What is Ramda?

Ramda.js is a JS library of helper functions that have some cool principles baked into every function:

• never mutate the user's data
• always provide the same output given the same input
• allow users to build new functions from old ones by not supplying all of a function's parameters

These ideas — regardless of what library or even language we use — allow us to write safe, extendable code, and the ideas are explored further in the Core Ramda Ideas section that starts with the "Same Input → Same Output" chapter.