Keean Schupke wrote:
If a function is exported it cannot be inlined, can it? When I edit a module I generally don't have to recompile my whole program even if I compile with -O2... After all the fuss about certain type class extensions breaking separate compilation it would be a bit odd if it was broken already?
Again: Haskell is not C. Exported functions are exported including their implementation if GHC thinks that "they are worth it". What this exactly means can be tuned by a few parameters. A simple example: --------------------------------------------------------------------------- module Foo where bar :: Bool -> Int bar False = 123 bar True = 456 --------------------------------------------------------------------------- panne@jeanluc:~> ghc -O2 -c Foo.hs panne@jeanluc:~> ghc --show-iface Foo.hi interface "Main" Foo 1 6030 where export Foo bar module dependencies: package dependencies: base orphans: Foreign.C.Types Foreign.Ptr GHC.Base GHC.Float GHC.Int GHC.List GHC.Word bar :: GHC.Base.Bool -> GHC.Base.Int {- Arity: 1 HasNoCafRefs Strictness: Sm Unfolding: (\ ds :: GHC.Base.Bool -> case @ GHC.Base.Int ds of wild { False -> lvl1 True -> lvl }) -} lvl :: GHC.Base.Int {- HasNoCafRefs Strictness: m Unfolding: (GHC.Base.I# 456) -} lvl1 :: GHC.Base.Int {- HasNoCafRefs Strictness: m Unfolding: (GHC.Base.I# 123) -} --------------------------------------------------------------------------- You can see that every little detail is exported here. This is extremely important for good performance and I happily trade separate compilation (in the traditional sense) for this. Note that 'ghc --make' easily handles the recompilation issue for your own programs. Libraries where you want some kind of binary backwards compatibility are another story. Here you have to trade (just like C!) efficiency against flexibility, e.g. by writing some kind of facade compiled without -O. Cheers, S.