Hi
Of course it's still very easy in the case that it's applied everywhere. You split the string based on ';'. If you get two parts its a normal name, if you get 3 or 4 parts its a class instance. Three is possible because the instance dictionary is generated as
Foo.Bar;Prelude.Eq;Foo.Bar.Baz = (,) Foo.Bar;Prelude.Eq;Foo.Bar.Baz;== Foo.Bar;Prelude.Eq;Foo.Bar.Baz;/=
True, this leads me to the conclusion that in dictionaries we separate all pieces with ; - leaving 3 or 4 pieces. I know you can still split the dictionary, but by the time you've got 4 ;'s floating around, you are a million miles from either Data.Maybe.fromJust or Data.Maybe;fromJust - so I think being consistent with Haskell wins.
Don't you then pay to create a thunk, then evaluate it later? I thought that this was one of the main costs saved by strictness, which wouldn't be saved by a case transformation.
Conceptually, no
case f x of _ -> ...
is a perfectly reasonable description to the backend that 'f x' should be compiled strictly (i.e. without thunks).
Yes, but: foo x y = case x of _ -> ... And in another module: bar x = foo (f x) x Now the (f x) thunk is still created, then immediately forced. If we are expanding our .hi file format (which should only be done once its binary!) we could add some inlining information as well, esp for things like otherwise. Thanks Neil