@stdlib/iter-pipeline-thunk
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    0.0.7 • Public • Published

    iterThunk

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    Create an iterator "thunk".

    Installation

    npm install @stdlib/iter-pipeline-thunk

    Usage

    var iterThunk = require( '@stdlib/iter-pipeline-thunk' );

    iterThunk( iterFcn[, ...args] )

    Returns an iterator "thunk".

    var array2iterator = require( '@stdlib/array-to-iterator' );
    var iterSome = require( '@stdlib/iter-some' );
    
    var thunk = iterThunk( iterSome, 3 );
    
    var arr = array2iterator( [ 0, 0, 1, 1, 1 ] );
    var bool = thunk( arr );
    // returns true
    
    arr = array2iterator( [ 0, 0, 1, 0, 1 ] );
    bool = thunk( arr );
    // returns false

    A provided iterator function should have the following function signature:

    function iterFcn( iterator[, ...args] ) {...}
    

    where

    The returned function expects a single argument

    and invokes iterFcn with the provided iterator and any previously provided args.

    Accordingly, this function implements left-to-right partial application with special consideration for functions which act upon iterator sequences.

    Notes

    • This function is useful within the context of iterator pipelines as a means to defer execution until a pipeline is ready for data flow.
    • The function evaluation context is always null.

    Examples

    var randu = require( '@stdlib/random-iter-randu' );
    var iterHead = require( '@stdlib/iter-head' );
    var iterMap = require( '@stdlib/iter-map' );
    var iterSome = require( '@stdlib/iter-some' );
    var iterPipeline = require( '@stdlib/iter-pipeline' );
    var iterThunk = require( '@stdlib/iter-pipeline-thunk' );
    
    function threshold( r ) {
        return ( r > 0.95 );
    }
    
    // Create a pipeline which tests whether at least 5% of values exceed a threshold:
    var p = iterPipeline(
        // Apply a threshold to iterated values:
        iterThunk( iterMap, threshold ),
    
        // Limit the sequence to 100 values:
        iterThunk( iterHead, 100 ),
    
        // Test whether at least 5 values exceed the threshold:
        iterThunk( iterSome, 5 )
    );
    
    // Define the number of random number sequences to analyze:
    var N = 100;
    
    // Initialize a counter for sequences satisfying the 5% threshold:
    var count = 0;
    
    // Perform analysis...
    var bool;
    var i;
    for ( i = 0; i < N; i++ ) {
        bool = p( randu() );
        if ( bool ) {
            count += 1;
        }
        console.log( bool );
    }
    console.log( '%d of %d', count, N );

    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-pipeline-thunk

    Homepage

    stdlib.io

    DownloadsWeekly Downloads

    29

    Version

    0.0.7

    License

    Apache-2.0

    Unpacked Size

    41 kB

    Total Files

    9

    Last publish

    Collaborators

    • stdlib-bot
    • kgryte
    • planeshifter
    • rreusser