@stdlib/iter-constant v0.2.1
iterConstant
Create an iterator which always returns the same value.
Installation
npm install @stdlib/iter-constant
Usage
var iterConstant = require( '@stdlib/iter-constant' );
iterConstant( value[, options] )
Returns an iterator which always returns the same value.
var it = iterConstant( 3.14 );
// returns <Object>
var v = it.next().value;
// returns 3.14
v = it.next().value;
// returns 3.14
v = it.next().value;
// returns 3.14
// ...
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.
The function supports the following options
:
- iter: number of iterations. Default:
1e308
.
By default, the function returns an infinite iterator (i.e., an iterator which never ends). To limit the number of iterations, set the iter
option.
var opts = {
'iter': 2
};
var it = iterConstant( 3.14, opts );
// returns <Object>
var v = it.next().value;
// returns 3.14
v = it.next().value;
// returns 3.14
var bool = it.next().done;
// returns true
Notes
When provided an
object
reference, the returned iterator always returns the same reference.var arr = [ 1, 2, 3, 4 ]; var it = iterConstant( arr ); // returns <Object> var v1 = it.next().value; // returns [ 1, 2, 3, 4 ] var bool = ( v1 === arr ); // returns true var v2 = it.next().value; // returns [ 1, 2, 3, 4 ] bool = ( v2 === arr ); // returns true // ...
To avoid unwanted
object
mutation, copy a providedvalue
before creating an iterator.If an environment supports
Symbol.iterator
, the returned iterator is iterable.
Examples
var randu = require( '@stdlib/random-base-randu' );
var iterConstant = require( '@stdlib/iter-constant' );
// Create an iterator:
var opts = {
'iter': 10
};
var it = iterConstant( randu(), opts );
// Perform manual iteration...
var v;
while ( true ) {
v = it.next();
if ( v.done ) {
break;
}
console.log( v.value );
}
See Also
@stdlib/utils-constant-function
: constant function.
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.