@stdlib/array/base/assert/contains/lib/factory.js

Arrays.

/**
* @license Apache-2.0
*
* Copyright (c) 2023 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 isCollection = require( '@stdlib/assert/is-collection' );
var isAccessorArray = require( './../../../../base/assert/is-accessor-array' );
var accessorGetter = require( './../../../../base/accessor-getter' );
var dtype = require( './../../../../dtype' );
var format = require( '@stdlib/string/format' );


// MAIN //

/**
* Returns a function to tests if an array contains a provided search value.
*
* @param {Collection} x - input array
* @throws {TypeError} must provide an array-like object
* @returns {Function} function to test if an array contains a search value
*
* @example
* var contains = factory( [ 1, 2, 3 ] );
* // returns <Function>
*
* var bool = contains( 2 );
* // returns true
*/
function factory( x ) {
	var get;
	var len;
	var dt;

	if ( !isCollection( x ) ) {
		throw new TypeError( format( 'invalid argument. Must provide an array-like object. Value: `%s`.', x ) );
	}
	// Resolve the input array data type:
	dt = dtype( x );

	// Resolve an accessor for retrieving input array elements:
	if ( isAccessorArray( x ) ) {
		get = accessorGetter( dt );
	}
	// Get the number of elements over which to iterate:
	len = x.length;

	return ( get === void 0 ) ? contains : accessors;
	/**
	* Tests if an array contains a provided search value.
	*
	* @private
	* @param {*} value - search value
	* @returns {boolean} boolean indicating if an array contains a search value
	*
	* @example
	* var out = contains( [ 1, 2, 3 ], 2 );
	* // returns true
	*/
	function contains( value ) {
		var i;
		for ( i = 0; i < len; i++ ) {
			if ( x[ i ] === value ) {
				return true;
			}
		}
		return false;
	}
	/**
	* Tests if an array contains a provided search value.
	*
	* @private
	* @param {*} value - search value
	* @returns {boolean} boolean indicating if an array contains a search value
	*/
	function accessors( value ) {
		var i;
		for ( i = 0; i < len; i++ ) {
			if ( get( x, i ) === value ) {
				return true;
			}
		}
		return false;
	}
}


// EXPORTS //

module.exports = factory;