Dear Simon, other ghc devs, I hooked into genericHscRecompile to traverse the typechecked source and construct an environment of type [(SrcSpan, Id)] recording all identifiers in the source with their type, definition site, etc. To be precise, I am traversing the tcg_binds :: LHsBinds Id, -- Value bindings in this module field of the TcGblEnv structure returned by the type checker. The problem is that I have so far been unable to find top-level user-supplied type annotations inside LHsBinds. The closest thing I've found is the PostTcType of a MatchGroup, but that is not Located; what I'm really looking for is an LSig. Now, let-bindings get a HsValBindsLR instead of an LHsBinds, and that *does* contain signatures. My question is two-fold: 1. First, am I missing something? Are there LSigs somewhere inside the TcGblEnv where I simply haven't seen them? 2. If not, is there a good reason why tcg_binds is an LHsBinds rather than an HsValBindsLR? And if there isn't, would you accept a patch making the change? Thanks, Edsko