Skip to Content
Learning TypeScript 2.x - Second Edition
book

Learning TypeScript 2.x - Second Edition

by Remo H. Jansen
April 2018
Beginner content levelBeginner
536 pages
13h 21m
English
Packt Publishing
Content preview from Learning TypeScript 2.x - Second Edition

Pipes

A pipe is a function or operator that allows us to pass the output of a function as the input of another. JavaScript and TypeScript don't support piles natively (as an operator), but we can implement our pipes using the following function:

const pipe = <T>(...fns: Array<(arg: T) => T>) =>
    (value: T) => fns.reduce((acc, fn) => fn(acc), value); 

We are going to use the curry3, trim, capitalize, and replace functions that we declared previously in this chapter:

const trim = (s: string) => s.trim(); 
const capitalize = (s: string) => s.toUpperCase(); 
 
const replace = curry3( 
    (s: string, f: string, r: string) => s.split(f).join(r) 
); 

We can then use the pipe function to declare a new function:

const trimCapitalizeAndReplace = pipe( trim, ...
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.
Start your free trial

You might also like

Mastering TypeScript - Fourth Edition

Mastering TypeScript - Fourth Edition

Nathan Rozentals
Learning TypeScript

Learning TypeScript

Josh Goldberg
TypeScript for Beginners

TypeScript for Beginners

Bharath Thippireddy

Publisher Resources

ISBN: 9781788391474Supplemental Content