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Diffstat (limited to 'node_modules/async/map.js')
-rw-r--r-- | node_modules/async/map.js | 142 |
1 files changed, 142 insertions, 0 deletions
diff --git a/node_modules/async/map.js b/node_modules/async/map.js new file mode 100644 index 0000000..ec4135d --- /dev/null +++ b/node_modules/async/map.js @@ -0,0 +1,142 @@ +'use strict'; + +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'];
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