pipe-and-compose-types

Introduction

This package strictly contains types. The star of this package is a recursive Pipe type with surprising utility over parameter overloading. These benefits include

• parameter name preservation
• theoritically unlimited functions can be composed (recursive)
• variadic input for both Pipe and Compose
• friendly messages on error, pointing to the problem

It's biggest weakness is still stronger than the parameter overloading approach, namely generics on compose functions are not preserved; however, it will accept them and the resulting type will be {}. The overloading approach can actually often fail to compile in those situations.

The main benefit of the overloading approach to this recursive type is that when error occur, the compiler is better able to explain where the error occurred. With this type, in the event of a compile error, the returned type will itself contain information on what went wrong.

Exports

Main

Key exported types include

• Pipe as mentioned above
• Compose data flows from bottom up ( or left to right )
• PipeFn Pipe applied to create a reference function type
• ComposeFn Compose applied to create a reference function type
• PipelineFn Pipe applied to create a useful pipeline function type

Secondary

Other types exported

• ExtractFunctionArguments extracts function arguments
• ExtractFunctionReturnValue extracts a functions return type

Circumstantial

Ad-hoc types that may aid in constructing applications from these types.

• AnyFunction a type representing any kind of function, an alternative to Function
• AnyFunction1 a function representing any function with an arity of 1

Installation

npm install pipe-and-compose-types

Usage

Example:

import { PipeFn } from 'pipe-and-compose-types'

declare const example: ( first: number, rest: number[] ) => number
declare const pipe: PipeFn

const result = pipe(
  example,
  String
) // (first: number, rest: number[]) => string

Read more at https://dev.to/babak/introducing-the-recursive-pipe-and-compose-types-3g9o