192 lines
4.3 KiB
Markdown
192 lines
4.3 KiB
Markdown
<!--
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@license Apache-2.0
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Copyright (c) 2021 The Stdlib Authors.
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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-->
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# DataView
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> [Constructor][mdn-dataview] which returns a data view representing a provided array buffer.
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<!-- Section to include introductory text. Make sure to keep an empty line after the intro `section` element and another before the `/section` close. -->
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<section class="intro">
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</section>
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<!-- /.intro -->
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<!-- Package usage documentation. -->
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<section class="usage">
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## Usage
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```javascript
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var DataView = require( '@stdlib/array/dataview' );
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```
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#### DataView( buffer\[, byteOffset\[, byteLength]] )
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Returns a [`DataView`][mdn-dataview] representing a provided array buffer.
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<!-- eslint-disable stdlib/require-globals -->
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```javascript
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var ArrayBuffer = require( '@stdlib/array/buffer' );
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var buf = new ArrayBuffer( 5 );
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// returns <ArrayBuffer>
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var dv = new DataView( buf );
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// returns <DataView>
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```
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* * *
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### Properties
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#### DataView.prototype.buffer
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**Read-only** property which returns the underlying array buffer.
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<!-- eslint-disable stdlib/require-globals -->
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```javascript
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var ArrayBuffer = require( '@stdlib/array/buffer' );
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var buf1 = new ArrayBuffer( 5 );
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var dv = new DataView( buf1 );
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var buf2 = dv.buffer;
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// returns <ArrayBuffer>
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var bool = ( buf1 === buf2 );
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// returns true
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```
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#### DataView.prototype.byteLength
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**Read-only** property which returns the length (in bytes) of the [`DataView`][mdn-dataview].
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<!-- eslint-disable stdlib/require-globals -->
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```javascript
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var ArrayBuffer = require( '@stdlib/array/buffer' );
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var buf = new ArrayBuffer( 5 );
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var dv = new DataView( buf );
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var byteLength = dv.byteLength;
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// returns 5
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```
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#### DataView.prototype.byteOffset
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**Read-only** property which returns the number of bytes from the [`DataView`][mdn-dataview] to the start of the underlying array buffer.
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<!-- eslint-disable stdlib/require-globals -->
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```javascript
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var ArrayBuffer = require( '@stdlib/array/buffer' );
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var buf = new ArrayBuffer( 5 );
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var dv = new DataView( buf, 3 );
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var byteOffset = dv.byteOffset;
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// returns 3
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```
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* * *
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### Methods
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TODO: document methods
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</section>
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<!-- /.usage -->
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* * *
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<!-- Package usage notes. Make sure to keep an empty line after the `section` element and another before the `/section` close. -->
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<section class="notes">
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</section>
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<!-- /.notes -->
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<!-- Package usage examples. -->
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<section class="examples">
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## Examples
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<!-- eslint no-undef: "error" -->
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```javascript
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var IS_LITTLE_ENDIAN = require( '@stdlib/assert/is-little-endian' );
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var toBinaryString = require( '@stdlib/number/uint8/base/to-binary-string' );
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var randu = require( '@stdlib/random/base/randu' );
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var Uint8Array = require( '@stdlib/array/uint8' );
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var ArrayBuffer = require( '@stdlib/array/buffer' );
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var DataView = require( '@stdlib/array/dataview' );
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// Create a new ArrayBuffer:
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var buf = new ArrayBuffer( 64 );
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// Create a new DataView:
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var dv = new DataView( buf );
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// Set values in the view:
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var i;
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for ( i = 0; i < dv.byteLength/8; i++ ) {
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dv.setFloat64( i*8, randu()*100.0, IS_LITTLE_ENDIAN );
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}
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// Create a "bytes" view of the underlying array buffer:
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var bytes = new Uint8Array( dv.buffer );
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// Print the bytes:
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for ( i = 0; i < bytes.length; i++ ) {
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console.log( 'byte %d: %s', i, toBinaryString( bytes[ i ] ) );
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}
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```
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</section>
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<!-- /.examples -->
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<!-- Section to include cited references. If references are included, add a horizontal rule *before* the section. Make sure to keep an empty line after the `section` element and another before the `/section` close. -->
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<section class="references">
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</section>
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<!-- /.references -->
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<!-- Section for all links. Make sure to keep an empty line after the `section` element and another before the `/section` close. -->
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<section class="links">
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[mdn-dataview]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/DataView
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</section>
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<!-- /.links -->
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