darcs patch: make Alex only occupy {alex,Alex,ALEX}* names (still assuming Prelude)

Duncan Coutts duncan.coutts at worc.ox.ac.uk
Thu Jan 17 17:42:01 EST 2008


On Thu, 2008-01-17 at 09:41 -0500, Isaac Dupree wrote:

> Therefore I propose that, though it may break code in the short term, 
> Happy and Alex should only import things qualified as AlexSomething.  It 
> didn't make things too ugly; they still rely on sufficient basic Prelude 
> stuff being imported without qualification by the module that uses 
> Happy/Alex, but that seems the best arrangement to me anyway. (for 
> example, if a module wants to redefine (&&) in a compatible way -- this 
> has been done with type-classes, Alex will at least try to use that 
> instead of importing (&&) unqualified from the Prelude and getting an 
> ambiguity error)
> 
> This patch does that for Alex, and I've been using it to compile GHC; a 
> similar patch would be a similar amount of work to make for Happy.
> 
> Thoughts? Does this seem like a good idea?

Sounds sensible to me.

I've had code break by changing -agc options to happy because it started
importing Haskell98 modules and my package did not depend on the
haskell98 package.

Duncan



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