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Create an iterator which returns the intersection of two or more iterators.

npm install @stdlib/iter-intersection

Alternatively,

• To load the package in a website via a script tag without installation and bundlers, use the ES Module available on the esm branch (see README).
• If you are using Deno, visit the deno branch (see README for usage intructions).
• For use in Observable, or in browser/node environments, use the Universal Module Definition (UMD) build available on the umd branch (see README).

The branches.md file summarizes the available branches and displays a diagram illustrating their relationships.

To view installation and usage instructions specific to each branch build, be sure to explicitly navigate to the respective README files on each branch, as linked to above.

var iterIntersection = require( '@stdlib/iter-intersection' );

Returns an iterator which returns the intersection of two or more iterators.

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

var it1 = array2iterator( [ 2, 1, 1, 2, 4 ] );
var it2 = array2iterator( [ 3, 4, 3 ] );

var it = iterIntersection( it1, it2 );
// returns <Object>

var v = it.next().value;
// returns 4

var bool = it.next().done;
// returns true

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.

• Value "uniqueness" is determined according to strict equality.
• A returned iterator internally buffers unique values and, thus, has O(N) memory requirements, where N is the length of the first iterator.
• Do not provide iterators having infinite length.
• If an environment supports Symbol.iterator and all provided iterators are iterable, the returned iterator is iterable.

var discreteUniform = require( '@stdlib/random-iter-discrete-uniform' );
var iterIntersection = require( '@stdlib/iter-intersection' );

// Create seeded iterators which can generate 1000 pseudorandom numbers:
var rand1 = discreteUniform( 1, 10, {
    'seed': 1234,
    'iter': 1000
});
var rand2 = discreteUniform( 6, 15, {
    'seed': 1234,
    'iter': 1000
});

// Create an iterator which returns the intersection of the seeded iterators:
var it = iterIntersection( rand1, rand2 );

// Perform manual iteration...
var v;
while ( true ) {
    v = it.next();
    if ( v.done ) {
        break;
    }
    console.log( v.value );
}

• @stdlib/iter-intersection-by-hash: create an iterator which returns the intersection of two or more iterators according to a hash function.
• @stdlib/iter-union: create an iterator which returns the union of two or more iterators.
• @stdlib/iter-unique: create an iterator which returns unique values.

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.

See LICENSE.

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