[project @ 2003-01-24 14:04:40 by simonmar]
- Generalise seq to allow an unlifted type in its second argument. This works because seq is *always* inlined and replaced by a case. - Remove getTag, a wired-in Id with an unfolding, with a definition in GHC.Base: getTag x = x `seq` dataToTag# x this is why we required the above generalisation to seq (dataToTag# returns an Int#). See the comments in GHC.Base for more details. - As a side-effect, this fixes a bug in the interpreter, where the compiler optimised away the evaluation of the argument to dataToTag#, but the interpreter ended up passing it an unevaluated thunk (nullary constructors aren't always evaluated in GHCi, but the simplifier assumes they are). Now, in the interpreter, getTag won't be inlined so the compiler can't optimise away the evaluation, and we're saved. The real bug here is either (a) dataToTag# requires an evaluated argument or (b) the interpreter doesn't supply it with one, take your pick.