Top.Fold.concat elaborates

8 files changed, 129 insertions, 92 deletions

diff --git a/lib/ur/basis.urs b/lib/ur/basis.urs
index cd2468ba..c2a55168 100644
--- a/lib/ur/basis.urs
+++ b/lib/ur/basis.urs
@@ -277,7 +277,7 @@ val sql_current_timestamp : sql_nfunc time
 (*** Executing queries *)
 
 val query : tables ::: {{Type}} -> exps ::: {Type}
-            -> fn [tables ~ exps] =>
+            -> [tables ~ exps] =>
                   state ::: Type
                   -> sql_query tables exps
                   -> ($(exps ++ map (fn fields :: {Type} => $fields) tables)
@@ -298,7 +298,7 @@ val insert : fields ::: {Type}
              -> dml
 
 val update : unchanged ::: {Type} -> changed :: {Type} ->
-             fn [changed ~ unchanged] =>
+             [changed ~ unchanged] =>
                 $(map (fn t :: Type => sql_exp [T = changed ++ unchanged] [] [] t) changed)
                 -> sql_table (changed ++ unchanged)
                 -> sql_exp [T = changed ++ unchanged] [] [] bool
@@ -326,23 +326,23 @@ val tag : attrsGiven ::: {Type} -> attrsAbsent ::: {Type}
           -> ctxOuter ::: {Unit} -> ctxInner ::: {Unit}
           -> useOuter ::: {Type} -> useInner ::: {Type}
           -> bindOuter ::: {Type} -> bindInner ::: {Type}
-          -> fn [attrsGiven ~ attrsAbsent]
-                    [useOuter ~ useInner]
-                    [bindOuter ~ bindInner] =>
-                $attrsGiven
-                -> tag (attrsGiven ++ attrsAbsent)
-                       ctxOuter ctxInner useOuter bindOuter
-                -> xml ctxInner useInner bindInner
-                -> xml ctxOuter (useOuter ++ useInner) (bindOuter ++ bindInner)
+          -> [attrsGiven ~ attrsAbsent] =>
+             [useOuter ~ useInner] =>
+             [bindOuter ~ bindInner] =>
+           $attrsGiven
+           -> tag (attrsGiven ++ attrsAbsent)
+                  ctxOuter ctxInner useOuter bindOuter
+           -> xml ctxInner useInner bindInner
+           -> xml ctxOuter (useOuter ++ useInner) (bindOuter ++ bindInner)
 val join : ctx ::: {Unit} 
         -> use1 ::: {Type} -> bind1 ::: {Type} -> bind2 ::: {Type}
-        -> fn [use1 ~ bind1] [bind1 ~ bind2] =>
+        -> [use1 ~ bind1] => [bind1 ~ bind2] =>
               xml ctx use1 bind1
               -> xml ctx (use1 ++ bind1) bind2
               -> xml ctx use1 (bind1 ++ bind2)
 val useMore : ctx ::: {Unit} -> use1 ::: {Type} -> use2 ::: {Type}
               -> bind ::: {Type}
-              -> fn [use1 ~ use2] =>
+              -> [use1 ~ use2] =>
                     xml ctx use1 bind
                     -> xml ctx (use1 ++ use2) bind
 
@@ -370,11 +370,11 @@ val title : unit -> tag [] head [] [] []
 val body : unit -> tag [] html body [] []
 con bodyTag = fn (attrs :: {Type}) =>
                  ctx ::: {Unit} ->
-                 fn [[Body] ~ ctx] =>
+                 [[Body] ~ ctx] =>
                     unit -> tag attrs ([Body] ++ ctx) ([Body] ++ ctx) [] []
 con bodyTagStandalone = fn (attrs :: {Type}) =>
                            ctx ::: {Unit}
-                           -> fn [[Body] ~ ctx] =>
+                           -> [[Body] ~ ctx] =>
                                  unit -> tag attrs ([Body] ++ ctx) [] [] []
 
 val br : bodyTagStandalone []
@@ -399,12 +399,12 @@ val hr : bodyTag []
 val a : bodyTag [Link = transaction page, Onclick = transaction unit]
 
