ramda.partialright
Version:
R.partialRight exported as a module
270 lines (254 loc) • 8.57 kB
JavaScript
// Ramda v0.26.1
// https://github.com/ramda/ramda
// (c) 2013-2019 Scott Sauyet, Michael Hurley, and David Chambers
// Ramda may be freely distributed under the MIT license.
(function (global, factory) {
typeof exports === 'object' && typeof module !== 'undefined' ? factory(exports) :
typeof define === 'function' && define.amd ? define(['exports'], factory) :
(factory((global.R = {})));
}(this, (function (exports) { 'use strict';
/**
* Private `concat` function to merge two array-like objects.
*
* @private
* @param {Array|Arguments} [set1=[]] An array-like object.
* @param {Array|Arguments} [set2=[]] An array-like object.
* @return {Array} A new, merged array.
* @example
*
* _concat([4, 5, 6], [1, 2, 3]); //=> [4, 5, 6, 1, 2, 3]
*/
function _concat(set1, set2) {
set1 = set1 || [];
set2 = set2 || [];
var idx;
var len1 = set1.length;
var len2 = set2.length;
var result = [];
idx = 0;
while (idx < len1) {
result[result.length] = set1[idx];
idx += 1;
}
idx = 0;
while (idx < len2) {
result[result.length] = set2[idx];
idx += 1;
}
return result;
}
function _arity(n, fn) {
/* eslint-disable no-unused-vars */
switch (n) {
case 0: return function() { return fn.apply(this, arguments); };
case 1: return function(a0) { return fn.apply(this, arguments); };
case 2: return function(a0, a1) { return fn.apply(this, arguments); };
case 3: return function(a0, a1, a2) { return fn.apply(this, arguments); };
case 4: return function(a0, a1, a2, a3) { return fn.apply(this, arguments); };
case 5: return function(a0, a1, a2, a3, a4) { return fn.apply(this, arguments); };
case 6: return function(a0, a1, a2, a3, a4, a5) { return fn.apply(this, arguments); };
case 7: return function(a0, a1, a2, a3, a4, a5, a6) { return fn.apply(this, arguments); };
case 8: return function(a0, a1, a2, a3, a4, a5, a6, a7) { return fn.apply(this, arguments); };
case 9: return function(a0, a1, a2, a3, a4, a5, a6, a7, a8) { return fn.apply(this, arguments); };
case 10: return function(a0, a1, a2, a3, a4, a5, a6, a7, a8, a9) { return fn.apply(this, arguments); };
default: throw new Error('First argument to _arity must be a non-negative integer no greater than ten');
}
}
function _isPlaceholder(a) {
return a != null &&
typeof a === 'object' &&
a['@@functional/placeholder'] === true;
}
/**
* Optimized internal one-arity curry function.
*
* @private
* @category Function
* @param {Function} fn The function to curry.
* @return {Function} The curried function.
*/
function _curry1(fn) {
return function f1(a) {
if (arguments.length === 0 || _isPlaceholder(a)) {
return f1;
} else {
return fn.apply(this, arguments);
}
};
}
/**
* Optimized internal two-arity curry function.
*
* @private
* @category Function
* @param {Function} fn The function to curry.
* @return {Function} The curried function.
*/
function _curry2(fn) {
return function f2(a, b) {
switch (arguments.length) {
case 0:
return f2;
case 1:
return _isPlaceholder(a)
? f2
: _curry1(function(_b) { return fn(a, _b); });
default:
return _isPlaceholder(a) && _isPlaceholder(b)
? f2
: _isPlaceholder(a)
? _curry1(function(_a) { return fn(_a, b); })
: _isPlaceholder(b)
? _curry1(function(_b) { return fn(a, _b); })
: fn(a, b);
}
};
}
function _createPartialApplicator(concat) {
return _curry2(function(fn, args) {
return _arity(Math.max(0, fn.length - args.length), function() {
return fn.apply(this, concat(args, arguments));
});
});
}
/**
* Internal curryN function.
*
* @private
* @category Function
* @param {Number} length The arity of the curried function.
* @param {Array} received An array of arguments received thus far.
* @param {Function} fn The function to curry.
* @return {Function} The curried function.
