f-utility/lib/path.js

functional utilities

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.propEq = exports.__propEq = exports.propIs = exports.__propIs = exports.pathEq = exports.__pathEq = exports.prop = exports.propOr = exports.__propOr = exports.path = exports.propSatisfies = exports.__propSatisfies = exports.pathSatisfies = exports.__pathSatisfies = exports.pathOr = exports.__pathOr = undefined;

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

var _reduce = require("./reduce");

var _math = require("./math");

/**
 * Grab a nested value from an object or return a default
 * @method pathOr
 * @param {any} def - a default value
 * @param {string[]} lenses - a list of nested properties
 * @param {any} input - an object to grab things from
 * @returns {any} a nested value or default
 * @example
 * import {pathOr} from 'f-utility'
 * pathOr(`default`, [`a`, `b`, `c`], {a: {b: {c: `actual`}}}) // `actual`
 * pathOr(`default`, [`a`, `b`, `c`], {x: {y: {z: `actual`}}}) // `default`
 */
var __pathOr = exports.__pathOr = function __pathOr(def, lenses, input) {
  return (0, _reduce.reduce)(function (focus, lens) {
    return focus[lens] || def;
  }, input, lenses);
};
var pathOr = exports.pathOr = (0, _katsuCurry.curry)(__pathOr);

/**
 * Grab a property from an object and compare it with a given function
 * @method pathSatisfies
 * @param {function} equiv - a test function
 * @param {string} pathTo - a nested property
 * @param {any} input - an object to grab things from
 * @returns {boolean} a truthy value
 */
var __pathSatisfies = exports.__pathSatisfies = function __pathSatisfies(equiv, pathTo, input) {
  return (0, _katsuCurry.pipe)(path(pathTo), equiv, Boolean)(input);
};
var pathSatisfies = exports.pathSatisfies = (0, _katsuCurry.curry)(__pathSatisfies);

/**
 * Grab a property from an object and compare it with a given function
 * @method propSatisfies
 * @param {function} equiv - a test function
 * @param {string} propTo - a nested property
 * @param {any} input - an object to grab things from
 * @returns {boolean} a truthy value
 */
var __propSatisfies = exports.__propSatisfies = function __propSatisfies(equiv, propTo, input) {
  return (0, _katsuCurry.pipe)(prop(propTo), equiv, Boolean)(input);
};
var propSatisfies = exports.propSatisfies = (0, _katsuCurry.curry)(__propSatisfies);

/**
 * Grab a nested value from an object
 * @method path
 * @param {string[]} lenses - a list of nested properties
 * @param {any} input - an object to grab things from
 * @returns {any} a nested value or null
 * @example
 * import {path} from 'f-utility'
 * pathOr([`a`, `b`, `c`], {a: {b: {c: `actual`}}}) // `actual`
 * pathOr([`a`, `b`, `c`], {x: {y: {z: `actual`}}}) // null
 */
var path = exports.path = pathOr(null);

/**
 * Grab a property from an object or return a default
 * @method propOr
 * @param {any} def - a default value
 * @param {string} property - a property
 * @param {any} input - an object to grab things from
 * @returns {any} a property or default
 * @example
 * import {propOr} from 'f-utility'
 * pathOr(`default`, `c`, {c: `actual`}) // `actual`
 * pathOr(`default`, `c`, {z: `actual`}) // `default`
 */
var __propOr = exports.__propOr = function __propOr(def, property, input) {
  return pathOr(def, [property], input);
};
var propOr = exports.propOr = (0, _katsuCurry.curry)(__propOr);

/**
 * Grab a property from an object or return null
 * @method prop
 * @param {string} property - a property
 * @param {any} input - an object to grab things from
 * @returns {any} a property or null
 * @example
 * import {prop} from 'f-utility'
 * path(`c`, {c: `actual`}) // `actual`
 * path(`c`, {z: `actual`}) // null
 */
var prop = exports.prop = propOr(null);

/**
 * Grab a property from an object and compare it with a given value via ===
 * @method pathEq
 * @param {strings[]} lenses - a property
 * @param {any} equiv - equivalent value
 * @param {any} input - an object to grab things from
 * @returns {boolean} a truthy value
 */
var __pathEq = exports.__pathEq = function __pathEq(lenses, equiv, input) {
  return pathSatisfies((0, _math.equals)(equiv), lenses, input);
};
var pathEq = exports.pathEq = (0, _katsuCurry.curry)(__pathEq);

var __propIs = exports.__propIs = function __propIs(type, property, input) {
  return (0, _katsuCurry.pipe)(prop(property), function (val) {
    return val != null && val.constructor === type || val instanceof type;
  }, Boolean)(input);
};
var propIs = exports.propIs = (0, _katsuCurry.curry)(__propIs);

/**
 * Grab a property from an object and compare it with a given value via ===
 * @method propEq
 * @param {string} property - a property
 * @param {any} equiv - equivalent value
 * @param {any} input - an object to grab things from
 * @returns {boolean} a truthy value
 */
var __propEq = exports.__propEq = function __propEq(property, equiv, input) {
  return pathSatisfies((0, _math.equals)(equiv), [property], input);
};
var propEq = exports.propEq = (0, _katsuCurry.curry)(__propEq);