https://github.com/thisables/curry
:curry: Currying made simple.
https://github.com/thisables/curry
Last synced: about 22 hours ago
JSON representation
:curry: Currying made simple.
- Host: GitHub
- URL: https://github.com/thisables/curry
- Owner: thisables
- License: mit
- Created: 2014-12-31T08:14:47.000Z (almost 11 years ago)
- Default Branch: master
- Last Pushed: 2019-11-07T17:23:59.000Z (about 6 years ago)
- Last Synced: 2025-10-24T19:55:44.821Z (24 days ago)
- Language: JavaScript
- Homepage:
- Size: 109 KB
- Stars: 86
- Watchers: 5
- Forks: 6
- Open Issues: 4
-
Metadata Files:
- Readme: README.md
- License: LICENSE.md
Awesome Lists containing this project
- fucking-awesome-fp-js - curry
- awesome-fp-js - curry
README
[](https://travis-ci.org/stoeffel/curry-this)
[](https://coveralls.io/r/stoeffel/curry-this?branch=master)
[](http://badge.fury.io/js/curry-this)
[](https://david-dm.org/1-liners/1-liners)
[](https://github.com/zenparsing/es-function-bind)
**Currying made simple.**
– and we really mean simple:
```js
import {curry, _} from '@thisables/curry';
// Got a simple function?
const plus = (
(a, b, c) => a + b + c
)::curry();
plus(1, 2, 3); //» 6
plus(1)(2, 3); //» 6
plus(1, 2)(3); //» 6
plus(1)(2)(3); //» 6
// Got a monster function?
const {open} = require('fs');
const newScript = open::curry(_, 'w', 0755, _);
newScript('do-wonders.sh', (error, file) => {
// The `file` is ready.
});
```
Installation
------------
```sh
npm install @thisables/curry
```
Usage
---
### Basic usage
The function `curry` is invoked using the [function bind syntax](https://github.com/zenparsing/es-function-bind) and returns a curried function.
```js
const add = (a, b) => a + b;
const curriedAdd = add::curry();
curriedAdd(1)(2); //» 3
```
### Placeholders
A placeholder `_` is a special value, which you import from `'curry-this'`.
Placeholders are replaced from left to right, the next call after a placeholder is passed replaces the previous placeholders one by one.
```js
const foo = (a, b, c, d) => [a, b, c, d];
const curriedFoo = foo::curry(_, _, _, 4);
curriedFoo(1)(2)(3); //» [1, 2, 3, 4]
```
If you pass a placeholder to `curry` the length of the function is **ignored** instead the initial call of `curry` defines the length of the curried function.
```js
const foo = (...values) => values;
const curriedFoo = foo::curry(_, _, _);
curriedFoo(1)(2)(3); //» [1, 2, 3]
```
### Arity
The curried function has a fixed arity. Additional arguments aren't passed.
```js
const foo = (...values) => values;
const curriedFoo = foo::curry(_, _, _);
curriedFoo(1)(2)(3, 5, 6, 7); //» [1, 2, 3]
```
### Not experimental usage
You can still use `curry` without the experimental syntax
```js
const add = (a, b) => a + b;
const curriedAdd = curry.call(add);
curriedAdd(1)(2); //» 3
```
Or with placeholders
```js
const foo = (...values) => values;
const curriedFoo = curry.call(foo, _, _, _);
curriedFoo(1)(2)(3); //» [1, 2, 3]
```
API
---
### `fn::curry(...args)`
**Parameters**
**fn** | the function to curry
-------|----------------------
**args** | curried arguments or placeholders
**Returns**
A curried function.
`::` huh?
----
If you’re wondering what the `::` thing means, you’d better read this excellent [overview](https://github.com/jussi-kalliokoski/trine/blob/5b735cbfb6b28ae94bac0446d9ecd5ce51fb149b/README.md#why) by [@jussi-kalliokoski](https://github.com/jussi-kalliokoski) or have a look at the [function bind syntax proposal](https://github.com/zenparsing/es-function-bind).
Maintainers
-----------
| [](https://github.com/stoeffel) | [](https://github.com/tomekwi) |
| :--:|:--: |
| [stoeffel](https://github.com/stoeffel) | [tomekwi](https://github.com/tomekwi) |
License
-------
[MIT][] © [Christoph Hermann][]
[MIT]: ./LICENSE.md
[Christoph Hermann]: https://github.com/stoeffel