Fill an array-like object view from right to left with values returned from an iterator.
APACHE-2.0 License
Fill an array-like object view from right to left with values returned from an iterator.
npm install @stdlib/iter-to-array-view-right
Alternatively,
script
tag without installation and bundlers, use the ES Module available on the esm
branch (see README).deno
branch (see README for usage intructions).umd
branch (see README).The branches.md file summarizes the available branches and displays a diagram illustrating their relationships.
To view installation and usage instructions specific to each branch build, be sure to explicitly navigate to the respective README files on each branch, as linked to above.
var iterator2arrayviewRight = require( '@stdlib/iter-to-array-view-right' );
Fills an array-like object
view from right to left with values returned from an iterator
.
var Uint8Array = require( '@stdlib/array-uint8' );
var array2iterator = require( '@stdlib/array-to-iterator' );
var iter = array2iterator( [ 1, 2, 3, 4 ] );
var arr = iterator2arrayviewRight( iter, new Uint8Array( 10 ) );
// returns <Uint8Array>[ 0, 0, 0, 0, 0, 0, 4, 3, 2, 1 ]
The begin
and end
arguments define the starting (inclusive) and ending (non-inclusive) indices of the array view. By default, the function begins filling from the last element of a provided array-like object
(i.e., from the "end"). To specify an alternative view end, provide an end
argument (zero-based and non-inclusive).
var Uint8Array = require( '@stdlib/array-uint8' );
var array2iterator = require( '@stdlib/array-to-iterator' );
var iter = array2iterator( [ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 ] );
var arr = iterator2arrayviewRight( iter, new Uint8Array( 10 ), 0, 4 );
// returns <Uint8Array>[ 4, 3, 2, 1, 0, 0, 0, 0, 0, 0 ]
If end
is less than 0
, the last view element is resolved relative to the last element of the provided array-like object
. For example, the following achieves the same behavior as the previous example
var Uint8Array = require( '@stdlib/array-uint8' );
var array2iterator = require( '@stdlib/array-to-iterator' );
var iter = array2iterator( [ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 ] );
var arr = iterator2arrayviewRight( iter, new Uint8Array( 10 ), 0, -6 );
// returns <Uint8Array>[ 4, 3, 2, 1, 0, 0, 0, 0, 0, 0 ]
By default, the function fills through the first element of the provided array-like object
. To specify an alternative view beginning, provide a begin
argument (zero-based and inclusive).
var Uint8Array = require( '@stdlib/array-uint8' );
var array2iterator = require( '@stdlib/array-to-iterator' );
var iter = array2iterator( [ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 ] );
var arr = iterator2arrayviewRight( iter, new Uint8Array( 10 ), 3 );
// returns <Uint8Array>[ 0, 0, 0, 7, 6, 5, 4, 3, 2, 1 ]
If begin
is less than 0
, the first view element index is resolved relative to the last element of the provided array-like object
. For example, the following achieves the same behavior as the previous example
var Uint8Array = require( '@stdlib/array-uint8' );
var array2iterator = require( '@stdlib/array-to-iterator' );
var iter = array2iterator( [ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 ] );
var arr = iterator2arrayviewRight( iter, new Uint8Array( 10 ), -7 );
// returns <Uint8Array>[ 0, 0, 0, 7, 6, 5, 4, 3, 2, 1 ]
To invoke a function for each iterated value, provide a callback function.
var Float64Array = require( '@stdlib/array-float64' );
var array2iterator = require( '@stdlib/array-to-iterator' );
function fcn( v ) {
return v * 10.0;
}
var iter = array2iterator( [ 1, 2, 3, 4 ] );
var arr = iterator2arrayviewRight( iter, new Float64Array( 4 ), fcn );
// returns <Float64Array>[ 40.0, 30.0, 20.0, 10.0 ]
The invoked function is provided three arguments:
var Uint8Array = require( '@stdlib/array-uint8' );
var array2iterator = require( '@stdlib/array-to-iterator' );
function fcn( v, i, n ) {
return v * (n+1);
}
var iter = array2iterator( [ 1, 2, 3, 4 ] );
var arr = iterator2arrayviewRight( iter, new Uint8Array( 4 ), fcn );
// returns <Uint8Array>[ 16, 9, 4, 1 ]
To set the callback function execution context, provide a thisArg
.
var Float64Array = require( '@stdlib/array-float64' );
var randu = require( '@stdlib/random-iter-randu' );
function fcn( v ) {
this.count += 1;
return v * 10.0;
}
var ctx = {
'count': 0
};
var arr = iterator2arrayviewRight( randu(), new Float64Array( 10 ), fcn, ctx );
// returns <Float64Array>
var count = ctx.count;
// returns 10
@stdlib/array-complex64
).var Float64Array = require( '@stdlib/array-float64' );
var randu = require( '@stdlib/random-iter-randu' );
var iterator2arrayviewRight = require( '@stdlib/iter-to-array-view-right' );
function scale( v, i, n ) {
return v * (n+1) * 10.0;
}
// Create an iterator for generating uniformly distributed pseudorandom numbers:
var it = randu();
// Fill an array view with scaled iterator values:
var arr = iterator2arrayviewRight( it, new Float64Array( 100 ), 40, 60, scale );
var i;
for ( i = 0; i < arr.length; i++ ) {
console.log( arr[ i ] );
}
@stdlib/array-from-iterator
: create (or fill) an array from an iterator.
@stdlib/array-to-view-iterator-right
: create an iterator from an array-like object view, iterating from right to left.
@stdlib/iter-to-array-view
: fill an array-like object view with values returned from an iterator.
This package is part of stdlib, a standard library for JavaScript and Node.js, with an emphasis on numerical and scientific computing. The library provides a collection of robust, high performance libraries for mathematics, statistics, streams, utilities, and more.
For more information on the project, filing bug reports and feature requests, and guidance on how to develop stdlib, see the main project repository.
See LICENSE.
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