f-utility/lib/array.js

functional utilities

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.alterLastIndex = exports.alterFirstIndex = exports.alterIndex = exports.__alterIndex = exports.relativeIndex = exports.__relativeIndex = exports.symmetricDifference = exports.__symmetricDifference = exports.difference = exports.__difference = exports.sort = exports.__sort = exports.concat = exports.join = undefined;

var _entrust = require("entrust");

var _katsuCurry = require("katsu-curry");

var _filter = require("./filter");

/**
 * string.prototype.join but curried
 * @method join
 * @param {string} delimiter
 * @param {Array} list
 * @returns {string} joined
 * @public
 * @example
 * import {join} from 'f-utility'
 * join(`x`, [1,2,3]) // `1x2x3`
 */
var join = exports.join = (0, _entrust.e1)("join");

/**
 * return a new array with some other stuff added to it
 * @method concat
 * @param {Array} - an array
 * @param {Array} - another array
 * @returns {Array} - combined array
 */
var concat = exports.concat = (0, _katsuCurry.curry)(function (a, b) {
  return a.concat(b);
});

/**
 * string.prototype.sort but curried
 * @method sort
 * @param {function} fn
 * @param {Array} functor
 * @returns {Array} sorted
 * @public
 * @example
 * import {sort} from 'f-utility'
 * sort((x) => x % 2, [1,2,3,4,5,6,7,8]) // [ 0, 2, 4, 6, 8, 9, 7, 5, 3, 1 ]
 */
// we can't just invert things with entrust, as sort is a mutating method
var __sort = exports.__sort = function __sort(fn, functor) {
  var copy = Array.from(functor);
  copy.sort(fn);
  return copy;
};
// export const sort = e1(`sort`)
var sort = exports.sort = (0, _katsuCurry.curry)(__sort);

/**
 * get the difference between two arrays
 * @method difference
 * @param {Array} bList - an array
 * @param {Array} aList - an array
 * @returns {Array} filtered array with differences between the two arrays
 * @public
 * @example
 * import {difference} from 'f-utility'
 * difference([1,2,3], [2,4,6]) // [4, 6]
 * difference([2,4,6], [1,2,3]) // [1, 3]
 */
var __difference = exports.__difference = function __difference(bList, aList) {
  return (0, _filter.filter)(function (x) {
    return !aList.includes(x);
  }, bList);
};
var difference = exports.difference = (0, _katsuCurry.curry)(__difference);

/**
 * get both the differences between two arrays, and if one difference is longer, return it
 * @method symmetricDifference
 * @param {Array} a - an array
 * @param {Array} b - an array
 * @returns {Array} filtered array with differences between the two arrays
 * @public
 * @example
 * import {symmetricDifference} from 'f-utility'
 * difference([1,2,3], [1,2]) // [3]
 */
var __symmetricDifference = exports.__symmetricDifference = function __symmetricDifference(a, b) {
  var ab = difference(a, b);
  var ba = difference(b, a);
  return ab.concat(ba);
};
var symmetricDifference = exports.symmetricDifference = (0, _katsuCurry.curry)(__symmetricDifference);

/**
 * alter the index of a given array input
 * @method alterIndex
 * @param {number} index - the index to alter
 * @param {Function} fn - the function to describe the alteration
 * @param {Array} input - the input array
 * @returns {Array} an altered copy of the original array
 * @public
 * @example
 * import {alterIndex} from 'f-utility'
 * const input = `abcde`.split(``)
 * alterIndex(0, () => `butts`, input) // [`butts`, `b`, `c`, `d`, `e`]
 * // also works with negative indicies
 * alterIndex(-1, () => `x`, input) // [`a`, `b`, `c`, `d`, `x`]
 */

var __relativeIndex = exports.__relativeIndex = function __relativeIndex(length, index) {
  return index > -1 ? index : length - Math.abs(index);
};

var relativeIndex = exports.relativeIndex = (0, _katsuCurry.curry)(__relativeIndex);

var __alterIndex = exports.__alterIndex = function __alterIndex(index, fn, input) {
  var i = relativeIndex(input.length, index);
  var copy = [].concat(input);
  copy[i] = fn(copy[i]);
  return copy;
};
var alterIndex = exports.alterIndex = (0, _katsuCurry.curry)(__alterIndex);

var alterFirstIndex = exports.alterFirstIndex = alterIndex(0);
var alterLastIndex = exports.alterLastIndex = alterIndex(-1);