https://github.com/iplaylf2/facade.ts
A functional style library for TypeScript.
https://github.com/iplaylf2/facade.ts
Last synced: 3 months ago
JSON representation
A functional style library for TypeScript.
- Host: GitHub
- URL: https://github.com/iplaylf2/facade.ts
- Owner: iplaylf2
- License: bsd-3-clause
- Created: 2022-04-04T13:30:04.000Z (about 3 years ago)
- Default Branch: main
- Last Pushed: 2022-04-24T12:28:48.000Z (about 3 years ago)
- Last Synced: 2025-02-15T17:06:23.250Z (3 months ago)
- Language: TypeScript
- Size: 20.5 KB
- Stars: 0
- Watchers: 2
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
# facade.ts
A functional style library for TypeScript.
English | [中文](https://github.com/Iplaylf2/facade.ts/blob/main/doc/README.cn.md)
## install
```bash
npm install facade.ts
```
## usage
```typescript
import { $, $call, compose } from "facade.ts";
const length_of = (x: string) => x.length;
// create a currying function
const greater_than_or_equal = $((a: number, b: number) => a >= b);
// apply partial argument to create a new function
const less_than_5 = greater_than_or_equal(5);
// compose some functions into a new function
const length_less_than_5 = compose(length_of, less_than_5);
// create a currying function for call form, it accept 1 other parameter
const filter = $call(Array.prototype.filter, 1);
// disregard some parameters for now
const filter_by_length = filter($, length_less_than_5);
const filter_by_prop_name = compose(
Object.getOwnPropertyNames,
filter_by_length
);
// same as
// const filter_by_prop_name = function (x: object) {
// return Object.getOwnPropertyNames(x).filter((x) => 5 >= x.length);
// };
console.log(filter_by_prop_name(Array.prototype));
// ['fill', 'find', 'pop', 'push', 'sort', 'join', 'keys', 'flat', 'map', 'some', 'at']
```
## type safe
```typescript
const hello = $(
(name: string, vol: number) => `Hello, ${name}${"!".repeat(vol)}`
);
// console.log(hello("foo")("4"));
// Argument of type '"4"' is not assignable to parameter of type 'number | Placeholder | undefined'.ts(2345)
// hello("foo")(undefined).length
// Property 'length' does not exist on type 'never'.ts(2339)
console.log(hello("foo")(4));
// Hello, foo!!!!
console.log(hello("bar", 1));
// Hello, bar!
```
## api
### $
create a currying function
```typescript
$((a: string) => (b: number) => a.repeat(b)); // Currying<(a: string, b: number) => string>
$((a: string, b: number) => a.repeat(b)); // Currying<(a: string, b: number) => string>
$((a: string, b: number = 1) => a.repeat(b)); // Currying
// the length of parameter should be fixed
$((a: string, b: number = 1) => a.repeat(b), 1); // Currying<(args_0: string) => string>
// add length to the length of parameter
$((a: string, b: number = 1) => a.repeat(b), 2); // Currying<(args_0: string, args_1: number) => string>
```
### $class
create a currying function for constructor
```typescript
const promise = $class(Promise);
```
### $call
create a currying function for call form
```typescript
const reduce = $call(Array.prototype.reduce, 2);
```
### flip
reverse first two arguments' order
```typescript
flip((a: string, b: number) => a.repeat(b));
// same as (b: number , a: string) => a.repeat(b)
```
### compose
perform left-to-right function composition
```typescript
compose(
(a: string) => a.length,
(b: number) => b % 2 === 0,
(c: boolean) => c.toString()
);
// (x :string) => string
```
### margin
wrap a value into a function with any number of parameters
```typescript
margin("foo"); // ()=> string
margin("foo", 2); // (args_0 : any, args_1: any) => string
```
### thrush
take some values and apply a function to them
```typescript
thrush("foo", 3)((a, b) => a.repeat(b)); // foofoofoo
```