Why Maybe Is Better Than Null

Re:Why Maybe Is Better Than Null by cantankerous on Friday April 19, 2013 @01:28PM (#5577742)

The problem isn't just NULL in C. This post is talking about the entire Null/Nil reference problem across all languages that use a null-type value.

This is especially a problem in dynamic languages that sling nils around....like any major modern scripting language. Checking if a value is nil before proceeding is aping what a language like Haskell does when it pattern matches against Maybe (Just a, Nothing) albeit in a post-facto bad way. Granted, you can't really make any assertions about reflecting a maybe value in the type of a language that doesn't care about types before runtime.

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Re:Why Maybe Is Better Than Null by yew on Friday April 19, 2013 @01:59PM (#5577875)

That's the main problem with calling Maybe 'better'. If you don't have static type checking then either you implement it just for Maybe or you end up with the same sorts of problems as you had before.

Making types non-Nullable by default is nice, though. Even in a dynamic language you can have a syntactic distinction to make interfaces more explicit.

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Re:Why Maybe Is Better Than Null by cantankerous on Friday April 19, 2013 @02:58PM (#5578148)

True. I think it's also a covert argument for static type checking, though ;-).

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Re:Why Maybe Is Better Than Null by yew on Friday April 19, 2013 @03:28PM (#5578289)

Give me a statically typed Python and a type system that can handle external hardware poking around in its memory and I'm in ;)

I'm sort of a fan of Haskell already, to tell you the truth.

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Re:Why Maybe Is Better Than Null by dllthomas on Friday April 19, 2013 @04:37PM (#5578587)

> Give me a statically typed Python

Not sure that's so far from Haskell, really... :-P

> and a type system that can handle external hardware poking around in its memory

Can it be in isolated places? That's doable...

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Re:Why Maybe Is Better Than Null by yew on Friday April 19, 2013 @05:14PM (#5578740)

Not sure that's so far from Haskell, really... :-P

Maybe it's my lack of experience talking. Haskell feels heavier in a lot of places. I think the focus on compilation in the backend is almost a downside here, too.

Can it be in isolated places? That's doable...

Depends on the application. There's a lot of hardware out there that does really weird stuff. There's some interesting work in Haskell-space (eg Atom) but I don't know how comprehensively mature it is.

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Re:Why Maybe Is Better Than Null by merijnv on Saturday April 20, 2013 @07:35AM (#5581057)

I actually started designing statically typed Python, since it seemed a fun exercise. Halfway in I realised I was effectively redesigning Haskell with slightly different syntax and stopped.

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