diff --git a/spec.emu b/spec.emu index b60a2ec..7a76f8d 100644 --- a/spec.emu +++ b/spec.emu @@ -176,6 +176,81 @@ contributors: Mark S. Miller, Richard Gibson

TypedArray Objects

+ +

Properties of the %TypedArray% Intrinsic Object

+

The %TypedArray% intrinsic object:

+ + + +

%TypedArray%.from ( _source_ [ , _mapper_ [ , _thisArg_ ] ] )

+

This method performs the following steps when called:

+ + 1. Let _C_ be the *this* value. + 1. If IsConstructor(_C_) is *false*, throw a *TypeError* exception. + 1. If _mapper_ is *undefined*, then + 1. Let _mapping_ be *false*. + 1. Else, + 1. If IsCallable(_mapper_) is *false*, throw a *TypeError* exception. + 1. Let _mapping_ be *true*. + 1. Let _usingIterator_ be ? GetMethod(_source_, %Symbol.iterator%). + 1. If _usingIterator_ is not *undefined*, then + 1. Let _values_ be ? IteratorToList(? GetIteratorFromMethod(_source_, _usingIterator_)). + 1. Let _len_ be the number of elements in _values_. + 1. Let _targetObj_ be ? TypedArrayCreateFromConstructor(_C_, « 𝔽(_len_) », ~write~). + 1. Let _k_ be 0. + 1. Repeat, while _k_ < _len_, + 1. Let _Pk_ be ! ToString(𝔽(_k_)). + 1. Let _kValue_ be the first element of _values_. + 1. Remove the first element from _values_. + 1. If _mapping_ is *true*, then + 1. Let _mappedValue_ be ? Call(_mapper_, _thisArg_, « _kValue_, 𝔽(_k_) »). + 1. Else, + 1. Let _mappedValue_ be _kValue_. + 1. Perform ? Set(_targetObj_, _Pk_, _mappedValue_, *true*). + 1. Set _k_ to _k_ + 1. + 1. Assert: _values_ is now an empty List. + 1. Return _targetObj_. + 1. NOTE: _source_ is not an iterable object, so assume it is already an array-like object. + 1. Let _arrayLike_ be ! ToObject(_source_). + 1. Let _len_ be ? LengthOfArrayLike(_arrayLike_). + 1. Let _targetObj_ be ? TypedArrayCreateFromConstructor(_C_, « 𝔽(_len_) », ~write~). + 1. Let _k_ be 0. + 1. Repeat, while _k_ < _len_, + 1. Let _Pk_ be ! ToString(𝔽(_k_)). + 1. Let _kValue_ be ? Get(_arrayLike_, _Pk_). + 1. If _mapping_ is *true*, then + 1. Let _mappedValue_ be ? Call(_mapper_, _thisArg_, « _kValue_, 𝔽(_k_) »). + 1. Else, + 1. Let _mappedValue_ be _kValue_. + 1. Perform ? Set(_targetObj_, _Pk_, _mappedValue_, *true*). + 1. Set _k_ to _k_ + 1. + 1. Return _targetObj_. + + + + +

%TypedArray%.of ( ..._items_ )

+

This method performs the following steps when called:

+ + 1. Let _len_ be the number of elements in _items_. + 1. Let _C_ be the *this* value. + 1. If IsConstructor(_C_) is *false*, throw a *TypeError* exception. + 1. Let _newObj_ be ? TypedArrayCreateFromConstructor(_C_, « 𝔽(_len_) », ~write~). + 1. Let _k_ be 0. + 1. Repeat, while _k_ < _len_, + 1. Let _kValue_ be _items_[_k_]. + 1. Let _Pk_ be ! ToString(𝔽(_k_)). + 1. Perform ? Set(_newObj_, _Pk_, _kValue_, *true*). + 1. Set _k_ to _k_ + 1. + 1. Return _newObj_. + + + +

Properties of the %TypedArray% Prototype Object

@@ -262,6 +337,60 @@ contributors: Mark S. Miller, Richard Gibson + +

%TypedArray%.prototype.filter ( _callback_ [ , _thisArg_ ] )

+

The interpretation and use of the arguments of this method are the same as for `Array.prototype.filter` as defined in .

