Why is the use of Maybe/Option not so pervasive in Clojure?

Question

Why does Clojure, despite such an emphasis on functional paradigm, not use the Maybe/ Option monad to represent optional values? The use of O

Answer 1

It is important to remember that the Monad concept is not about types! Type systems help you enforce the rules (but even Haskell cannot enforce all of the rules, since some of them (the Monad Laws) are cannot be fully expressed by a type system.

Monads are about composition, which is a very important thing that we all do every day in every programming language. In all cases, the Monad tracks some "extra context" about what is going on...think of it like a box that holds onto the current value. Functions can be applied to this value, and the extra context can evolve as an orthogonal concern.

The Maybe type is about chaining long sequences of computation together while not having to say anything at all about failure (which is the "extra context"). It is a pattern that moves the "error handling" out of the computation and into the Monad. You can string a sequence of computations on a Maybe and as soon as one fails, the rest are ignored and the final result is "nothing". If they all succeed, then your final result is the monad holding the result value.

This allows you to write code that is much less entangled.

Clojure supports Monads, as @deterb pointed out.