 val form : ctx ::: {Unit} -> bind ::: {Type}
-            -> fn [[Body] ~ ctx] =>
+            -> [[Body] ~ ctx] =>
                   xml form [] bind
                   -> xml ([Body] ++ ctx) [] []
 con formTag = fn (ty :: Type) (inner :: {Unit}) (attrs :: {Type}) =>
                   ctx ::: {Unit}
-                  -> fn [[Form] ~ ctx] =>
+                  -> [[Form] ~ ctx] =>
                         nm :: Name -> unit
                         -> tag attrs ([Form] ++ ctx) inner [] [nm = ty]
 val textbox : formTag string [] [Value = string, Size = int, Source = source string]
@@ -422,7 +422,7 @@ val select : formTag string select []
 val option : unit -> tag [Value = string, Selected = bool] select [] [] []
 
 val submit : ctx ::: {Unit} -> use ::: {Type}
-             -> fn [[Form] ~ ctx] =>
+             -> [[Form] ~ ctx] =>
                    unit
                    -> tag [Value = string, Action = $use -> transaction page]
                           ([Form] ++ ctx) ([Form] ++ ctx) use []
@@ -431,7 +431,7 @@ val submit : ctx ::: {Unit} -> use ::: {Type}
 
 con cformTag = fn (attrs :: {Type}) =>
                   ctx ::: {Unit}
-                  -> fn [[Body] ~ ctx] =>
+                  -> [[Body] ~ ctx] =>
                         unit -> tag attrs ([Body] ++ ctx) [] [] []
 
 val ctextbox : cformTag [Value = string, Size = int, Source = source string]
@@ -439,13 +439,13 @@ val button : cformTag [Value = string, Onclick = transaction unit]
 
 (*** Tables *)
 
-val tabl : other ::: {Unit} -> fn [other ~ [Body, Table]] =>
+val tabl : other ::: {Unit} -> [other ~ [Body, Table]] =>
                                   unit -> tag [Border = int] ([Body] ++ other) ([Body, Table] ++ other) [] []
-val tr : other ::: {Unit} -> fn [other ~ [Body, Table, Tr]] =>
+val tr : other ::: {Unit} -> [other ~ [Body, Table, Tr]] =>
                                 unit -> tag [] ([Body, Table] ++ other) ([Body, Tr] ++ other) [] []
-val th : other ::: {Unit} -> fn [other ~ [Body, Tr]] =>
+val th : other ::: {Unit} -> [other ~ [Body, Tr]] =>
                                 unit -> tag [] ([Body, Tr] ++ other) ([Body] ++ other) [] []
-val td : other ::: {Unit} -> fn [other ~ [Body, Tr]] =>
+val td : other ::: {Unit} -> [other ~ [Body, Tr]] =>
                                 unit -> tag [] ([Body, Tr] ++ other) ([Body] ++ other) [] []
 
 
diff --git a/lib/ur/top.ur b/lib/ur/top.ur
index 79d30354..0fca0a5b 100644
--- a/lib/ur/top.ur
+++ b/lib/ur/top.ur
@@ -3,32 +3,32 @@
 con folder = K ==> fn r :: {K} =>
                       tf :: ({K} -> Type)
                       -> (nm :: Name -> v :: K -> r :: {K} -> tf r
-                          -> fn [[nm] ~ r] => tf ([nm = v] ++ r))
+                          -> [[nm] ~ r] => tf ([nm = v] ++ r))
                       -> tf [] -> tf r
 
 structure Folder = struct
     fun nil K (tf :: {K} -> Type)
             (f : nm :: Name -> v :: K -> r :: {K} -> tf r
-                 -> fn [[nm] ~ r] => tf ([nm = v] ++ r))
+                 -> [[nm] ~ r] => tf ([nm = v] ++ r))
             (i : tf []) = i
 
     fun cons K (r ::: {K}) (nm :: Name) (v :: K) [[nm] ~ r] (fold : folder r)
              (tf :: {K} -> Type)
              (f : nm :: Name -> v :: K -> r :: {K} -> tf r
-                  -> fn [[nm] ~ r] => tf ([nm = v] ++ r))
-             (i : tf []) = f [nm] [v] [r] (fold [tf] f i)
+                  -> [[nm] ~ r] => tf ([nm = v] ++ r))
+             (i : tf []) = f [nm] [v] [r] (fold [tf] f i) !
 
