Learning Functional Programming in Go

(g.f)(x) = g(f(x)) composition in Go

This is a graphical representation of our final example of composition in Go:

Don't gloss over that diagram. Study it. Let it sink in.

This is composition, the fundamental principle of functional programming.

That (g.f)(x) = g(f(x)) equation is quite literal. It says that we can execute the f function, Humanize(true), and then pass that value "yes" to g ... Emphasize("yes") to get "yes!!".

That (g.f)(x) = g(f(x)) equation says one more thing. It says that we can nest our functions, g(f(x)), which is like going from A to B and then B to C, or we can simply go directly from A to C by executing EmphasizeHumanize(true) ...