patch applied (packages/base): IsString is GHC-only (so why is it in the Prelude?)

[Ross Paterson]

Tue Jan 23 10:30:07 PST 2007 Ross Paterson <***@soi.city.ac.uk>
* IsString is GHC-only (so why is it in the Prelude?)

M ./Prelude.hs +2

[Duncan Coutts]

Post by Ross Paterson
* IsString is GHC-only (so why is it in the Prelude?)

Yes, can we please have a discussion about what's going on here.
Changes to the base library are supposed to go via the libraries review
process. I'm not complaining that we slipped up, I just want to make
sure people can have a chance to comment. I'm cc'ing the libraries list.

Duncan

[Malcolm Wallace]

Post by Duncan Coutts

Post by Ross Paterson
* IsString is GHC-only (so why is it in the Prelude?)

Yes, can we please have a discussion about what's going on here.
Changes to the base library are supposed to go via the libraries
review process. I'm not complaining that we slipped up, I just want to
make sure people can have a chance to comment.

I agree that this development is strange. The Prelude module in base is
supposed to export exactly and only the Haskell'98-specified Prelude.
There should be no proposed extensions in there, especially if they are
compiler-specific. There are lots of other places an extension can
live, e.g. GHC.Base

[ Actually, to be honest I'm not quite sure why the Prelude module lives
in the base package, rather than the haskell98 package? The same
question applies to the Numeric module. ]

Regards,
Malcolm

[Simon Marlow]

Post by Malcolm Wallace
[ Actually, to be honest I'm not quite sure why the Prelude module lives
in the base package, rather than the haskell98 package? The same
question applies to the Numeric module. ]

Packages don't support re-exposing modules from other packages right now; it has
been suggested as an extension from time to time. If we did have support for
re-exposing then the haskell98 package could re-expose Prelude and Numeric, and
it would be possible for a pure Haskell 98 program/library to depend only on the
haskell98 package.

Right now we have the situation that a program/library can be independent of the
haskell98 package, which wouldn't be true if Prelude were in haskell98. Also it
would make building base a bit harder, because nothing would be able to import
Prelude.

Cheers,
Simon