curry

TypeScript-first curry function without upcast

A curly function with a strict type definition. There is no upcast to any types, respecting the typedef of the callback function.

✨ Features

• ⚡ Multi runtime support (Deno, Node.js and Browsers)
• 📚 Pure TypeScript and provides type definition
• 🌎 Universal module, providing ES modules and Commonjs
• 📦 Optimized, super slim size
• 📄 TSDoc-style comments

Package name

Deno: curry (deno.land, nest.land)

Node.js: curry-rice (npm)

The origin of the word curry-rice is Rice and curry 🍛.

⚡ Overview

ReturnValue

const replace = (from: string, to: string, val: string) =>
  val.replace(from, to);
const curriedReplace = curry(replace);

curriedReplace("hello", "hi", "hello world"); // 'hi world'
curriedReplace("hello")("hi", "hello world"); // 'hi world'
curriedReplace("hello", "hi")("hello world"); // 'hi world'
curriedReplace("hello")("hi")("hello world"); // 'hi world'
curriedReplace("hello", "hi", "hello world"); // 'hi world'

ReturnType

curriedReplace("hello"); // (to: string, val: string): string

curriedReplace("hello")("hi"); // (val: string): string
curriedReplace("hello", "hi"); // (val: string): string

curriedReplace("hello", "hi", "hello world"); // string
curriedReplace("hello")("hi")("hello world"); // string
curriedReplace("hello", "hi")("hello world"); // string
curriedReplace("hello")("hi", "hello world"); // string

💫 Usage

curry provides multi platform modules.

🦕 Deno

deno.land

import { curry } from "https://deno.land/x/curry/mod.ts";

curry(AnyFn);

nest.land

import { curry } from "https://x.nest.land/curry/mod.ts";

curry(AnyFn);

📦 Node.js

NPM package name is curry-rice .

Install

npm i curry-rice
or
yarn add curry-rice

ES modules

import { curry } from "curry-rice";

curry(AnyFn);

Commonjs

const { curry } = require("curry-rice");

curry(AnyFn);

🌐 Browser

The module that bundles the dependencies is obtained from skypack.

<script type="module">
  import { curry } from "https://cdn.skypack.dev/curry-rice";
  curry(AnyFn)
</script>

API

Type definition

curry

declare const curry: <T extends unknown[], R>(
  fn: (...args: T) => R,
) => Curried<T, R>;

=> The new curried function

Example

const nullary = () => true;
curry(nullary); // ()  => boolean
const unary = (val: number) => val++;
curry(unary); // (val: number)  => number
const binaryFn = (a: number, b: number) => a + b;
curry(binaryFn); // (a: number, b: number)  => number || (a: number) => (b:number) => number

Restriction

This package is focused on getting correct type inference. Hence, there are the following limitations:

• Maximum number of arity is 19.

Beyond that, the type system will breaks.

• Overloads function cannot be correctly type inferred.

Overloads function is something like this:

function len(s: string): number;
function len(arr: any[]): number;
function len(x: any) {
  return x.length;
}

For example, it has the following differences from lodash.curry.

• lodash.curry has a placeholder feature, which this package does not have.
• The argument of the curried function in lodash.curry is any types, but in this package, the type of the original argument is inferred.

Although placeholders are a useful feature, it is very difficult to implement it while maintaining correct type inference.

If you can solve this issue, please make a pull request.

💚 Supports

ie is no longer supported to reduce bundle size.

The TypeScript version must be 4.1.0 or higher.

This project provides ES modules and Commonjs.

If you have an opinion about what to support, you can open an issue to discuss it.

The browserslist has the following settings.

defaults
last 8 version
not IE <= 11
not ie_mob <= 11
node 6

Deno	Node.js	Edge	Firefox	Chrome	Safari	iOS Safari	Samsung	Opera
^1.6.0	^6.17.0	^83	^78	^83	^11	^12.0	^7.2	^68

🤝 Contributing

Contributions, issues and feature requests are welcome!
Feel free to check issues.

Contributing guide

🌱 Show your support

Give a ⭐️ if this project helped you!

💡 License

Copyright © 2021-present TomokiMiyauci.

Released under the MIT license