Press n or j to go to the next uncovered block, b, p or k for the previous block.
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 | 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x | /**
* @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 isFunction = require( '@stdlib/assert/is-function' );
var format = require( '@stdlib/string/format' );
var PINF = require( '@stdlib/constants/float64/pinf' );
var validate = require( './validate.js' );
var limit = require( './limit.js' );
// MAIN //
/**
* Returns a function to map keys from one object to a new object having the same values.
*
* ## Notes
*
* - If a provided function calls the provided callback with a truthy error argument, the function suspends execution and immediately calls the `done` callback for subsequent error handling.
* - This function does **not** guarantee that execution is asynchronous. To do so, wrap the `done` callback in a function which either executes at the end of the current stack (e.g., `nextTick`) or during a subsequent turn of the event loop (e.g., `setImmediate`, `setTimeout`).
* - Iteration and insertion order are **not** guaranteed.
* - The function only operates on own properties, not inherited properties.
*
* @param {Options} [options] - function options
* @param {*} [options.thisArg] - execution context
* @param {PositiveInteger} [options.limit] - maximum number of pending invocations at any one time
* @param {boolean} [options.series=false] - boolean indicating whether to wait for a previous invocation to complete before invoking a provided function for the next own property
* @param {Function} transform - transform function
* @throws {TypeError} options argument must be an object
* @throws {TypeError} must provide valid options
* @throws {TypeError} last argument must be a function
* @returns {Function} function which maps keys from one object to a new object having the same values
*
* @example
* var readFile = require( '@stdlib/fs/read-file' );
*
* function read( key, value, next ) {
* var opts = {
* 'encoding': 'utf8'
* };
* readFile( value, opts, onFile );
*
* function onFile( error ) {
* if ( error ) {
* return next( null, key+':unreadable' );
* }
* next( null, key+':readable' );
* }
* }
*
* var opts = {
* 'series': true
* };
*
* // Create a reusable function:
* var mapKeysAsync = factory( opts, read );
*
* // Create a dictionary of file names:
* var files = {
* 'file1': './beep.js',
* 'file2': './boop.js'
* };
*
* // Define a callback which handles errors:
* function done( error, out ) {
* if ( error ) {
* throw error;
* }
* console.log( out );
* }
*
* // Process each file in `files`:
* mapKeysAsync( files, done );
*/
function factory( options, transform ) {
var opts;
var err;
var f;
opts = {};
if ( arguments.length > 1 ) {
err = validate( opts, options );
if ( err ) {
throw err;
}
f = transform;
} else {
f = options;
}
if ( !isFunction( f ) ) {
throw new TypeError( format( 'invalid argument. Last argument must be a function. Value: `%s`.', f ) );
}
if ( opts.series ) {
opts.limit = 1;
} else if ( !opts.limit ) {
opts.limit = PINF;
}
return mapKeysAsync;
/**
* Maps keys from one object to a new object having the same values.
*
* @private
* @param {Object} obj - source object
* @param {Callback} done - function to invoke upon completion
* @throws {TypeError} first argument must be an object
* @throws {TypeError} last argument must be a function
* @returns {void}
*/
function mapKeysAsync( obj, done ) {
if ( typeof obj !== 'object' || obj === null ) {
throw new TypeError( format( 'invalid argument. First argument must be an object. Value: `%s`.', obj ) );
}
if ( !isFunction( done ) ) {
throw new TypeError( format( 'invalid argument. Last argument must be a function. Value: `%s`.', done ) );
}
return limit( obj, opts, f, clbk );
/**
* Callback invoked upon completion.
*
* @private
* @param {*} [error] - error
* @param {Object} [out] - output object
* @returns {void}
*/
function clbk( error, out ) {
if ( error ) {
return done( error );
}
done( null, out );
}
}
}
// EXPORTS //
module.exports = factory;
|