     fun concat K (r1 ::: {K}) (r2 ::: {K}) [r1 ~ r2]
         (f1 : folder r1) (f2 : folder r2)
         (tf :: {K} -> Type)
         (f : nm :: Name -> v :: K -> r :: {K} -> tf r
-             -> fn [[nm] ~ r] => tf ([nm = v] ++ r))
+             -> [[nm] ~ r] => tf ([nm = v] ++ r))
         (i : tf []) =
-        f1 [fn r1' [r1' ~ r2] => tf (r1' ++ r2)] 0
-           (*(fn (nm :: Name) (v :: K) (r1' :: {K}) (acc : fn [r1' ~ r2] => tf (r1' ++ r2))
+        f1 [fn r1' => [r1' ~ r2] => tf (r1' ++ r2)]
+           (fn (nm :: Name) (v :: K) (r1' :: {K}) (acc : [r1' ~ r2] => tf (r1' ++ r2))
                             [[nm] ~ r1'] [[nm = v] ++ r1' ~ r2] =>
-               f [nm] [v] [r1' ++ r2] acc)
-           (f2 [tf] f i)*)
+               f [nm] [v] [r1' ++ r2] acc !)
+           (fn [[] ~ r2] => f2 [tf] f i) !
 end
 
 
@@ -59,74 +59,74 @@ fun txt (t ::: Type) (ctx ::: {Unit}) (use ::: {Type}) (_ : show t) (v : t) =
 
 fun foldUR (tf :: Type) (tr :: {Unit} -> Type)
            (f : nm :: Name -> rest :: {Unit}
-                -> fn [[nm] ~ rest] =>
+                -> [[nm] ~ rest] =>
                       tf -> tr rest -> tr ([nm] ++ rest))
            (i : tr []) (r ::: {Unit}) (fold : folder r)=
     fold [fn r :: {Unit} => $(mapUT tf r) -> tr r]
          (fn (nm :: Name) (t :: Unit) (rest :: {Unit}) acc
                           [[nm] ~ rest] r =>
-             f [nm] [rest] r.nm (acc (r -- nm)))
+             f [nm] [rest] ! r.nm (acc (r -- nm)))
          (fn _ => i)
 
 fun foldUR2 (tf1 :: Type) (tf2 :: Type) (tr :: {Unit} -> Type)
            (f : nm :: Name -> rest :: {Unit}
-                -> fn [[nm] ~ rest] =>
+                -> [[nm] ~ rest] =>
                       tf1 -> tf2 -> tr rest -> tr ([nm] ++ rest))
            (i : tr []) (r ::: {Unit}) (fold : folder r) =
     fold [fn r :: {Unit} => $(mapUT tf1 r) -> $(mapUT tf2 r) -> tr r]
          (fn (nm :: Name) (t :: Unit) (rest :: {Unit}) acc
                           [[nm] ~ rest] r1 r2 =>
-             f [nm] [rest] r1.nm r2.nm (acc (r1 -- nm) (r2 -- nm)))
+             f [nm] [rest] ! r1.nm r2.nm (acc (r1 -- nm) (r2 -- nm)))
          (fn _ _ => i)
 
 fun foldURX2 (tf1 :: Type) (tf2 :: Type) (ctx :: {Unit})
            (f : nm :: Name -> rest :: {Unit}
-                -> fn [[nm] ~ rest] =>
+                -> [[nm] ~ rest] =>
                       tf1 -> tf2 -> xml ctx [] []) =
     foldUR2 [tf1] [tf2] [fn _ => xml ctx [] []]
             (fn (nm :: Name) (rest :: {Unit}) [[nm] ~ rest] v1 v2 acc =>
-                <xml>{f [nm] [rest] v1 v2}{acc}</xml>)
+                <xml>{f [nm] [rest] ! v1 v2}{acc}</xml>)
             <xml/>
 
 fun foldR K (tf :: K -> Type) (tr :: {K} -> Type)
            (f : nm :: Name -> t :: K -> rest :: {K}
-                -> fn [[nm] ~ rest] =>
+                -> [[nm] ~ rest] =>
                       tf t -> tr rest -> tr ([nm = t] ++ rest))
            (i : tr []) (r ::: {K}) (fold : folder r) =
     fold [fn r :: {K} => $(map tf r) -> tr r]
              (fn (nm :: Name) (t :: K) (rest :: {K}) (acc : _ -> tr rest)
                               [[nm] ~ rest] r =>
-                 f [nm] [t] [rest] r.nm (acc (r -- nm)))
+                 f [nm] [t] [rest] ! r.nm (acc (r -- nm)))
              (fn _ => i)
 
