On Fri, Aug 17, 2007 at 04:27:29PM -0400, Thomas Hartman wrote:
trying to compile regex-tdfa, I ran into another issue. (earlier I had a cabal problem but that's resolved.)
there's a line that won't compile, neither for ghc 6.6.1 nor 6.7
import GHC.Prim(MutableByteArray#,RealWorld,Int#,sizeofMutableByteArray#,unsafeCoerce#)
so the fresh darcs regex tdfa package won't build.
This line (line 16 below) causes this error for
ghc -e '' RunMutState.hs
for both ghc 6.1 and 6.7
There are at least two things going on here. 1. GHC-specific unboxed identifiers have a # in the name. I think this is a relic from back when the only reasonable way to namespace was to modify your compiler to add extra identifier characters, and use them in all non-portable identifiers. In any case, you have to enable the -fglasgow-exts option (or -XMagicHash in recent 6.7) to allow imports of such identifiers. 2. Explicitly importing GHC.Prim has been discouraged for as long as I can remember, and GHC HQ has finally made good on the promise to make it impossible. Code which imports it has a bug already, which can be fixed by switching to GHC.Exts. (Why? GHC.Prim is wired into the compiler, while GHC.Exts is a normal Haskell module, so by using GHC.Exts you are insulated from questions of what is primitive and what is derived but still unportable. Yes, this does change.) Stefan