factory.js (3114B)
1 /** 2 * @license Apache-2.0 3 * 4 * Copyright (c) 2018 The Stdlib Authors. 5 * 6 * Licensed under the Apache License, Version 2.0 (the "License"); 7 * you may not use this file except in compliance with the License. 8 * You may obtain a copy of the License at 9 * 10 * http://www.apache.org/licenses/LICENSE-2.0 11 * 12 * Unless required by applicable law or agreed to in writing, software 13 * distributed under the License is distributed on an "AS IS" BASIS, 14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 15 * See the License for the specific language governing permissions and 16 * limitations under the License. 17 */ 18 19 'use strict'; 20 21 // MODULES // 22 23 var copy = require( '@stdlib/utils/copy' ); 24 var RandomStream = require( './main.js' ); 25 26 27 // MAIN // 28 29 /** 30 * Returns a function for creating readable streams which generate pseudorandom numbers drawn from a standard normal distribution. 31 * 32 * @param {Options} [options] - stream options 33 * @param {boolean} [options.objectMode=false] - specifies whether a stream should operate in object mode 34 * @param {(string|null)} [options.encoding=null] - specifies how `Buffer` objects should be decoded to `strings` 35 * @param {NonNegativeNumber} [options.highWaterMark] - specifies the maximum number of bytes to store in an internal buffer before ceasing to generate additional pseudorandom numbers 36 * @param {string} [options.sep='\n'] - separator used to join streamed data 37 * @param {NonNegativeInteger} [options.iter] - number of iterations 38 * @param {string} [options.name='improved-ziggurat'] - name of a supported pseudorandom number generator (PRNG), which will serve as the underlying source of pseudorandom numbers 39 * @param {PRNG} [options.prng] - pseudorandom number generator which generates uniformly distributed pseudorandom numbers 40 * @param {PRNGSeedMT19937} [options.seed] - pseudorandom number generator seed 41 * @param {PRNGStateMT19937} [options.state] - pseudorandom number generator state 42 * @param {boolean} [options.copy=true] - boolean indicating whether to copy a provided pseudorandom number generator state 43 * @param {PositiveInteger} [options.siter] - number of iterations after which to emit the PRNG state 44 * @returns {Function} stream factory 45 * 46 * @example 47 * var opts = { 48 * 'sep': ',', 49 * 'objectMode': false, 50 * 'encoding': 'utf8', 51 * 'highWaterMark': 64 52 * }; 53 * 54 * var createStream = factory( opts ); 55 * 56 * // Create 10 identically configured streams... 57 * var streams = []; 58 * var i; 59 * for ( i = 0; i < 10; i++ ) { 60 * streams.push( createStream() ); 61 * } 62 */ 63 function factory( options ) { 64 var opts; 65 if ( arguments.length > 0 ) { 66 opts = copy( options, 1 ); 67 } else { 68 opts = {}; 69 } 70 return createStream; 71 72 /** 73 * Returns a readable stream for generating pseudorandom numbers drawn from a standard normal distribution. 74 * 75 * @private 76 * @throws {TypeError} options argument must be an object 77 * @throws {TypeError} must provide valid options 78 * @throws {Error} must provide a valid state 79 * @returns {RandomStream} Stream instance 80 */ 81 function createStream() { 82 return new RandomStream( opts ); 83 } 84 } 85 86 87 // EXPORTS // 88 89 module.exports = factory;