 fun foldR2 K (tf1 :: K -> Type) (tf2 :: K -> Type) (tr :: {K} -> Type)
             (f : nm :: Name -> t :: K -> rest :: {K}
-                 -> fn [[nm] ~ rest] =>
+                 -> [[nm] ~ rest] =>
                        tf1 t -> tf2 t -> tr rest -> tr ([nm = t] ++ rest))
             (i : tr []) (r ::: {K}) (fold : folder r) =
     fold [fn r :: {K} => $(map tf1 r) -> $(map tf2 r) -> tr r]
          (fn (nm :: Name) (t :: K) (rest :: {K})
                           (acc : _ -> _ -> tr rest) [[nm] ~ rest] r1 r2 =>
-             f [nm] [t] [rest] r1.nm r2.nm (acc (r1 -- nm) (r2 -- nm)))
+             f [nm] [t] [rest] ! r1.nm r2.nm (acc (r1 -- nm) (r2 -- nm)))
          (fn _ _ => i)
 
 fun foldRX K (tf :: K -> Type) (ctx :: {Unit})
             (f : nm :: Name -> t :: K -> rest :: {K}
-                 -> fn [[nm] ~ rest] =>
+                 -> [[nm] ~ rest] =>
                        tf t -> xml ctx [] []) =
     foldR [tf] [fn _ => xml ctx [] []]
           (fn (nm :: Name) (t :: K) (rest :: {K}) [[nm] ~ rest] r acc =>
-              <xml>{f [nm] [t] [rest] r}{acc}</xml>)
+              <xml>{f [nm] [t] [rest] ! r}{acc}</xml>)
           <xml/>
 
 fun foldRX2 K (tf1 :: K -> Type) (tf2 :: K -> Type) (ctx :: {Unit})
              (f : nm :: Name -> t :: K -> rest :: {K}
-                  -> fn [[nm] ~ rest] =>
+                  -> [[nm] ~ rest] =>
                         tf1 t -> tf2 t -> xml ctx [] []) =
     foldR2 [tf1] [tf2] [fn _ => xml ctx [] []]
            (fn (nm :: Name) (t :: K) (rest :: {K}) [[nm] ~ rest]
                             r1 r2 acc =>
-               <xml>{f [nm] [t] [rest] r1 r2}{acc}</xml>)
+               <xml>{f [nm] [t] [rest] ! r1 r2}{acc}</xml>)
            <xml/>
 
 fun queryX (tables ::: {{Type}}) (exps ::: {Type}) (ctx ::: {Unit})
@@ -148,13 +148,14 @@ fun queryX' (tables ::: {{Type}}) (exps ::: {Type}) (ctx ::: {Unit})
           <xml/>
 
 fun oneOrNoRows (tables ::: {{Type}}) (exps ::: {Type})
-                (q : sql_query tables exps) [tables ~ exps] =
+                [tables ~ exps]
+                (q : sql_query tables exps)  =
     query q
           (fn fs _ => return (Some fs))
           None
 
 fun oneRow (tables ::: {{Type}}) (exps ::: {Type})
-                (q : sql_query tables exps) [tables ~ exps] =
+                [tables ~ exps] (q : sql_query tables exps) =
     o <- oneOrNoRows q;
     return (case o of
                 None => error <xml>Query returned no rows</xml>
diff --git a/lib/ur/top.urs b/lib/ur/top.urs
index 563f6afd..a32a87a3 100644
--- a/lib/ur/top.urs
+++ b/lib/ur/top.urs
@@ -3,15 +3,15 @@
 con folder = K ==> fn r :: {K} =>
                       tf :: ({K} -> Type)
                       -> (nm :: Name -> v :: K -> r :: {K} -> tf r
-                          -> fn [[nm] ~ r] => tf ([nm = v] ++ r))
+                          -> [[nm] ~ r] => tf ([nm = v] ++ r))
                       -> tf [] -> tf r
 
 structure Folder : sig
     val nil : K --> folder (([]) :: {K})
     val cons : K --> r ::: {K} -> nm :: Name -> v :: K
-               -> fn [[nm] ~ r] => folder r -> folder ([nm = v] ++ r)
+               -> [[nm] ~ r] => folder r -> folder ([nm = v] ++ r)
     val concat : K --> r1 ::: {K} -> r2 ::: {K}
-                 -> fn [r1 ~ r2] => folder r1 -> folder r2 -> folder (r1 ++ r2)
+                 -> [r1 ~ r2] => folder r1 -> folder r2 -> folder (r1 ++ r2)
 end
 
