Design patterns·Functional ideas that went mainstream
you built one function out of three others, and the intermediate values never got names.
Function composition
Also calledcompose, pipe, composing functions
Combining functions so the output of one becomes the input of the next, producing a new function rather than a result. It is pipes and filters at the expression level, and it is why small single-purpose functions are worth more than they look. It requires the pieces to agree on their types, which is exactly the constraint that keeps a composed pipeline honest.