+

This method performs the following steps when called:

+ + 1. Let _O_ be the *this* value. + 1. Let _taRecord_ be ? ValidateTypedArray(_O_, ~seq-cst~). + 1. Let _len_ be TypedArrayLength(_taRecord_). + 1. If IsCallable(_callback_) is *false*, throw a *TypeError* exception. + 1. Let _kept_ be a new empty List. + 1. Let _captured_ be 0. + 1. Let _k_ be 0. + 1. Repeat, while _k_ < _len_, + 1. Let _Pk_ be ! ToString(𝔽(_k_)). + 1. Let _kValue_ be ! Get(_O_, _Pk_). + 1. Let _selected_ be ToBoolean(? Call(_callback_, _thisArg_, « _kValue_, 𝔽(_k_), _O_ »)). + 1. If _selected_ is *true*, then + 1. Append _kValue_ to _kept_. + 1. Set _captured_ to _captured_ + 1. + 1. Set _k_ to _k_ + 1. + 1. Let _A_ be ? TypedArraySpeciesCreate(_O_, « 𝔽(_captured_) », ~write~). + 1. Assert: IsImmutableBuffer(_A_.[[ViewedArrayBuffer]]) is *false*. + 1. Let _n_ be 0. + 1. For each element _e_ of _kept_, do + 1. Perform ! Set(_A_, ! ToString(𝔽(_n_)), _e_, *true*). + 1. Set _n_ to _n_ + 1. + 1. Return _A_. + +

This method is not generic. The *this* value must be an object with a [[TypedArrayName]] internal slot.

+ + + +

%TypedArray%.prototype.map ( _callback_ [ , _thisArg_ ] )

+

The interpretation and use of the arguments of this method are the same as for `Array.prototype.map` as defined in .

+

This method performs the following steps when called:

+ + 1. Let _O_ be the *this* value. + 1. Let _taRecord_ be ? ValidateTypedArray(_O_, ~seq-cst~). + 1. Let _len_ be TypedArrayLength(_taRecord_). + 1. If IsCallable(_callback_) is *false*, throw a *TypeError* exception. + 1. Let _A_ be ? TypedArraySpeciesCreate(_O_, « 𝔽(_len_) », ~write~). + 1. Assert: IsImmutableBuffer(_A_.[[ViewedArrayBuffer]]) is *false*. + 1. Let _k_ be 0. + 1. Repeat, while _k_ < _len_, + 1. Let _Pk_ be ! ToString(𝔽(_k_)). + 1. Let _kValue_ be ! Get(_O_, _Pk_). + 1. Let _mappedValue_ be ? Call(_callback_, _thisArg_, « _kValue_, 𝔽(_k_), _O_ »). + 1. Perform ? Set(_A_, _Pk_, _mappedValue_, *true*). + 1. Set _k_ to _k_ + 1. + 1. Return _A_. + +

This method is not generic. The *this* value must be an object with a [[TypedArrayName]] internal slot.

+ +

%TypedArray%.prototype.reverse ( )

The interpretation and use of the arguments of this method are the same as for `Array.prototype.reverse` as defined in .

@@ -307,6 +436,60 @@ contributors: Mark S. Miller, Richard Gibson

This method is not generic. The *this* value must be an object with a [[TypedArrayName]] internal slot.

 + +

%TypedArray%.prototype.slice ( _start_, _end_ )

+

The interpretation and use of the arguments of this method are the same as for `Array.prototype.slice` as defined in .

+

This method performs the following steps when called:

+ + 1. Let _O_ be the *this* value. + 1. Let _taRecord_ be ? ValidateTypedArray(_O_, ~seq-cst~). + 1. Let _srcArrayLength_ be TypedArrayLength(_taRecord_). + 1. Let _relativeStart_ be ? ToIntegerOrInfinity(_start_). + 1. If _relativeStart_ = -∞, let _startIndex_ be 0. + 1. Else if _relativeStart_ < 0, let _startIndex_ be max(_srcArrayLength_ + _relativeStart_, 0). + 1. Else, let _startIndex_ be min(_relativeStart_, _srcArrayLength_). + 1. If _end_ is *undefined*, let _relativeEnd_ be _srcArrayLength_; else let _relativeEnd_ be ? ToIntegerOrInfinity(_end_). + 1. If _relativeEnd_ = -∞, let _endIndex_ be 0. + 1. Else if _relativeEnd_ < 0, let _endIndex_ be max(_srcArrayLength_ + _relativeEnd_, 0). + 1. Else, let _endIndex_ be min(_relativeEnd_, _srcArrayLength_). + 1. Let _countBytes_ be max(_endIndex_ - _startIndex_, 0). + 1. Let _A_ be ? TypedArraySpeciesCreate(_O_, « 𝔽(_countBytes_) », ~write~). + 1. Assert: IsImmutableBuffer(_A_.[[ViewedArrayBuffer]]) is *false*. + 1. If _countBytes_ > 0, then + 1. Set _taRecord_ to MakeTypedArrayWithBufferWitnessRecord(_O_, ~seq-cst~). + 1. If IsTypedArrayOutOfBounds(_taRecord_) is *true*, throw a *TypeError* exception. + 1. Set _endIndex_ to min(_endIndex_, TypedArrayLength(_taRecord_)). + 1. Set _countBytes_ to max(_endIndex_ - _startIndex_, 0). + 1. Let _srcType_ be TypedArrayElementType(_O_). + 1. Let _targetType_ be TypedArrayElementType(_A_). + 1. If _srcType_ is _targetType_, then + 1. NOTE: The transfer must be performed in a manner that preserves the bit-level encoding of the source data. + 1. Let _srcBuffer_ be _O_.[[ViewedArrayBuffer]]. + 1. Let _targetBuffer_ be _A_.[[ViewedArrayBuffer]]. + 1. Let _elementSize_ be TypedArrayElementSize(_O_). + 1. Let _srcByteOffset_ be _O_.[[ByteOffset]]. + 1. Let _srcByteIndex_ be (_startIndex_ × _elementSize_) + _srcByteOffset_. + 1. Let _targetByteIndex_ be _A_.[[ByteOffset]]. + 1. Let _endByteIndex_ be _targetByteIndex_ + (_countBytes_ × _elementSize_). + 1. Repeat, while _targetByteIndex_ < _endByteIndex_, + 1. Let _value_ be GetValueFromBuffer(_srcBuffer_, _srcByteIndex_, ~uint8~, *true*, ~unordered~). + 1. Perform SetValueInBuffer(_targetBuffer_, _targetByteIndex_, ~uint8~, _value_, *true*, ~unordered~). + 1. Set _srcByteIndex_ to _srcByteIndex_ + 1. + 1. Set _targetByteIndex_ to _targetByteIndex_ + 1. + 1. Else, + 1. Let _n_ be 0. + 1. Let _k_ be _startIndex_. + 1. Repeat, while _k_ < _endIndex_, + 1. Let _Pk_ be ! ToString(𝔽(_k_)). + 1. Let _kValue_ be ! Get(_O_, _Pk_). + 1. Perform ! Set(_A_, ! ToString(𝔽(_n_)), _kValue_, *true*). + 1. Set _k_ to _k_ + 1. + 1. Set _n_ to _n_ + 1. + 1. Return _A_. + +

