/** * @license Apache-2.0 * * Copyright (c) 2018 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 validate = require( './validate.js' ); var returnValues = require( './return_values.js' ); var returnIndices = require( './return_indices.js' ); var returnPairs = require( './return_pairs.js' ); // MAIN // /** * Splits values into two groups. * * @param {Collection} collection - input collection * @param {Options} [options] - function options * @param {string} [options.returns="values"] - if `values`, values are returned; if `indices`, indices are returned; if `*`, both indices and values are returned * @param {Collection} filter - collection indicating which group an element in the input collection belongs to * @throws {TypeError} first argument must be a collection * @throws {TypeError} options argument must be an object * @throws {TypeError} must provide valid options * @throws {TypeError} last argument must be a collection * @throws {RangeError} first and last arguments must be the same length * @returns {(Array|ArrayArray)} results * * @example * var arr = [ 'beep', 'boop', 'foo', 'bar' ]; * var filter = [ true, true, false, true ]; * * var out = bifurcate( arr, filter ); * // returns [ [ 'beep', 'boop', 'bar' ], [ 'foo' ] ] * * @example * var arr = [ 'beep', 'boop', 'foo', 'bar' ]; * var filter = [ true, true, false, true ]; * * var opts = { * 'returns': 'indices' * }; * * var out = bifurcate( arr, opts, filter ); * // returns [ [ 0, 1, 3 ], [ 2 ] ] * * @example * var arr = [ 'beep', 'boop', 'foo', 'bar' ]; * var filter = [ true, true, false, true ]; * * var opts = { * 'returns': '*' * }; * * var out = bifurcate( arr, opts, filter ); * // returns [ [ [ 0, 'beep' ], [ 1, 'boop' ], [ 3, 'bar' ] ], [ [ 2, 'foo' ] ] ] */ function bifurcate( collection, options, filter ) { var opts; var err; var f; if ( !isCollection( collection ) ) { throw new TypeError( 'invalid argument. First argument must be a collection. Value: `'+collection+'`.' ); } opts = { 'returns': 'values' }; if ( arguments.length === 2 ) { f = options; } else { err = validate( opts, options ); if ( err ) { throw err; } f = filter; } if ( !isCollection( f ) ) { throw new TypeError( 'invalid argument. Last argument must be a collection. Value: `'+f+'`.' ); } if ( collection.length !== f.length ) { throw new RangeError( 'invalid arguments. First and last arguments must be the same length.' ); } if ( opts.returns === 'values' ) { return returnValues( collection, f ); } if ( opts.returns === 'indices' ) { return returnIndices( collection, f ); } return returnPairs( collection, f ); } // EXPORTS // module.exports = bifurcate;