.h> // uint32_t
#include "jstypes.h" // JS_PUBLIC_API
#include "js/TypeDecls.h"
namespace JS {
class HandleValueArray;
/**
* Create an Array from the current realm with the given contents.
*/
extern JS_PUBLIC_API JSObject* NewArrayObject(JSContext* cx,
const HandleValueArray& contents);
/**
* Create an Array from the current realm with the given length and allocate
* memory for all its elements. (The elements nonetheless will not exist as
* properties on the returned array until values have been assigned to them.)
*/
extern JS_PUBLIC_API JSObject* NewArrayObject(JSContext* cx, size_t length);
/**
* Determine whether |value| is an Array object or a wrapper around one. (An
* ES6 proxy whose target is an Array object, e.g.
* |var target = [], handler = {}; Proxy.revocable(target, handler).proxy|, is
* not considered to be an Array.)
*
* On success set |*isArray| accordingly and return true; on failure return
* false.
*/
extern JS_PUBLIC_API bool IsArrayObject(JSContext* cx, Handle<Value> value,
bool* isArray);
/**
* Determine whether |obj| is an Array object or a wrapper around one. (An
* ES6 proxy whose target is an Array object, e.g.
* |var target = [], handler = {}; Proxy.revocable(target, handler).proxy|, is
* not considered to be an Array.)
*
* On success set |*isArray| accordingly and return true; on failure return
* false.
*/
extern JS_PUBLIC_API bool IsArrayObject(JSContext* cx, Handle<JSObject*> obj,
bool* isArray);
/**
* Store |*lengthp = ToLength(obj.length)| and return true on success, else
* return false.
*
* If the length does not fit in |uint32_t|, an exception is reported and false
* is returned.
*
* |ToLength| converts its input to an integer usable to index an
* array-like object.
*
* If |obj| is an Array, this overall operation is the same as getting
* |obj.length|.
*/
extern JS_PUBLIC_API bool GetArrayLength(JSContext* cx, Handle<JSObject*> obj,
uint32_t* lengthp);
/**
* Perform |obj.length = length| as if in strict mode code, with a fast path for
* the case where |obj| is an Array.
*
* This operation is exactly and only assigning to a "length" property. In
* general, it can invoke an existing "length" setter, throw if the property is
* non-writable, or do anything else a property-set operation might do.
*/
extern JS_PUBLIC_API bool SetArrayLength(JSContext* cx, Handle<JSObject*> obj,
uint32_t length);
/**
* The answer to a successful query as to whether an object is an Array per
* ES6's internal |IsArray| operation (as exposed by |Array.isArray|).
*/
enum class IsArrayAnswer { Array, NotArray, RevokedProxy };
/**
* ES6 7.2.2.
*
* Returns false on failure, otherwise returns true and sets |*isArray|
* indicating whether the object passes ECMAScript's IsArray test. This is the
* same test performed by |Array.isArray|.
*
* This is NOT the same as asking whether |obj| is an Array or a wrapper around
* one. If |obj| is a proxy created by |Proxy.revocable()| and has been
* revoked, or if |obj| is a proxy whose target (at any number of hops) is a
* revoked proxy, this method throws a TypeError and returns false.
*/
extern JS_PUBLIC_API bool IsArray(JSContext* cx, Handle<JSObject*> obj,
bool* isArray);
/**
* Identical to IsArray above, but the nature of the object (if successfully
* determined) is communicated via |*answer|. In particular this method
* returns true and sets |*answer = IsArrayAnswer::RevokedProxy| when called on
* a revoked proxy.
*
* Most users will want the overload above, not this one.
*/
extern JS_PUBLIC_API bool IsArray(JSContext* cx, Handle<JSObject*> obj,
IsArrayAnswer* answer);
} // namespace JS
#endif // js_Array_h
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