[Haskell-cafe] Re: Data constructors versus types

[Achim Schneider]

Peter Verswyvelen <bf3 at telenet.be> wrote:

> I know nothing about theoretical computer science, but I was wondering
> if it possible to forget about types, and just keep the concept of
> data constructors, and have an analyzer determine correctness of the
> code and "staticness" of the data?
> 
> Basically this is what SCHEME does no? Doesn't SCHEME have static
> whole program analyzers to remove the overhead of the "symbol tags"
> and check correctness of a program (Stalin, Petit-Scheme, ...)?
> 
> What are to pros/contras?
> 
Basically, it's a matter of taste, and how much of the checking can be
done at compile-time... which gets quite involved and O(big), if all
you have is (tagged) lists with type information.

And, yes, Stalin manages to specialize a -> a functions to Int -> Int
to make numerical code as fast or faster than C, but so does GHC.

Plus a GHC build may allow you to get a coffee, Stalin allows you to go
shopping, watch a movie and then go on vacation.

That is because, in general, you can't forget about the type of your
data, you need it in some way or the other to do anything with it.

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