Usage

var inmapRight = require( '@stdlib/utils-inmap-right' );

inmapRight( collection, fcn[, thisArg ] )

Invokes a function for each element in a collection and updates the collection in-place, iterating from right to left.

function scale( value, index ) {
    return value * index;
}

var arr = [ 1, 2, 3, 4 ];

var out = inmapRight( arr, scale );
// returns [ 0, 2, 6, 12 ]

var bool = ( out === arr );
// returns true

The invoked function is provided three arguments:

• value: collection element
• index: collection index
• collection: input collection

Basic support for dynamic collections is provided. Note, however, that index incrementation is not guaranteed to be monotonically decreasing.

var arr = [ 1, 2, 3, 4 ];
var i = 0;

function scale1( value, index, collection ) {
    i += 1;
    if ( index === 0 && collection.length < 10 ) {
        collection.unshift( i+1 );
    }
    return value * index;
}

var out = inmapRight( arr, scale1 );
// returns [ 0, 0, 0, 0, 0, 0, 0, 2, 6, 12 ]

function scale2( value, index, collection ) {
    collection.shift();
    return value * index;
}

arr = [ 1, 2, 3, 4 ];

out = inmapRight( arr, scale2 );
// returns [ 3, 12 ]

To set the function execution context, provide a thisArg.

function sum( value ) {
    this.sum += value;
    this.count += 1;
    return value;
}

var arr = [ 1, 2, 3, 4 ];

var context = {
    'sum': 0,
    'count': 0
};

var out = inmapRight( arr, sum, context );
// returns [ 1, 2, 3, 4 ]

var mean = context.sum / context.count;
// returns 2.5