@stdlib/iter-counter NPM

iterCounter

Create an iterator which iteratively computes the number of iterated values.

Installation

npm install @stdlib/iter-counter

Usage

var iterCounter = require( '@stdlib/iter-counter' );

iterCounter( iterator )

Returns an iterator which iteratively computes the number of iterated values (i.e., the cumulative count).

var array2iterator = require( '@stdlib/array-to-iterator' );

var it = iterCounter( array2iterator( [ 10, 20, 30, 40 ] ) );
// returns <Object>

var v = it.next().value;
// returns 1

v = it.next().value;
// returns 2

v = it.next().value;
// returns 3

// ...

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 a done property having a boolean 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

If an environment supports Symbol.iterator and a provided iterator is iterable, the returned iterator is iterable.

Examples

var randu = require( '@stdlib/random-iter-randu' );
var iterCounter = require( '@stdlib/iter-counter' );

// Create a seeded iterator for generating pseudorandom numbers:
var rand = randu({
    'seed': 1234,
    'iter': 10
});

// Create an iterator which iteratively computes the number of iterated values:
var it = iterCounter( rand );

// 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.