-- | let' x = e in e'
letE :: VarId -> Exp -> Exp -> Exp
letE x e e' = Case e [Alt noLoc (Just $ litIntE 1) (PVar x) e']
letE :: VarId -> Exp -> Exp -> Exp
letE x e e' = Case e [Alt noLoc (Just $ litIntE 1) (PVar x) e']
letE x e e' = Case e [Alt noLoc (Just $ litIntE 1) (PVar x) e']