[Haskell-cafe] Haskell Questions

Daniel Fischer daniel.is.fischer at web.de
Thu Apr 21 14:24:55 EDT 2005


Am Donnerstag, 21. April 2005 20:00 schrieben Sie:
> Daniel,
> Thanks for your offer to help me.
>
> There was a site with some challenges on extending Thompsons code, and the
> first question they asked was the following:
>
> ------------------------------------------------------
> Extend matchType so that it becomes capable of parsing polymorphic types
> like Either a b.
>
> Hint. Define a new type, VarName,
> capable of representing variables, like a, b and entry, as well as its
> associated parser matchVarName.
>
> You might want to Add a new constructor, PolyT, to the definition of Type
> to represent polymorphic types, and define its associated parser
> matchPolyT. Adjust any other functions that definitely need adjusting
> ------------------------------------------------------
>
> I hope this helps you understand what Im trying to achieve more clearly.
>
> Regards
> Mike Richards

Partly. The Problem now is, I don't know what this refers to. No 'matchType' 
etc. appear in my copy of Thompson's book - maybe it's been added after I 
bought mine. 

I suppose, part of the exercise is parsing type signatures, right?

To be of real assistance, I'd need to know what's given, so URL or direct text 
would be great.

Daniel



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