iterCounter

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

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 );
}