I'm trying to support SCCs at the top-level. The implementation should be trivial except the parsing part turned out to be tricky. Since expressions can appear at the top-level, after a {-# SCC ... #-} parser can't decide whether to reduce the token in `sigdecl` to generate a `(LHsDecl (Sig (SCCSig ...)))` or to keep shifting to parse an expression. As shifting is the default behavior when a shift/reduce conflict happens, it's always trying to parse an expression, which is always the wrong thing to do. Does anyone have any ideas on how to handle this? Motivation: Not having SCCs at the top level is becoming annoying real quick. For simplest cases, it's possible to do this transformation: f x y = ... => f = {-# SCC f #-} \x y -> ... However, it doesn't work when there's a `where` clause: f x y = <t is in scope> where t = ... => f = {-# SCC f #-} \x y -> <t is out of scope> where t = ... Or when we have a "equation style" definition: f (C1 ...) = ... f (C2 ...) = ... f (C3 ...) = ... ... (usual solution is to rename `f` to `f'` and define a new `f` with a `SCC`)