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@stdlib/array

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/** * @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 isString = require( '@stdlib/assert/is-string' ).isPrimitive; var isNonNegativeInteger = require( '@stdlib/assert/is-nonnegative-integer' ).isPrimitive; var isComplexDataType = require( './../../base/assert/is-complex-floating-point-data-type' ); var isBooleanDataType = require( './../../base/assert/is-boolean-data-type' ); var isCollection = require( '@stdlib/assert/is-collection' ); var isArrayBuffer = require( '@stdlib/assert/is-arraybuffer' ); var isObject = require( '@stdlib/assert/is-object' ); var isFunction = require( '@stdlib/assert/is-function' ); var ctors = require( './../../ctors' ); var gfillBy = require( '@stdlib/blas/ext/base/gfill-by' ); var filledArray = require( './../../base/filled-by' ); var hasIteratorSymbolSupport = require( '@stdlib/assert/has-iterator-symbol-support' ); var ITERATOR_SYMBOL = require( '@stdlib/symbol/iterator' ); var iterLength = require( '@stdlib/iter/length' ); var defaults = require( './../../defaults' ); var format = require( '@stdlib/string/format' ); // VARIABLES // var HAS_ITERATOR_SYMBOL = hasIteratorSymbolSupport(); var DEFAULT_DTYPE = defaults.get( 'dtypes.default' ); // FUNCTIONS // /** * Creates a filled "generic" array from an iterator. * * @private * @param {Iterable} it - iterator * @param {Callback} clbk - callback function * @param {*} thisArg - callback function execution context * @returns {Array} filled array */ function filledArrayIterator( it, clbk, thisArg ) { var arr; var i; var v; arr = []; i = -1; while ( true ) { v = it.next(); if ( v.done ) { break; } i += 1; arr.push( clbk.call( thisArg, i ) ); } return arr; } /** * Fills an array exposing accessors for getting and setting array elements. * * @private * @param {Collection} arr - input array * @param {Callback} clbk - callback function * @param {*} thisArg - callback function execution context * @returns {Collection} input array */ function filledAccessors( arr, clbk, thisArg ) { var i; for ( i = 0; i < arr.length; i++ ) { arr.set( clbk.call( thisArg, i ), i ); } return arr; } // MAIN // /** * Creates a filled array according to a provided callback function. * * @param {(NonNegativeInteger|TypedArray|ArrayLikeObject|ArrayBuffer|Iterable)} [arg] - a length, typed array, array-like object, buffer, or iterable * @param {NonNegativeInteger} [byteOffset=0] - byte offset * @param {NonNegativeInteger} [length] - view length * @param {string} [dtype="float64"] - data type * @param {Callback} [clbk] - callback to invoke * @param {*} [thisArg] - callback execution context * @throws {TypeError} must provide a recognized data type * @throws {TypeError} must provide a length, typed array, array-like object, buffer, or iterable * @throws {TypeError} callback argument must be a function. * @throws {Error} creating a generic array from an `ArrayBuffer` is not supported * @returns {(TypedArray|Array)} array or typed array * * @example * var arr = filledarrayBy(); * // returns <Float64Array> * * @example * function clbk() { * return 1.0; * } * * var arr = filledarrayBy( 2, clbk ); * // returns <Float64Array>[ 1.0, 1.0 ] * * @example * function clbk() { * return 1.0; * } * * var arr = filledarrayBy( 2, 'float32', clbk ); * // returns <Float32Array>[ 1.0, 1.0 ] * * @example * function clbk() { * return 1.0; * } * * var arr = filledarrayBy( 2, 'generic', clbk ); * // returns [ 1.0, 1.0 ] * * @example * function clbk() { * return 1.0; * } * * var arr = filledarrayBy( [ 0.5, 0.5 ], clbk ); * // returns <Float64Array>[ 1.0, 1.0 ] * * @example * function clbk() { * return 1; * } * * var arr = filledarrayBy( [ 5, -3 ], 'int32', clbk ); * // returns <Int32Array>[ 1, 1 ] * * @example * function clbk1() { * return 10; * } * * function clbk2() { * return 1.0; * } * * var arr1 = filledarrayBy( [ 5, 3 ], 'int32', clbk1 ); * var arr2 = filledarrayBy( arr1, clbk2 ); * // returns <Float64Array>[ 1.0, 1.0 ] * * @example * function clbk1() { * return 1.0; * } * * function clbk2() { * return 