*/
function _curryN(length, received, fn) {
return function() {
var combined = [];
var argsIdx = 0;
var left = length;
var combinedIdx = 0;
while (combinedIdx < received.length || argsIdx < arguments.length) {
var result;
if (combinedIdx < received.length &&
(!_isPlaceholder(received[combinedIdx]) ||
argsIdx >= arguments.length)) {
result = received[combinedIdx];
} else {
result = arguments[argsIdx];
argsIdx += 1;
}
combined[combinedIdx] = result;
if (!_isPlaceholder(result)) {
left -= 1;
}
combinedIdx += 1;
}
return left <= 0
? fn.apply(this, combined)
: _arity(left, _curryN(length, combined, fn));
};
}
/**
* Returns a curried equivalent of the provided function, with the specified
* arity. The curried function has two unusual capabilities. First, its
* arguments needn't be provided one at a time. If `g` is `R.curryN(3, f)`, the
* following are equivalent:
*
* - `g(1)(2)(3)`
* - `g(1)(2, 3)`
* - `g(1, 2)(3)`
* - `g(1, 2, 3)`
*
* Secondly, the special placeholder value [`R.__`](#__) may be used to specify
* "gaps", allowing partial application of any combination of arguments,
* regardless of their positions. If `g` is as above and `_` is [`R.__`](#__),
* the following are equivalent:
*
* - `g(1, 2, 3)`
* - `g(_, 2, 3)(1)`
* - `g(_, _, 3)(1)(2)`
* - `g(_, _, 3)(1, 2)`
* - `g(_, 2)(1)(3)`
* - `g(_, 2)(1, 3)`
* - `g(_, 2)(_, 3)(1)`
*
* @func
* @memberOf R
* @since v0.5.0
* @category Function
* @sig Number -> (* -> a) -> (* -> a)
* @param {Number} length The arity for the returned function.
* @param {Function} fn The function to curry.
* @return {Function} A new, curried function.
* @see R.curry
* @example
*
* const sumArgs = (...args) => R.sum(args);
*
* const curriedAddFourNumbers = R.curryN(4, sumArgs);
* const f = curriedAddFourNumbers(1, 2);
* const g = f(3);
* g(4); //=> 10
*/
var curryN = _curry2(function curryN(length, fn) {
if (length === 1) {
return _curry1(fn);
}
return _arity(length, _curryN(length, [], fn));
});
/**
* Returns a new function much like the supplied one, except that the first two
* arguments' order is reversed.
*
* @func
* @memberOf R
* @since v0.1.0
* @category Function
* @sig ((a, b, c, ...) -> z) -> (b -> a -> c -> ... -> z)
* @param {Function} fn The function to invoke with its first two parameters reversed.
* @return {*} The result of invoking `fn` with its first two parameters' order reversed.
* @example
*
* const mergeThree = (a, b, c) => [].concat(a, b, c);
*
* mergeThree(1, 2, 3); //=> [1, 2, 3]
*
* R.flip(mergeThree)(1, 2, 3); //=> [2, 1, 3]
* @symb R.flip(f)(a, b, c) = f(b, a, c)
*/
var flip = _curry1(function flip(fn) {
return curryN(fn.length, function(a, b) {
var args = Array.prototype.slice.call(arguments, 0);
args[0] = b;
args[1] = a;
return fn.apply(this, args);
});
});
/**
* Takes a function `f` and a list of arguments, and returns a function `g`.
* When applied, `g` returns the result of applying `f` to the arguments
* provided to `g` followed by the arguments provided initially.
*
* @func
* @memberOf R
* @since v0.10.0
* @category Function
* @sig ((a, b, c, ..., n) -> x) -> [d, e, f, ..., n] -> ((a, b, c, ...) -> x)
* @param {Function} f
* @param {Array} args
* @return {Function}
* @see R.partial
* @example
*
* const greet = (salutation, title, firstName, lastName) =>
* salutation + ', ' + title + ' ' + firstName + ' ' + lastName + '!';
*
* const greetMsJaneJones = R.partialRight(greet, ['Ms.', 'Jane', 'Jones']);
*
* greetMsJaneJones('Hello'); //=> 'Hello, Ms. Jane Jones!'
* @symb R.partialRight(f, [a, b])(c, d) = f(c, d, a, b)
*/
var partialRight = _createPartialApplicator(flip(_concat));
exports.partialRight = partialRight;
Object.defineProperty(exports, '__esModule', { value: true });
})));