@stdlib/iter

Standard iterator utilities.

Usage no npm install needed!

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README

Iterators

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Standard library iterator utilities.

Installation

npm install @stdlib/iter

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;
    }
}

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.

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License

See LICENSE.

Copyright

Copyright © 2016-2021. The Stdlib Authors.