@stdlib/iter-first
v0.2.2
Published
Return the first iterated value.
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iterFirst
Return the first iterated value.
Installation
npm install @stdlib/iter-first
Usage
var iterFirst = require( '@stdlib/iter-first' );
iterFirst( iterator )
Returns the first iterated value.
var array2iterator = require( '@stdlib/array-to-iterator' );
var arr = array2iterator( [ 1, 0, 0, 0, 0 ] );
var v = iterFirst( arr );
// returns 1
If a provided iterator
does not return any iterated values, the function returns undefined
.
var iterEmpty = require( '@stdlib/iter-empty' );
var v = iterFirst( iterEmpty() );
// returns undefined
Notes
- The function does not consume an entire iterator before returning.
Examples
var randu = require( '@stdlib/random-iter-randu' );
var iterMap = require( '@stdlib/iter-map' );
var iterFirst = require( '@stdlib/iter-first' );
function threshold( r ) {
return ( r > 0.95 );
}
// Create an iterator which generates uniformly distributed pseudorandom numbers:
var opts = {
'iter': 100
};
var riter = randu( opts );
// Create an iterator which applies a threshold to generated numbers:
var miter = iterMap( riter, threshold );
// Return the first threshold result:
var bool = iterFirst( miter );
// returns <boolean>
console.log( bool );
See Also
@stdlib/iter-head
: create an iterator which returns the firstn
values of a provided iterator.@stdlib/iter-last
: consume an entire iterator and return the last iterated value.@stdlib/iter-nth
: return the nth iterated 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 © 2016-2024. The Stdlib Authors.