 
@@ -40,78 +40,78 @@ val txt : t ::: Type -> ctx ::: {Unit} -> use ::: {Type} -> show t -> t
 
 val foldUR : tf :: Type -> tr :: ({Unit} -> Type)
              -> (nm :: Name -> rest :: {Unit}
-                 -> fn [[nm] ~ rest] =>
+                 -> [[nm] ~ rest] =>
                        tf -> tr rest -> tr ([nm] ++ rest))
              -> tr [] -> r ::: {Unit} -> folder r -> $(mapUT tf r) -> tr r
 
 val foldUR2 : tf1 :: Type -> tf2 :: Type -> tr :: ({Unit} -> Type)
              -> (nm :: Name -> rest :: {Unit}
-                 -> fn [[nm] ~ rest] =>
+                 -> [[nm] ~ rest] =>
                        tf1 -> tf2 -> tr rest -> tr ([nm] ++ rest))
              -> tr [] -> r ::: {Unit} -> folder r -> $(mapUT tf1 r) -> $(mapUT tf2 r) -> tr r
 
 val foldURX2: tf1 :: Type -> tf2 :: Type -> ctx :: {Unit}
               -> (nm :: Name -> rest :: {Unit}
-                  -> fn [[nm] ~ rest] =>
+                  -> [[nm] ~ rest] =>
                         tf1 -> tf2 -> xml ctx [] [])
               -> r ::: {Unit} -> folder r -> $(mapUT tf1 r) -> $(mapUT tf2 r) -> xml ctx [] []
 
 val foldR : K --> tf :: (K -> Type) -> tr :: ({K} -> Type)
              -> (nm :: Name -> t :: K -> rest :: {K}
-                 -> fn [[nm] ~ rest] =>
+                 -> [[nm] ~ rest] =>
                        tf t -> tr rest -> tr ([nm = t] ++ rest))
              -> tr [] -> r ::: {K} -> folder r -> $(map tf r) -> tr r
 
 val foldR2 : K --> tf1 :: (K -> Type) -> tf2 :: (K -> Type)
              -> tr :: ({K} -> Type)
              -> (nm :: Name -> t :: K -> rest :: {K}
-                 -> fn [[nm] ~ rest] =>
+                 -> [[nm] ~ rest] =>
                        tf1 t -> tf2 t -> tr rest -> tr ([nm = t] ++ rest))
              -> tr []
              -> r ::: {K} -> folder r -> $(map tf1 r) -> $(map tf2 r) -> tr r
 
 val foldRX : K --> tf :: (K -> Type) -> ctx :: {Unit}
              -> (nm :: Name -> t :: K -> rest :: {K}
-                 -> fn [[nm] ~ rest] =>
+                 -> [[nm] ~ rest] =>
                        tf t -> xml ctx [] [])
              -> r ::: {K} -> folder r -> $(map tf r) -> xml ctx [] []
 
 val foldRX2 : K --> tf1 :: (K -> Type) -> tf2 :: (K -> Type) -> ctx :: {Unit}
               -> (nm :: Name -> t :: K -> rest :: {K}
-                  -> fn [[nm] ~ rest] =>
+                  -> [[nm] ~ rest] =>
                         tf1 t -> tf2 t -> xml ctx [] [])
               -> r ::: {K} -> folder r
               -> $(map tf1 r) -> $(map tf2 r) -> xml ctx [] []
 
 val queryX : tables ::: {{Type}} -> exps ::: {Type} -> ctx ::: {Unit}
              -> sql_query tables exps
-             -> fn [tables ~ exps] =>
+             -> [tables ~ exps] =>
                    ($(exps ++ map (fn fields :: {Type} => $fields) tables)
                     -> xml ctx [] [])
                    -> transaction (xml ctx [] [])
 
 val queryX' : tables ::: {{Type}} -> exps ::: {Type} -> ctx ::: {Unit}
               -> sql_query tables exps
-              -> fn [tables ~ exps] =>
+              -> [tables ~ exps] =>
                     ($(exps ++ map (fn fields :: {Type} => $fields) tables)
                      -> transaction (xml ctx [] []))
                     -> transaction (xml ctx [] [])
                        
