[Haskell-cafe] Can someone explain this typing restriction?
Gerrit van den Geest
G.vandenGeest at students.uu.nl
Mon Aug 14 10:40:05 EDT 2006
Gerrit van den Geest wrote:
>> I had a feeling this was discussed in "Typing Haskell in Haskell" by
>> Mark Jones, but after a quick skim I can't find it again (I thought
>> it would be
>> in Section 11.6 of his paper).
> It is, on page 35 (section 11.6.3) of "Typing Haskell in Haskell" by
> Mark Jones.
"This is a consequence of a throw-away comment specifying that all
explicit type signatures in a binding group must have the same context
up to renaming of variables. This is a syntactic restriction that can
easily be checked prior to type checking. Our comment here, however,
suggest that it is unnecessarily restrictive."
I agree with Mark Jones, the Haskell compiler Helium for example doesn't
have this restriction.
I think this issue is also related to the following Haskell' ticket:
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