basic_rg: we improved the error reporting interface

[helm.git] / helm / software / lambda-delta / basic_rg / brgType.ml

diff --git a/helm/software/lambda-delta/basic_rg/brgType.ml b/helm/software/lambda-delta/basic_rg/brgType.ml
index bf067864714dea8c3127c2b4c07bdccd1b75b451..96c9cb52ab01051f91ac7ac868816504be339eda 100644 (file)
--- a/helm/software/lambda-delta/basic_rg/brgType.ml
+++ b/helm/software/lambda-delta/basic_rg/brgType.ml
@@ -20,83 +20,116 @@ module E = BrgEnvironment
 module S = BrgSubstitution
 module R = BrgReduction
 
+exception TypeError of R.message
+
 (* Internal functions *******************************************************)
 
 let level = 4
 
+let message1 st1 m t1 =
+   L.ct_items1 "In the context" m st1 t1
+
 let log1 s m t =
    let s =  s ^ " the term" in
-   L.log O.specs level (R.message1 s m t) 
+   L.log R.specs level (message1 s m t) 
 
 let error1 s m t =
-   raise (R.TypeError (R.message1 s m t))
+   raise (TypeError (message1 s m t))
 
-(* Interface functions ******************************************************)
+let message3 m t1 t2 ?mu t3 =    
+   let sm, st1, st2 = "In the context", "the term", "is of type" in
+   match mu with
+      | Some mu ->
+         let smu, st3 = "but in the context", "it must be of type" in
+         L.ct_items3 sm m st1 t1 st2 t2 ~sc3:smu ~c3:mu st3 t3
+      | None    ->
+         let st3 = "but it must be of type" in
+         L.ct_items3 sm m st1 t1 st2 t2 st3 t3
+   
+let error3 m t1 t2 ?mu t3 =
+   raise (TypeError (message3 m t1 t2 ?mu t3))
+
+let assert_convertibility f ~si m u w v =
+   let err _ = error3 m v w u in
+   R.are_convertible err f ~si m u m w 
+
+let assert_applicability f ~si m u w v =
+   let f mu = function
+      | B.Bind (B.Abst (_, u), _) -> 
+         let err _ = error3 m v w ~mu u in 
+         R.are_convertible err f ~si mu u m w
+      | _                         -> error1 "not a function type" m u
+   in
+   R.xwhd f m u 
 
 let rec b_type_of f ~si g m x =
    log1 "Now checking" m x;
    match x with
-   | B.Sort (a, h)           ->
+   | B.Sort (a, h)             ->
       let f h = f x (B.Sort (a, h)) in H.apply f g h
-   | B.LRef (_, i)           ->
-      let f _ = function
-         | B.Abst w                  ->
+   | B.LRef (_, i)             ->
+      let f = function
+         | B.Abst (_, w)                ->
            S.lift (f x) (succ i) (0) w
-        | B.Abbr (B.Cast (_, w, _)) -> 
+        | B.Abbr (_, B.Cast (_, w, _)) -> 
            S.lift (f x) (succ i) (0) w
-        | B.Abbr _                  -> assert false
-        | B.Void                    -> 
+        | B.Abbr _                     -> assert false
+        | B.Void _                     -> 
            error1 "reference to excluded variable" m x
       in
-      R.get f m i
-   | B.GRef (_, uri)         ->
+      let err _ = error1 "reference to unknown variable" m x in
+      R.get err f m i
+   | B.GRef (_, uri)           ->
       let f = function
-         | _, _, B.Abst w                  -> f x w
-        | _, _, B.Abbr (B.Cast (_, w, _)) -> f x w
-        | _, _, B.Abbr _                  -> assert false
-        | _, _, B.Void                    ->
+         | _, _, B.Abst (_, w)                -> f x w
+        | _, _, B.Abbr (_, B.Cast (_, w, _)) -> f x w
+        | _, _, B.Abbr _                     -> assert false
+        | _, _, B.Void _                     ->
            error1 "reference to excluded object" m x
       in
-      E.get_obj f uri   
-   | B.Bind (a, B.Abbr v, t) ->
+      let err _ = error1 "reference to unknown object" m x in
+      E.get_obj err f uri   
+   | B.Bind (B.Abbr (a, v), t) ->
       let f xv xt tt =
          f (A.sh2 v xv t xt x (B.bind_abbr a)) (B.bind_abbr a xv tt)
       in
       let f xv m = b_type_of (f xv) ~si g m t in
-      let f xv = R.push (f xv) m a (B.Abbr xv) in
+      let f xv = R.push (f xv) m (B.abbr a xv) in
       let f xv vv = match xv with 
         | B.Cast _ -> f xv
          | _        -> f (B.Cast ([], vv, xv))
       in
       type_of f ~si g m v
-   | B.Bind (a, B.Abst u, t) ->
+   | B.Bind (B.Abst (a, u), t) ->
       let f xu xt tt =
         f (A.sh2 u xu t xt x (B.bind_abst a)) (B.bind_abst a xu tt)
       in
       let f xu m = b_type_of (f xu) ~si g m t in
-      let f xu _ = R.push (f xu) m a (B.Abst xu) in
+      let f xu _ = R.push (f xu) m (B.abst a xu) in
       type_of f ~si g m u
-   | B.Bind (a, B.Void, t)   ->
+   | B.Bind (B.Void a as b, t) ->
       let f xt tt = 
-         f (A.sh1 t xt x (B.bind a B.Void)) (B.bind a B.Void tt)
+         f (A.sh1 t xt x (B.bind b)) (B.bind b tt)
       in
       let f m = b_type_of f ~si g m t in
-      R.push f m a B.Void   
-   | B.Appl (a, v, t)        ->
+      R.push f m b   
+   | B.Appl (a, v, t)          ->
       let f xv vv xt tt = 
-         let f () = f (A.sh2 v xv t xt x (B.appl a)) (B.appl a xv tt) in
-         R.assert_conversion f ~si ~rt:true m tt vv xv
+         let f _ = f (A.sh2 v xv t xt x (B.appl a)) (B.appl a xv tt) in
+         assert_applicability f ~si m tt vv xv
       in
       let f xv vv = b_type_of (f xv vv) ~si g m t in
       type_of f ~si g m v
-   | B.Cast (a, u, t)        ->
+   | B.Cast (a, u, t)          ->
       let f xu xt tt =  
-        let f () = f (A.sh2 u xu t xt x (B.cast a)) xu in
-         R.assert_conversion f ~si m xu tt xt
+        let f _ = f (A.sh2 u xu t xt x (B.cast a)) xu in
+         assert_convertibility f ~si m xu tt xt
       in
       let f xu _ = b_type_of (f xu) ~si g m t in
       type_of f ~si g m u
 
+(* Interface functions ******************************************************)
+
 and type_of f ?(si=false) g m x =
    let f t u = L.unbox level; f t u in
    L.box level; b_type_of f ~si g m x