README
iterUnshift
Create an iterator which prepends values to the beginning of a provided iterator.
Installation
npm install @stdlib/iter-unshift
Usage
var iterUnshift = require( '@stdlib/iter-unshift' );
iterUnshift( iterator, ...items )
Returns an iterator which prepends values to the beginning of a provided iterator
.
var array2iterator = require( '@stdlib/array-to-iterator' );
var it = iterUnshift( array2iterator( [ 1, 2 ] ), 3, 4 );
// returns <Object>
var v = it.next().value;
// returns 3
v = it.next().value;
// returns 4
v = it.next().value;
// returns 1
v = it.next().value;
// returns 2
var bool = it.next().done;
// returns true
The returned iterator protocol-compliant object has the following properties:
- next: function which returns an iterator protocol-compliant object containing the next iterated value (if one exists) assigned to a
value
property and adone
property having aboolean
value indicating whether the iterator is finished. - return: function which closes an iterator and returns a single (optional) argument in an iterator protocol-compliant object.
Notes
Examples
var randu = require( '@stdlib/random-iter-randu' );
var iterUnshift = require( '@stdlib/iter-unshift' );
// Create a seeded iterator for generating pseudorandom numbers:
var rand = randu({
'seed': 1234,
'iter': 10
});
// Create an iterator with prepended values:
var it = iterUnshift( rand, 'beep', 'boop' );
// Perform manual iteration...
var v;
while ( true ) {
v = it.next();
if ( v.done ) {
break;
}
console.log( v.value );
}
Notice
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.
Community
License
See LICENSE.
Copyright
Copyright © 2016-2021. The Stdlib Authors.