; | |
Object.defineProperty(exports, "__esModule", { | |
value: true | |
}); | |
var _map2 = require('./internal/map.js'); | |
var _map3 = _interopRequireDefault(_map2); | |
var _eachOf = require('./eachOf.js'); | |
var _eachOf2 = _interopRequireDefault(_eachOf); | |
var _awaitify = require('./internal/awaitify.js'); | |
var _awaitify2 = _interopRequireDefault(_awaitify); | |
function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; } | |
/** | |
* Produces a new collection of values by mapping each value in `coll` through | |
* the `iteratee` function. The `iteratee` is called with an item from `coll` | |
* and a callback for when it has finished processing. Each of these callbacks | |
* takes 2 arguments: an `error`, and the transformed item from `coll`. If | |
* `iteratee` passes an error to its callback, the main `callback` (for the | |
* `map` function) is immediately called with the error. | |
* | |
* Note, that since this function applies the `iteratee` to each item in | |
* parallel, there is no guarantee that the `iteratee` functions will complete | |
* in order. However, the results array will be in the same order as the | |
* original `coll`. | |
* | |
* If `map` is passed an Object, the results will be an Array. The results | |
* will roughly be in the order of the original Objects' keys (but this can | |
* vary across JavaScript engines). | |
* | |
* @name map | |
* @static | |
* @memberOf module:Collections | |
* @method | |
* @category Collection | |
* @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over. | |
* @param {AsyncFunction} iteratee - An async function to apply to each item in | |
* `coll`. | |
* The iteratee should complete with the transformed item. | |
* Invoked with (item, callback). | |
* @param {Function} [callback] - A callback which is called when all `iteratee` | |
* functions have finished, or an error occurs. Results is an Array of the | |
* transformed items from the `coll`. Invoked with (err, results). | |
* @returns {Promise} a promise, if no callback is passed | |
* @example | |
* | |
* // file1.txt is a file that is 1000 bytes in size | |
* // file2.txt is a file that is 2000 bytes in size | |
* // file3.txt is a file that is 3000 bytes in size | |
* // file4.txt does not exist | |
* | |
* const fileList = ['file1.txt','file2.txt','file3.txt']; | |
* const withMissingFileList = ['file1.txt','file2.txt','file4.txt']; | |
* | |
* // asynchronous function that returns the file size in bytes | |
* function getFileSizeInBytes(file, callback) { | |
* fs.stat(file, function(err, stat) { | |
* if (err) { | |
* return callback(err); | |
* } | |
* callback(null, stat.size); | |
* }); | |
* } | |
* | |
* // Using callbacks | |
* async.map(fileList, getFileSizeInBytes, function(err, results) { | |
* if (err) { | |
* console.log(err); | |
* } else { | |
* console.log(results); | |
* // results is now an array of the file size in bytes for each file, e.g. | |
* // [ 1000, 2000, 3000] | |
* } | |
* }); | |
* | |
* // Error Handling | |
* async.map(withMissingFileList, getFileSizeInBytes, function(err, results) { | |
* if (err) { | |
* console.log(err); | |
* // [ Error: ENOENT: no such file or directory ] | |
* } else { | |
* console.log(results); | |
* } | |
* }); | |
* | |
* // Using Promises | |
* async.map(fileList, getFileSizeInBytes) | |
* .then( results => { | |
* console.log(results); | |
* // results is now an array of the file size in bytes for each file, e.g. | |
* // [ 1000, 2000, 3000] | |
* }).catch( err => { | |
* console.log(err); | |
* }); | |
* | |
* // Error Handling | |
* async.map(withMissingFileList, getFileSizeInBytes) | |
* .then( results => { | |
* console.log(results); | |
* }).catch( err => { | |
* console.log(err); | |
* // [ Error: ENOENT: no such file or directory ] | |
* }); | |
* | |
* // Using async/await | |
* async () => { | |
* try { | |
* let results = await async.map(fileList, getFileSizeInBytes); | |
* console.log(results); | |
* // results is now an array of the file size in bytes for each file, e.g. | |
* // [ 1000, 2000, 3000] | |
* } | |
* catch (err) { | |
* console.log(err); | |
* } | |
* } | |
* | |
* // Error Handling | |
* async () => { | |
* try { | |
* let results = await async.map(withMissingFileList, getFileSizeInBytes); | |
* console.log(results); | |
* } | |
* catch (err) { | |
* console.log(err); | |
* // [ Error: ENOENT: no such file or directory ] | |
* } | |
* } | |
* | |
*/ | |
function map(coll, iteratee, callback) { | |
return (0, _map3.default)(_eachOf2.default, coll, iteratee, callback); | |
} | |
exports.default = (0, _awaitify2.default)(map, 3); | |
module.exports = exports.default; |