2; * } * * var arr1 = filledarrayBy( [ 5, 3 ], 'int32', clbk1 ); * var arr2 = filledarrayBy( arr1, 'uint32', clbk2 ); * // returns <Uint32Array>[ 2, 2 ] * * @example * var ArrayBuffer = require( '@stdlib/array/buffer' ); * * function clbk() { * return 1.0; * } * * var buf = new ArrayBuffer( 16 ); * var arr = filledarrayBy( buf, clbk ); * // returns <Float64Array>[ 1.0, 1.0 ] * * @example * var ArrayBuffer = require( '@stdlib/array/buffer' ); * * function clbk() { * return 1.0; * } * * var buf = new ArrayBuffer( 16 ); * var arr = filledarrayBy( buf, 'float32', clbk ); * // returns <Float32Array>[ 1.0, 1.0, 1.0, 1.0 ] * * @example * var ArrayBuffer = require( '@stdlib/array/buffer' ); * * function clbk() { * return 1.0; * } * * var buf = new ArrayBuffer( 16 ); * var arr = filledarrayBy( buf, 8, clbk ); * // returns <Float64Array>[ 1.0 ] * * @example * var ArrayBuffer = require( '@stdlib/array/buffer' ); * * function clbk() { * return 1.0; * } * * var buf = new ArrayBuffer( 16 ); * var arr = filledarrayBy( buf, 8, 'float32', clbk ); * // returns <Float32Array>[ 1.0, 1.0 ] * * @example * var ArrayBuffer = require( '@stdlib/array/buffer' ); * * function clbk() { * return 1.0; * } * * var buf = new ArrayBuffer( 32 ); * var arr = filledarrayBy( buf, 8, 2, clbk ); * // returns <Float64Array>[ 1.0, 1.0 ] * * @example * var ArrayBuffer = require( '@stdlib/array/buffer' ); * * function clbk() { * return 1; * } * * var buf = new ArrayBuffer( 32 ); * var arr = filledarrayBy( buf, 8, 2, 'int32', clbk ); * // returns <Int32Array>[ 1, 1 ] */ function filledarrayBy() { var thisArg; var nargs; var dtype; var clbk; var ctor; var arr; var len; var arg; nargs = arguments.length; // If we weren't provided any arguments, return an empty array... if ( nargs === 0 ) { ctor = ctors( DEFAULT_DTYPE ); return new ctor( 0 ); } // Check if we were provided a dtype as the first argument... dtype = arguments[ 0 ]; if ( isString( dtype ) ) { // Invoking this function with arguments `f( dtype, clbk[, thisArg] )` is not allowed (otherwise, we'd need to also allow `f( clbk[, thisArg] )`)... if ( nargs > 1 ) { throw new TypeError( 'invalid arguments. Must provide a length, typed array, array-like object, or an iterable.' ); } ctor = ctors( dtype ); if ( ctor === null ) { throw new TypeError( format( 'invalid argument. Must provide a recognized data type. Value: `%s`.', dtype ) ); } // Return an empty array having the specified dtype: return new ctor( 0 ); } // For all other supported invocations, we need at least two arguments... if ( nargs < 2 ) { throw new TypeError( 'invalid arguments. Must provide a length, typed array, array-like object, or an iterable.' ); } // At this point, we need to do some argument juggling... nargs -= 1; // henceforth, the number of available arguments is `nargs+1` // Determine whether the last argument is a callback or "this" context... if ( isFunction( arguments[ nargs ] ) ) { // If the last argument is a function, we need to check the next-to-last argument, and, if the next-to-last argument is a function, assume that the next-to-last argument is the callback and the last argument is a "this" context... if ( isFunction( arguments[ nargs-1 ] ) ) { thisArg = arguments[ nargs ]; nargs -= 1; clbk = arguments[ nargs ]; // Check if we were provided only a callback and a "this" context.. if ( nargs === 0 ) { throw new TypeError( 'invalid arguments. Must provide a length, typed array, array-like object, or an iterable.' ); } } else { // "this" context is left undefined... clbk = arguments[ nargs ]; } } // If we were provided 3 or more arguments and the last argument was not a function, assume that we were provided a callback and a "this" context... else if ( nargs >= 2 ) { thisArg = arguments[ nargs ]; nargs -= 1; clbk = arguments[ nargs ]; if ( !isFunction( clbk ) ) { throw new TypeError( format( 'invalid argument. Callback argument must be a function. Value: `%s`.', clbk ) ); } } // If were were only provided 2 arguments and the last argument was not a function, we've been provided an insufficient number of arguments... else { throw new TypeError( 