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> In a language that lacks maybes, but has nulls, what is the equivalent of the type Maybe (Maybe Int)? int **
> Even ignoring the lack of composability, flatMap is an operation on a broad category of which Maybe is one example; that generality is a key part of its utility.While it's certainly part of it, I would disagree that it's the key part. The ?. operator is flatMap in the context of Maybes, and Maybes alone are useful for preventing a class of bug (NullPointerExceptions) even without the rest of Monadkind. > ?. is a special-case operation on nullables, if you want to use it on any of the other things that flatMap works on (e.g., lists), you need a different operation, so you can't build generic algorithms. Being able to use generic algorithms like sort() on Maybes-as-collections-of-arity-[0,1], while very cute, isn't actually that useful in real code. Particularly real C# or Java code. Don't get me wrong, I've written code in Scala, and I love the generality of Maybe and related collection types, even though I have hit some interesting issues where I've needed to call .toSeq on my Maybe in order to get the right thing to happen, because they're not quite equivalent. But being pragmatic, and given that C# (and Java) don't have proper Monadic Maybe, and are unlikely to ever get them, I'd quite like the ?. and ?? operators, please. |