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