[Haskell-cafe] Reification in Haskell, was: To yi or not to yi

Pasqualino 'Titto' Assini tittoassini at gmail.com
Wed Jun 20 03:30:32 EDT 2007

Hi everybody,

What is the situation with respect to reification of function/thunks in 

Does any current implementation support it ? 

And, is there any plan for GHC to support it?

Claus's comments on this, follow.


On Monday 18 June 2007 23:45:23 Claus Reinke wrote:
> > Is there any fundamental reasons why Haskell functions/closures
> > cannot be serialised?
> no, and that is part of the problem: the language would need to be
> extended, but the academically interesting issues have been tackled,
> all that is left is a lot of work (that is why these things would be so
> valuable: complex implementation machinery, controlled by very
> small language extensions, sometimes even language simplifications,
> such as lifting existing restrictions on i/o), preferably with very good
> planning, so that all the work does not become useless right after it
> is finished. there isn't much hope that this issue is going to be settled
> via the usual academic funding sources.

> > Most languages, even Java, have a reflection capability to dynamically
> > inspect an object. It is surprising that Haskell doesn't offer it.
> it has to be done with care, or it will invalidate *all* your nice
> reasoning about haskell programs. random example
>     reify (f . g) == [| f . g |] =/= [| \x-> f (g x) |] == reify (\x-> f (g
> x))
> reification is not a referentially transparent program context.

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