@stdlib/array/base/cuany-by/lib/assign.js

Arrays.

/**
* @license Apache-2.0
*
* Copyright (c) 2024 The Stdlib Authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
*    http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/

'use strict';

// MODULES //

var arraylike2object = require( './../../../base/arraylike2object' );


// FUNCTIONS //

/**
* Cumulatively tests whether at least one element in a provided array passes a test implemented by a predicate function.
*
* @private
* @param {Collection} x - input array
* @param {Collection} y - output array
* @param {integer} stride - output array stride
* @param {NonNegativeInteger} offset - output array offset
* @param {Function} predicate - test function
* @param {*} thisArg - execution context
* @returns {Collection} output array
*
* @example
* function isPositive( v ) {
*     return v > 0;
* }
*
* var x = [ false, false, false, true, false  ];
* var y = [ false, null, false, null, false, null, false, null, false, null ];
*
* var out = indexed( x, y, 2, 0, isPositive );
* // returns [ false, null, false, null, false, null, true, null, true, null ]
*/
function indexed( x, y, stride, offset, predicate, thisArg ) {
	var flg;
	var io;
	var i;

	flg = false;
	io = offset;
	for ( i = 0; i < x.length; i++ ) {
		if ( !flg && predicate.call(thisArg, x[ i ], i, x ) ) {
			flg = true;
		}
		y[ io ] = flg;
		io += stride;
	}
	return y;
}

/**
* Cumulatively tests whether at least one element in a provided array passes a test implemented by a predicate function.
*
* @private
* @param {Object} x - input array object
* @param {Object} y - output array object
* @param {integer} stride - output array stride
* @param {NonNegativeInteger} offset - output array offset
* @param {Function} predicate - test function
* @param {*} thisArg - execution context
* @returns {Collection} output array
*
* @example
* var toAccessorArray = require( '@stdlib/array/base/to-accessor-array' );
* var arraylike2object = require( '@stdlib/array/base/arraylike2object' );
*
* function isPositive( v ) {
*     return v > 0;
* }
*
* var x = toAccessorArray( [ false, false, false, true, false ] );
* var y = toAccessorArray( [ false, null, false, null, false, null, false, null, false, null ] );
*
* var arr = accessors( arraylike2object( x ), arraylike2object( y ), 2, 0, isPositive );
*
* var v = y.get( 0 );
* // returns false
*
* v = y.get( 2 );
* // returns false
*
* v = y.get( 4 );
* // returns false
*
* v = y.get( 6 );
* // returns true
*
* v = y.get( 8 );
* // returns true
*/
function accessors( x, y, stride, offset, predicate, thisArg ) {
	var xdata;
	var ydata;
	var xget;
	var yset;
	var flg;
	var io;
	var i;

	xdata = x.data;
	ydata = y.data;

	xget = x.accessors[ 0 ];
	yset = y.accessors[ 1 ];

	flg = false;
	io = offset;
	for ( i = 0; i < xdata.length; i++ ) {
		if ( !flg && predicate.call( thisArg, xget( xdata, i ), i, x ) ) {
			flg = true;
		}
		yset( ydata, io, flg );
		io += stride;
	}
	return ydata;
}


// MAIN //

/**
* Cumulatively tests whether at least one element in a provided array passes a test implemented by a predicate function and assigns results to a provided output array.
*
* @param {Collection} x - input array
* @param {Collection} y - output array
* @param {integer} stride - output array stride
* @param {NonNegativeInteger} offset - output array offset
* @param {Function} predicate - test function
* @param {*} [thisArg] - execution context
* @returns {Collection} output array
*
* @example
* function isPositive( v ) {
*     return v > 0;
* }
*
* var x = [ 0, 0, 0, 1, 0 ];
* var y = [ false, null, false, null, false, null, false, null, false, null ];
*
* var out = assign( x, y, 2, 0, isPositive );
// returns [ false, null, false, null, false, null, true, null, true, null ]
*
* var bool = ( y === out );
* // returns true
*/
function assign( x, y, stride, offset, predicate, thisArg ) {
	var xo = arraylike2object( x );
	var yo = arraylike2object( y );

	if (
		xo.accessorProtocol ||
		yo.accessorProtocol
	) {
		return accessors( xo, yo, stride, offset, predicate, thisArg );
	}
	indexed( x, y, stride, offset, predicate, thisArg );
	return y;
}


// EXPORTS //

module.exports = assign;