On 8/3/07, Isaac Dupree
The surprise is that an unconstrained type-variable being variable rather than instantiated to an arbitrary type, makes any difference (since it doesn't, normally, at runtime).
Right... it's surprising because types aren't supposed to "matter" at runtime.
I would guess the programs `Bool` and `a` are the same once optimizations are turned on? Maybe GHC could avoid the creation of type-lambdas that are unused (in some sense)... with -Onot... I'm dubious about that.
Right, both programs result in the same runtime behavior if optimizations are turned on. (Which, of course, is another surprising thing: the program with the type signature omitted loops if compiled with -Onot and terminates if compiled with -O.) Cheers, Tim -- Tim Chevalier * chevalier@alum.wellesley.edu * Often in error, never in doubt