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Maybe/Option Monad

Represents a value which may or may not exist. Semantically, operations continue on a Just, and do not execute on a None.

Construction

This type has two public constructors which are Just and None which take 1 argument and 0 arguments respectively.

However, there is also a semi-intelligent constructor on the Maybe itself, which will coerce based on existence of value. Any value that is undefined or null is a None and everything else is a Just.

var s = require("singularity").monad,
    myJust = s.Maybe.from(5),
    myNone = s.Maybe.from(undefined),
    printer = s.Maybe
        .destructure()
        .Just(function (x) { console.log(x); })
        .None(function () {});

printer(myJust); // prints 5
printer(myNone); // nothing prints

It is possible to do s.Just.from(undefined), but for semantic reasons, this is discouraged unless this is really the behavior you are looking for.