 val oneOrNoRows : tables ::: {{Type}} -> exps ::: {Type}
-                  -> sql_query tables exps
-                  -> fn [tables ~ exps] =>
-                        transaction
-                            (option
-                                 $(exps
-                                       ++ map (fn fields :: {Type} => $fields) tables))
+                  -> [tables ~ exps] =>
+                  sql_query tables exps
+                  -> transaction
+                         (option
+                              $(exps
+                                    ++ map (fn fields :: {Type} => $fields) tables))
 
 val oneRow : tables ::: {{Type}} -> exps ::: {Type}
-             -> sql_query tables exps
-             -> fn [tables ~ exps] =>
-                   transaction
-                       $(exps
-                             ++ map (fn fields :: {Type} => $fields) tables)
-
+             -> [tables ~ exps] =>
+             sql_query tables exps
+             -> transaction
+                    $(exps
+                          ++ map (fn fields :: {Type} => $fields) tables)
+                
 val eqNullable : tables ::: {{Type}} -> agg ::: {{Type}} -> exps ::: {Type}
                  -> t ::: Type -> sql_injectable (option t)
                  -> sql_exp tables agg exps (option t)
diff --git a/src/elaborate.sml b/src/elaborate.sml
index 6c55626f..201b9150 100644
--- a/src/elaborate.sml
+++ b/src/elaborate.sml
@@ -1025,7 +1025,7 @@
 
  val enD = map Disjoint
 
- fun elabHead env infer (e as (_, loc)) t =
+ fun elabHead (env, denv) infer (e as (_, loc)) t =
      let
          fun unravel (t, e) =
              case hnormCon env t of
@@ -1059,6 +1059,16 @@
                      else
                          (e, t, [])
                  end
+               | (L'.TDisjoint (r1, r2, t'), loc) =>
+                 if infer <> L.TypesOnly then
+                     let
+                         val gs = D.prove env denv (r1, r2, loc)
+                         val (e, t, gs') = unravel (t', e)
+                     in
+                         (e, t, enD gs @ gs')
+                     end
+                 else
+                     (e, t, [])
                | t => (e, t, [])
     in
         case infer of
@@ -1185,7 +1195,7 @@ fun c2s c =
       | Datatype _ => "Datatype"
       | Record _ => "Record"
 
-fun exhaustive (env, t, ps) =
+fun exhaustive (env, t, ps, loc) =
     let
         fun depth (p, _) =
             case p of
@@ -1364,7 +1374,8 @@ fun exhaustive (env, t, ps) =
                         end
                       | L'.CError => true
                       | c =>
-                        (prefaces "Not a datatype" [("c", p_con env (c, ErrorMsg.dummySpan))];
+                        (prefaces "Not a datatype" [("loc", PD.string (ErrorMsg.spanToString loc)),
+                                                    ("c", p_con env (c, ErrorMsg.dummySpan))];
                          raise Fail "isTotal: Not a datatype")
                 end
               | Record _ => List.all (fn c2 => coverageImp (c, c2)) (enumerateCases depth t)
@@ -1437,8 +1448,8 @@ fun elabExp (env, denv) (eAll as (e, loc)) =
                  E.NotBound =>
                  (expError env (UnboundExp (loc, s));
                   (eerror, cerror, []))
-               | E.Rel (n, t) => elabHead env infer (L'.ERel n, loc) t
-               | E.Named (n, t) => elabHead env infer (L'.ENamed n, loc) t)
+               | E.Rel (n, t) => elabHead (env, denv) infer (L'.ERel n, loc) t
+               | E.Named (n, t) => elabHead (env, denv) infer (L'.ENamed n, loc) t)
           | L.EVar (m1 :: ms, s, infer) =>
             (case E.lookupStr env m1 of
                  NONE => (expError env (UnboundStrInExp (loc, m1));
@@ -1457,7 +1468,7 @@ fun elabExp (env, denv) (eAll as (e, loc)) =
                                           cerror)
                                | SOME t => t
                  in
-                     elabHead env infer (L'.EModProj (n, ms, s), loc) t
+                     elabHead (env, denv) infer (L'.EModProj (n, ms, s), loc) t
                  end)
 
