parser stuff

lib/Quox/Parser.idr

@@ -87,9 +87,23 @@ find _  _                     = Nothing
 
 
 export
-bound : (what : String) -> Vars k -> Grammar True (Var k)
-bound what vs = terminal "bound \{what} variable" $
-                \case Name x => find1 vs x; _ => Nothing
+checkAvoid1 : Vars n -> String -> Grammar False ()
+checkAvoid1 avoid y =
+  when (isJust $ find1 avoid y) $
+    fail "wrong type of bound variable: \{show y}"
+
+export
+checkAvoid : Vars n -> Name -> Grammar False ()
+checkAvoid avoid (MakeName [<] (UN y)) = checkAvoid1 avoid y
+checkAvoid _     _                     = pure ()
+
+export
+bound : (what : String) -> (bound : Vars k) -> (avoid : Vars n) ->
+        Grammar True (Var k)
+bound what vs avoid = do
+  x <- terminal "bound \{what} variable" $ \case Name x => Just x; _ => Nothing
+  checkAvoid1 avoid x
+  maybe (fail "not in scope: \{x}") pure $ find1 vs x
 
 export
 sname : Grammar True String
@@ -106,24 +120,23 @@ nameWith : (bound : Vars k) -> (avoid : Vars n) ->
            Grammar True (Either (Var k) Name)
 nameWith bound avoid = do
   y <- qname
-  when (isJust $ find avoid y) $
-    fail "wrong type of bound variable: \{show y}"
+  checkAvoid avoid y
   pure $ maybe (Right y) Left $ find bound y
 
 
 export
-dimension : Vars d -> Grammar True (Dim d)
-dimension vs =
+dimension : (dvars : Vars d) -> (tvars : Vars n) -> Grammar True (Dim d)
+dimension dvars tvars =
       K Zero <$  zero
   <|> K One  <$  one
-  <|> B      <$> bound "dimension" vs
+  <|> B      <$> bound "dimension" {bound = dvars, avoid = tvars}
 
 
 mutual
   export
   term : (dvars : Vars d) -> (tvars : Vars n) -> Grammar True (Term d n)
   term dvars tvars =
-        E <$> squares (elim dvars tvars)
+        E <$> squares (elim {dvars, tvars})
 
   export
   elim : (dvars : Vars d) -> (tvars : Vars n) -> Grammar True (Elim d n)