This method is not generic. The *this* value must be an object with a [[TypedArrayName]] internal slot.

+ +

%TypedArray%.prototype.sort ( _comparator_ )

This is a distinct method that, except as described below, implements the same requirements as those of `Array.prototype.sort` as defined in . The implementation of this method may be optimized with the knowledge that the *this* value is an object that has a fixed length and whose integer-indexed properties are not sparse.

@@ -336,6 +519,54 @@ contributors: Mark S. Miller, Richard Gibson

Abstract Operations for TypedArray Objects

+ +

+ TypedArraySpeciesCreate ( + _exemplar_: a TypedArray, + _argumentList_: a List of ECMAScript language values, + optional _accessMode_: ~read~ or ~write~, + ): either a normal completion containing a TypedArray or a throw completion +

+
+
description
+
It is used to specify the creation of a new TypedArray using a constructor function that is derived from _exemplar_. Unlike ArraySpeciesCreate, which can create non-Array objects through the use of %Symbol.species%, this operation enforces that the constructor function creates an actual TypedArray.
+
+ + 1. If _accessMode_ is not present, set _accessMode_ to ~read~. + 1. Let _defaultConstructor_ be the intrinsic object associated with the constructor name _exemplar_.[[TypedArrayName]] in . + 1. Let _constructor_ be ? SpeciesConstructor(_exemplar_, _defaultConstructor_). + 1. Let _result_ be ? TypedArrayCreateFromConstructor(_constructor_, _argumentList_, _accessMode_). + 1. Assert: _result_ has [[TypedArrayName]] and [[ContentType]] internal slots. + 1. Assert: _result_ has all of the internal slots of a TypedArray instance (). + 1. If _result_.[[ContentType]] is not _exemplar_.[[ContentType]], throw a *TypeError* exception. + 1. Return _result_. + + + + +

+ TypedArrayCreateFromConstructor ( + _constructor_: a constructor, + _argumentList_: a List of ECMAScript language values, + optional _accessMode_: ~read~ or ~write~, + ): either a normal completion containing a TypedArray or a throw completion +

+
+
description
+
It is used to specify the creation of a new TypedArray using a constructor function.
+
+ + 1. If _accessMode_ is not present, set _accessMode_ to ~read~. + 1. Let _newTypedArray_ be ? Construct(_constructor_, _argumentList_). + 1. Let _taRecord_ be ? ValidateTypedArray(_newTypedArray_, ~seq-cst~, _accessMode_). + 1. If the number of elements in _argumentList_ is 1 and _argumentList_[0] is a Number, then + 1. If IsTypedArrayOutOfBounds(_taRecord_) is *true*, throw a *TypeError* exception. + 1. Let _length_ be TypedArrayLength(_taRecord_). + 1. If _length_ < ℝ(_argumentList_[0]), throw a *TypeError* exception. + 1. Return _newTypedArray_. + + +

ValidateTypedArray (