+1 from me I can't count the number of times I've had this bite me when writing ByteString-like APIs that pun names from the Prelude.
On Jul 23, 2012, at 8:28 PM, Lennart Augustsson <lenn...@augustsson.net> wrote: > It's not often that one gets the chance to change something as > fundamental as the scoping rules of a language. Nevertheless, I would > like to propose a change to Haskell's scoping rules. > > The change is quite simple. As it is, top level entities in a module > are in the same scope as all imported entities. I suggest that this > is changed to that the entities from the module are in an inner scope > and do not clash with imported identifiers. > > Why? Consider the following snippet > > module M where > import I > foo = True > > Assume this compiles. Now change the module I so it exports something > called foo. After this change the module M no longer compiles since > (under the current scoping rules) the imported foo clashes with the > foo in M. > > Pros: Module compilation becomes more robust under library changes. > Fewer imports with hiding are necessary. > > Cons: There's the chance that you happen to define a module identifier > with the same name as something imported. This will typically lead to > a type error, but there is a remote chance it could have the same > type. > > Implementation status: The Mu compiler has used the scoping rule for > several years now and it works very well in practice. > > -- Lennart > > _______________________________________________ > Haskell-prime mailing list > Haskell-prime@haskell.org > http://www.haskell.org/mailman/listinfo/haskell-prime _______________________________________________ Haskell-prime mailing list Haskell-prime@haskell.org http://www.haskell.org/mailman/listinfo/haskell-prime
