Split map out.

This commit is contained in:
John-David Dalton
2017-04-15 23:22:49 -05:00
parent 73ce6066f8
commit 0bdc73195f
4 changed files with 43 additions and 66 deletions

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@@ -1,20 +0,0 @@
/**
* A specialized version of `map` for arrays.
*
* @private
* @param {Array} [array] The array to iterate over.
* @param {Function} iteratee The function invoked per iteration.
* @returns {Array} Returns the new mapped array.
*/
function arrayMap(array, iteratee) {
let index = -1
const length = array == null ? 0 : array.length
const result = new Array(length)
while (++index < length) {
result[index] = iteratee(array[index], index, array)
}
return result
}
export default arrayMap

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@@ -1,22 +0,0 @@
import baseEach from './baseEach.js'
import isArrayLike from '../isArrayLike.js'
/**
* The base implementation of `map`.
*
* @private
* @param {Array|Object} collection The collection to iterate over.
* @param {Function} iteratee The function invoked per iteration.
* @returns {Array} Returns the new mapped array.
*/
function baseMap(collection, iteratee) {
let index = -1
const result = isArrayLike(collection) ? new Array(collection.length) : []
baseEach(collection, (value, key, collection) => {
result[++index] = iteratee(value, key, collection)
})
return result
}
export default baseMap

38
map.js
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@@ -1,23 +1,10 @@
import arrayMap from './.internal/arrayMap.js'
import baseMap from './.internal/baseMap.js'
/**
* Creates an array of values by running each element in `collection` thru
* `iteratee`. The iteratee is invoked with three arguments:
* (value, index|key, collection).
* Creates an array of values by running each element of `array` thru `iteratee`.
* The iteratee is invoked with three arguments: (value, index, array).
*
* Many lodash methods are guarded to work as iteratees for methods like
* `every`, `filter`, `map`, `mapValues`, `reject`, and `some`.
*
* The guarded methods are:
* `ary`, `chunk`, `curry`, `curryRight`, `drop`, `dropRight`, `every`,
* `fill`, `invert`, `parseInt`, `random`, `range`, `rangeRight`, `repeat`,
* `sampleSize`, `slice`, `some`, `sortBy`, `split`, `take`, `takeRight`,
* `template`, `trim`, `trimEnd`, `trimStart`, and `words`
*
* @since 0.1.0
* @category Collection
* @param {Array|Object} collection The collection to iterate over.
* @since 5.0.0
* @category Array
* @param {Array} array The array to iterate over.
* @param {Function} iteratee The function invoked per iteration.
* @returns {Array} Returns the new mapped array.
* @example
@@ -28,13 +15,16 @@ import baseMap from './.internal/baseMap.js'
*
* map([4, 8], square)
* // => [16, 64]
*
* map({ 'a': 4, 'b': 8 }, square)
* // => [16, 64] (iteration order is not guaranteed)
*/
function map(collection, iteratee) {
const func = Array.isArray(collection) ? arrayMap : baseMap
return func(collection, iteratee)
function map(array, iteratee) {
let index = -1
const length = array == null ? 0 : array.length
const result = new Array(length)
while (++index < length) {
result[index] = iteratee(array[index], index, array)
}
return result
}
export default map

29
mapObject.js Normal file
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@@ -0,0 +1,29 @@
/**
* Creates an array of values by running each property of `object` thru
* `iteratee`. The iteratee is invoked with three arguments: (value, key, object).
*
* @since 5.0.0
* @category Object
* @param {Object} object The object to iterate over.
* @param {Function} iteratee The function invoked per iteration.
* @returns {Array} Returns the new mapped array.
* @example
*
* function square(n) {
* return n * n
* }
*
* map({ 'a': 4, 'b': 8 }, square)
* // => [16, 64] (iteration order is not guaranteed)
*/
function mapObject(object, iteratee) {
const props = Object.keys(object);
const result = new Array(props.length)
props.forEach((key, index) => {
result[index] = iteratee(object[key], key, object)
})
return result
}
export default mapObject