Usage

var iterIntersectionByHash = require( '@stdlib/iter-intersection-by-hash' );

iterIntersectionByHash( iter0, ...iterator, hashFcn[, thisArg] )

Returns an iterator which returns the intersection of two or more iterators according to a hash function.

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

function hashFcn( v ) {
    return v.toString();
}

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

var it = iterIntersectionByHash( it1, it2, hashFcn );
// 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.

A hash function is provided one argument:

• v: the current iterated value

To set the execution context of the hash function, provide a thisArg.

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

function hashFcn( v ) {
    this.count += 1;
    return JSON.stringify( v );
}

var values1 = [
    { 'v': 2 },
    { 'v': 1 },
    { 'v': 1 },
    { 'v': 2 }
];
var values2 = [
    { 'v': 4 },
    { 'v': 3 },
    { 'v': 4 },
    { 'v': 3 },
    { 'v': 1 },
    { 'v': 2 }
];

var it1 = array2iterator( values1 );
var it2 = array2iterator( values2 );

var ctx = {
    'count': 0
};

var it = iterIntersectionByHash( it1, it2, hashFcn, ctx );
// returns <Object>

var v = it.next().value;
// returns { 'v': 2 }

v = it.next().value;
// returns { 'v': 1 }

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

bool = ( ctx.count > 0 );
// returns true