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 97872734b3480a1a48510aa63cca1fb72851f3a7..96c9cb52ab01051f91ac7ac868816504be339eda 100644 (file)
--- a/helm/software/lambda-delta/basic_rg/brgType.ml
+++ b/helm/software/lambda-delta/basic_rg/brgType.ml
@@ -20,18 +20,47 @@ 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;
@@ -48,7 +77,8 @@ let rec b_type_of f ~si g m x =
         | B.Void _                     -> 
            error1 "reference to excluded variable" m x
       in
-      R.get f m i
+      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
@@ -57,7 +87,8 @@ let rec b_type_of f ~si g m x =
         | _, _, B.Void _                     ->
            error1 "reference to excluded object" m x
       in
-      E.get_obj f uri   
+      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)
@@ -84,19 +115,21 @@ let rec b_type_of f ~si g m x =
       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)          ->
       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