           | L.EWild =>
@@ -1566,6 +1577,20 @@ fun elabExp (env, denv) (eAll as (e, loc)) =
 
                 (e', (L'.TDisjoint (c1', c2', t), loc), enD gs1 @ enD gs2 @ gs3)
             end
+          | L.EDisjointApp e =>
+            let
+                val (e', t, gs1) = elabExp (env, denv) e
+
+                val k1 = kunif loc
+                val c1 = cunif (loc, (L'.KRecord k1, loc))
+                val k2 = kunif loc
+                val c2 = cunif (loc, (L'.KRecord k2, loc))
+                val t' = cunif (loc, ktype)
+                val () = checkCon env e' t (L'.TDisjoint (c1, c2, t'), loc)
+                val gs2 = D.prove env denv (c1, c2, loc)
+            in
+                (e', t', enD gs2 @ gs1)
+            end
 
           | L.ERecord xes =>
             let
@@ -1617,11 +1642,10 @@ fun elabExp (env, denv) (eAll as (e, loc)) =
                 val ft = cunif (loc, ktype)
                 val rest = cunif (loc, ktype_record)
                 val first = (L'.CRecord (ktype, [(c', ft)]), loc)
-                            
+                val () = checkCon env e' et
+                                  (L'.TRecord (L'.CConcat (first, rest), loc), loc);
                 val gs3 = D.prove env denv (first, rest, loc)
             in
-                checkCon env e' et
-                         (L'.TRecord (L'.CConcat (first, rest), loc), loc);
                 ((L'.EField (e', c', {field = ft, rest = rest}), loc), ft, gs1 @ enD gs2 @ enD gs3)
             end
 
@@ -1633,10 +1657,11 @@ fun elabExp (env, denv) (eAll as (e, loc)) =
                 val r1 = cunif (loc, ktype_record)
                 val r2 = cunif (loc, ktype_record)
 
+                val () = checkCon env e1' e1t (L'.TRecord r1, loc)
+                val () = checkCon env e2' e2t (L'.TRecord r2, loc)
+
                 val gs3 = D.prove env denv (r1, r2, loc)
             in
-                checkCon env e1' e1t (L'.TRecord r1, loc);
-                checkCon env e2' e2t (L'.TRecord r2, loc);
                 ((L'.EConcat (e1', r1, e2', r2), loc),
                  (L'.TRecord ((L'.CConcat (r1, r2), loc)), loc),
                  gs1 @ gs2 @ enD gs3)
@@ -1649,11 +1674,12 @@ fun elabExp (env, denv) (eAll as (e, loc)) =
                 val ft = cunif (loc, ktype)
                 val rest = cunif (loc, ktype_record)
                 val first = (L'.CRecord (ktype, [(c', ft)]), loc)
+
+                val () = checkCon env e' et
+                                  (L'.TRecord (L'.CConcat (first, rest), loc), loc)
                             
                 val gs3 = D.prove env denv (first, rest, loc)
             in
-                checkCon env e' et
-                         (L'.TRecord (L'.CConcat (first, rest), loc), loc);
                 ((L'.ECut (e', c', {field = ft, rest = rest}), loc), (L'.TRecord rest, loc),
                  gs1 @ enD gs2 @ enD gs3)
             end
@@ -1663,11 +1689,12 @@ fun elabExp (env, denv) (eAll as (e, loc)) =
                 val (c', ck, gs2) = elabCon (env, denv) c
 
                 val rest = cunif (loc, ktype_record)
+
+                val () = checkCon env e' et
+                                  (L'.TRecord (L'.CConcat (c', rest), loc), loc)
                             
                 val gs3 = D.prove env denv (c', rest, loc)
             in
-                checkCon env e' et
-                         (L'.TRecord (L'.CConcat (c', rest), loc), loc);
                 ((L'.ECutMulti (e', c', {rest = rest}), loc), (L'.TRecord rest, loc),
                  gs1 @ enD gs2 @ enD gs3)
             end
@@ -1681,15 +1708,15 @@ fun elabExp (env, denv) (eAll as (e, loc)) =
                                      let
                                          val ((p', pt), (env, _)) = elabPat (p, (env, SS.empty))
 
