• simonpj@microsoft.com's avatar
    Keep track of explicit kinding in HsTyVarBndr; plus fix Trac #3845 · 836b1e90
    simonpj@microsoft.com authored
    To print HsTypes correctly we should remember whether the Kind on
    a HsTyVarBndr came from type inference, or was put there by the
    user.  See Note [Printing KindedTyVars] in HsTypes.  So instead of
    changing a UserTyVar to a KindedTyVar during kind checking, we
    simply add a PostTcKind to the UserTyVar.
    
    The change was provoked by Trac #3830, although other changes
    mean that #3830 gets a diferent and better error message now.
    So this patch is simply doing the Right Thing for the future.
    
    This patch also fixes Trac #3845, which was caused by a *type splice*
    not remembering the free *term variables* mentioned in it.  Result
    was that we build a 'let' when it should have been 'letrec'.
    Hence a new FreeVars field in HsSpliceTy.
    
    While I was at it, I got rid of HsSpliceTyOut and use a PostTcKind
    on HsSpliceTy instead, just like on the UserTyVar.
    836b1e90
HsDecls.lhs 36.6 KB