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    @stdlib/iter-dedupe
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    0.0.6 • Public • Published

    iterDedupe

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    Create an iterator which removes consecutive duplicated values.

    Installation

    npm install @stdlib/iter-dedupe

    Usage

    var iterDedupe = require( '@stdlib/iter-dedupe' );

    iterDedupe( iterator[, limit] )

    Returns an iterator which removes consecutive duplicated values.

    var array2iterator = require( '@stdlib/array-to-iterator' );
    
    var it = iterDedupe( array2iterator( [ 1, 1, 2, 3, 3, 3, 4, 4 ] ) );
    // returns <Object>
    
    var v = it.next().value;
    // returns 1
    
    v = it.next().value;
    // returns 2
    
    v = it.next().value;
    // returns 3
    
    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.

    The returned iterator removes consecutive duplicated values and does not return globally unique values.

    var array2iterator = require( '@stdlib/array-to-iterator' );
    
    var it = iterDedupe( array2iterator( [ 1, 1, 2, 1, 1, 2 ] ) );
    // returns <Object>
    
    var v = it.next().value;
    // returns 1
    
    v = it.next().value;
    // returns 2
    
    v = it.next().value;
    // returns 1
    
    v = it.next().value;
    // returns 2
    
    var bool = it.next().done;
    // returns true

    To specify the number of allowed consecutive duplicated values, provide a second argument.

    var array2iterator = require( '@stdlib/array-to-iterator' );
    
    var it = iterDedupe( array2iterator( [ 1, 1, 2, 3, 3, 3, 3, 4, 4, 4 ] ), 2 );
    // returns <Object>
    
    var v = it.next().value;
    // returns 1
    
    v = it.next().value;
    // returns 1
    
    v = it.next().value;
    // returns 2
    
    v = it.next().value;
    // returns 3
    
    v = it.next().value;
    // returns 3
    
    v = it.next().value;
    // returns 4
    
    v = it.next().value;
    // returns 4
    
    var bool = it.next().done;
    // returns true

    Notes

    • NaN values are considered distinct.

      var array2iterator = require( '@stdlib/array-to-iterator' );
      
      var it = iterDedupe( array2iterator( [ NaN, NaN, NaN, NaN ] ) );
      // returns <Object>
      
      var v = it.next().value;
      // returns NaN
      
      v = it.next().value;
      // returns NaN
      
      v = it.next().value;
      // returns NaN
      
      v = it.next().value;
      // returns NaN
      
      var bool = it.next().done;
      // returns true
    • Uniqueness is determined according to strict equality. Accordingly, objects are not checked for deep equality.

      var array2iterator = require( '@stdlib/array-to-iterator' );
      
      var it = iterDedupe( array2iterator( [ {}, {}, {}, {} ] ) );
      // returns <Object>
      
      var v = it.next().value;
      // returns {}
      
      v = it.next().value;
      // returns {}
      
      v = it.next().value;
      // returns {}
      
      v = it.next().value;
      // returns {}
      
      var bool = it.next().done;
      // returns true
    • If an environment supports Symbol.iterator and a provided iterator is iterable, the returned iterator is iterable.

    Examples

    var randi = require( '@stdlib/random-iter-discrete-uniform' );
    var iterDedupe = require( '@stdlib/iter-dedupe' );
    
    // Create a seeded iterator for generating pseudorandom integers on the interval [1,3]:
    var rand = randi( 1, 3, {
        'seed': 1234,
        'iter': 100
    });
    
    // Create an iterator which limits "runs" to at most 3 values:
    var it = iterDedupe( rand, 3 );
    
    // Perform manual iteration...
    var v;
    while ( true ) {
        v = it.next();
        if ( v.done ) {
            break;
        }
        console.log( v.value );
    }

    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.

    Install

    npm i @stdlib/iter-dedupe

    Homepage

    stdlib.io

    DownloadsWeekly Downloads

    12

    Version

    0.0.6

    License

    Apache-2.0

    Unpacked Size

    45.1 kB

    Total Files

    9

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    Collaborators

    • stdlib-bot
    • kgryte
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    • rreusser