-                                         val (e', et, gs1) = elabExp (env, denv) e
+                                         val (e', et', gs1) = elabExp (env, denv) e
                                      in
                                          checkPatCon env p' pt et;
-                                         checkCon env e' et result;
+                                         checkCon env e' et' result;
                                          ((p', e'), gs1 @ gs)
                                      end)
                                  gs1 pes
             in
-                if exhaustive (env, et, map #1 pes') then
+                if exhaustive (env, et, map #1 pes', loc) then
                     ()
                 else
                     expError env (Inexhaustive loc);
@@ -1722,10 +1749,11 @@ and elabEdecl denv (dAll as (d, loc), (env, gs)) =
 
                     val (e', et, gs2) = elabExp (env, denv) e
 
+                    val () = checkCon env e' et c'
+
                     val c' = normClassConstraint env c'
                     val env' = E.pushERel env x c'
                 in
-                    checkCon env e' et c';
                     ((L'.EDVal (x, c', e'), loc), (env', enD gs1 @ gs2 @ gs))
                 end
               | L.EDValRec vis =>
@@ -2958,10 +2986,12 @@ fun elabDecl (dAll as (d, loc), (env, denv, gs)) =
                                          | SOME c => elabCon (env, denv) c
 
                     val (e', et, gs2) = elabExp (env, denv) e
+
+                    val () = checkCon env e' et c'
+
                     val c = normClassConstraint env c'
                     val (env', n) = E.pushENamed env x c'
                 in
-                    checkCon env e' et c';
                     (*prefaces "DVal" [("x", Print.PD.string x),
                                      ("c'", p_con env c')];*)
                     ([(L'.DVal (x, n, c', e'), loc)], (env', denv, enD gs1 @ gs2 @ gs))
diff --git a/src/source.sml b/src/source.sml
index 6c117777..9ef14fd9 100644
--- a/src/source.sml
+++ b/src/source.sml
@@ -124,6 +124,7 @@ datatype exp' =
        | ECApp of exp * con
        | ECAbs of explicitness * string * kind * exp
        | EDisjoint of con * con * exp
+       | EDisjointApp of exp
 
        | EKAbs of string * exp
 
diff --git a/src/source_print.sml b/src/source_print.sml
index 4453454d..8d8b28c3 100644
--- a/src/source_print.sml
+++ b/src/source_print.sml
@@ -267,6 +267,9 @@ fun p_exp' par (e, _) =
                                                    string "=>",
                                                    space,
                                                    p_exp e])
+      | EDisjointApp e => parenIf par (box [p_exp e,
+                                            space,
+                                            string "!"])
 
       | ERecord xes => box [string "{",
                             p_list (fn (x, e) =>
diff --git a/src/urweb.grm b/src/urweb.grm
index 86e8a5df..43c9947a 100644
--- a/src/urweb.grm
+++ b/src/urweb.grm
@@ -187,7 +187,7 @@ fun tagIn bt =
  | CON | LTYPE | VAL | REC | AND | FUN | MAP | UNIT | KUNIT | CLASS
  | DATATYPE | OF
  | TYPE | NAME
- | ARROW | LARROW | DARROW | STAR | SEMI | KARROW | DKARROW
+ | ARROW | LARROW | DARROW | STAR | SEMI | KARROW | DKARROW | BANG
  | FN | PLUSPLUS | MINUSMINUS | MINUSMINUSMINUS | DOLLAR | TWIDDLE
  | LET | IN
  | STRUCTURE | SIGNATURE | STRUCT | SIG | END | FUNCTOR | WHERE | EXTERN | SQL
@@ -710,6 +710,7 @@ ident  : CSYMBOL                        (CName CSYMBOL, s (CSYMBOLleft, CSYMBOLr
 eapps  : eterm                          (eterm)
        | eapps eterm                    (EApp (eapps, eterm), s (eappsleft, etermright))
        | eapps LBRACK cexp RBRACK       (ECApp (eapps, cexp), s (eappsleft, RBRACKright))
+       | eapps BANG                     (EDisjointApp eapps, s (eappsleft, BANGright))
 
 eexp   : eapps                          (eapps)
        | FN eargs DARROW eexp           (let
diff --git a/src/urweb.lex b/src/urweb.lex
index bb57f03d..cbbf2a52 100644
--- a/src/urweb.lex
+++ b/src/urweb.lex
@@ -276,6 +276,7 @@ notags = [^<{\n]+;
 <INITIAL> "*"         => (Tokens.STAR (pos yypos, pos yypos + size yytext));
 <INITIAL> "<-"        => (Tokens.LARROW (pos yypos, pos yypos + size yytext));
 <INITIAL> ";"         => (Tokens.SEMI (pos yypos, pos yypos + size yytext));
+<INITIAL> "!"         => (Tokens.BANG (pos yypos, pos yypos + size yytext));
 
 <INITIAL> "+"         => (Tokens.PLUS (pos yypos, pos yypos + size yytext));
 <INITIAL> "-"         => (Tokens.MINUS (pos yypos, pos yypos + size yytext));