Iterators

Standard library iterator utilities.

Usage

var ns = require( '@stdlib/iter' );

ns

Standard library iterator utilities.

var objectKeys = require( '@stdlib/utils/keys' );

var keys = objectKeys( ns );
// e.g., returns [ 'iterAny', 'iterAnyBy', ... ]

Examples

var objectKeys = require( '@stdlib/utils/keys' );
var uncapitalize = require( '@stdlib/string/uncapitalize' );
var replace = require( '@stdlib/string/replace' );
var contains = require( '@stdlib/assert/contains' );
var randu = require( '@stdlib/random/iter/randu' );
var ns = require( '@stdlib/iter' );

// Create a fluent interface for chaining together iterator operations...

// Retrieve all the iterator utility names:
var keys = objectKeys( ns );

// Define a list of utilities to exclude from the fluent API:
var exclude = [ 'iterFlow', 'iterPipeline', 'iterThunk' ];

// Map each utility name to a fluent interface method...
var methods = {};
var key;
var k;
var i;
for ( i = 0; i < keys.length; i++ ) {
    key = keys[ i ];
    if ( contains( exclude, key ) ) {
        continue;
    }
    k = uncapitalize( replace( key, /^iter/, '' ) );
    methods[ k ] = ns[ key ];
}

// Create a fluent interface:
var FluentIterator = ns.iterFlow( methods );

// Create a new fluent interface iterator:
var it1 = new FluentIterator( randu() );

// Define a predicate function for filtering values:
function predicate( v ) {
    return ( v > 0.25 && v < 0.75 );
}

// Define a function which transforms iterated values:
function transform( v ) {
    return v * 10.0;
}

// Define a function to be invoked for each iterated value:
function log( v ) {
    console.log( v );
}

// Chain together a sequence of operations:
var it2 = it1.filter( predicate )
    .map( transform )
    .head( 10 )
    .forEach( log );

// Perform manual iteration...
var v;
while ( true ) {
    v = it2.next();
    if ( v.done ) {
        break;
    }
}