'invalid arguments. Must provide a length, typed array, array-like object, or an iterable.' ); } // Now that we've processed the callback arguments, let's continue working backward to see if we've been provided a `dtype` argument... nargs -= 1; if ( nargs >= 0 && isString( arguments[ nargs ] ) ) { dtype = arguments[ nargs ]; nargs -= 1; } else { dtype = DEFAULT_DTYPE; } ctor = ctors( dtype ); if ( ctor === null ) { throw new TypeError( format( 'invalid argument. Must provide a recognized data type. Value: `%s`.', dtype ) ); } // At this point, we've resolved the output array data type, and now we can actually create the output array... if ( dtype === 'generic' ) { arg = arguments[ 0 ]; if ( nargs === 0 ) { if ( isNonNegativeInteger( arg ) ) { len = arg; } else if ( isCollection( arg ) ) { len = arg.length; } if ( len !== void 0 ) { return filledArray( len, clbk, thisArg ); } if ( isArrayBuffer( arg ) ) { throw new Error( 'invalid arguments. Creating a generic array from an ArrayBuffer is not supported.' ); } if ( isObject( arg ) ) { if ( HAS_ITERATOR_SYMBOL === false ) { throw new TypeError( format( 'invalid argument. Environment lacks Symbol.iterator support. Must provide a length, typed array, or array-like object. Value: `%s`.', arg ) ); } if ( !isFunction( arg[ ITERATOR_SYMBOL ] ) ) { throw new TypeError( format( 'invalid argument. Must provide a length, typed array, array-like object, or an iterable. Value: `%s`.', arg ) ); } arg = arg[ ITERATOR_SYMBOL ](); if ( !isFunction( arg.next ) ) { throw new TypeError( format( 'invalid argument. Must provide a length, typed array, array-like object, or an iterable. Value: `%s`.', arg ) ); } return filledArrayIterator( arg, clbk, thisArg ); } throw new TypeError( format( 'invalid argument. Must provide a length, typed array, array-like object, or an iterable. Value: `%s`.', arg ) ); } else if ( isArrayBuffer( arg ) ) { throw new Error( 'invalid arguments. Creating a generic array from an ArrayBuffer is not supported.' ); } throw new TypeError( format( 'invalid argument. Must provide a length, typed array, array-like object, or an iterable. Value: `%s`.', arg ) ); } if ( nargs === 0 ) { // length || array-like || ArrayBuffer || iterable arg = arguments[ 0 ]; if ( isCollection( arg ) ) { arr = new ctor( arg.length ); } else if ( isArrayBuffer( arg ) ) { arr = new ctor( arg ); } else if ( isNonNegativeInteger( arg ) ) { arr = new ctor( arg ); } else if ( isObject( arg ) ) { if ( HAS_ITERATOR_SYMBOL === false ) { throw new TypeError( format( 'invalid argument. Environment lacks Symbol.iterator support. Must provide a length, typed array, or array-like object. Value: `%s`.', arg ) ); } if ( !isFunction( arg[ ITERATOR_SYMBOL ] ) ) { throw new TypeError( format( 'invalid argument. Must provide a length, typed array, array-like object, or an iterable. Value: `%s`.', arg ) ); } arg = arg[ ITERATOR_SYMBOL ](); if ( !isFunction( arg.next ) ) { throw new TypeError( format( 'invalid argument. Must provide a length, typed array, array-like object, or an iterable. Value: `%s`.', arg ) ); } arr = new ctor( iterLength( arg ) ); } else { throw new TypeError( format( 'invalid argument. Must provide a length, typed array, array-like object, or an iterable. Value: `%s`.', arg ) ); } } else if ( nargs === 1 ) { arr = new ctor( arguments[0], arguments[1] ); // (ArrayBuffer, byteOffset) } else { arr = new ctor( arguments[0], arguments[1], arguments[2] ); // (ArrayBuffer, byteOffset, length) } if ( arr.length > 0 ) { if ( isComplexDataType( dtype ) || isBooleanDataType( dtype ) ) { filledAccessors( arr, clbk, thisArg ); } else { gfillBy( arr.length, arr, 1, callback ); } } return arr; /** * Callback which wraps a provided callback and is invoked for each array element. * * @private * @param {*} value - element value * @param {NonNegativeInteger} aidx - array index * @param {NonNegativeInteger} sidx - strided index * @param {Collection} array - input array/collection * @returns {*} callback return value */ function callback( value, aidx ) { return clbk.call( thisArg, aidx ); } } // EXPORTS // module.exports = filledarrayBy;