+
+
+%************************************************************************
+%* *
+\subsection{Getting patterns out of bindings}
+%* *
+%************************************************************************
+
+Get all the pattern type signatures out of a bunch of bindings
+
+\begin{code}
+collectSigTysFromHsBinds :: HsBinds name -> [HsType name]
+collectSigTysFromHsBinds EmptyBinds = []
+collectSigTysFromHsBinds (IPBinds _ _) = []
+collectSigTysFromHsBinds (MonoBind b _ _) = collectSigTysFromMonoBinds b
+collectSigTysFromHsBinds (ThenBinds b1 b2) = collectSigTysFromHsBinds b1 ++
+ collectSigTysFromHsBinds b2
+
+
+collectSigTysFromMonoBinds :: MonoBinds name -> [HsType name]
+collectSigTysFromMonoBinds bind
+ = go bind []
+ where
+ go EmptyMonoBinds acc = acc
+ go (PatMonoBind pat _ loc) acc = collectSigTysFromPat pat ++ acc
+ go (FunMonoBind f _ ms loc) acc = go_matches ms acc
+ go (AndMonoBinds bs1 bs2) acc = go bs1 (go bs2 acc)
+
+ -- A binding like x :: a = f y
+ -- is parsed as FunMonoBind, but for this purpose we
+ -- want to treat it as a pattern binding
+ go_matches [] acc = acc
+ go_matches (Match [] (Just sig) _ : matches) acc = sig : go_matches matches acc
+ go_matches (match : matches) acc = go_matches matches acc
+\end{code}
+
+\begin{code}
+collectStmtsBinders :: [Stmt id] -> [id]
+collectStmtsBinders = concatMap collectStmtBinders
+
+collectStmtBinders :: Stmt id -> [id]
+ -- Id Binders for a Stmt... [but what about pattern-sig type vars]?
+collectStmtBinders (BindStmt pat _ _) = collectPatBinders pat
+collectStmtBinders (LetStmt binds) = collectHsBinders binds
+collectStmtBinders (ExprStmt _ _ _) = []
+collectStmtBinders (ResultStmt _ _) = []
+collectStmtBinders other = panic "collectStmtBinders"
+\end{code}
+