--- /dev/null
+(*
+ ||M|| This file is part of HELM, an Hypertextual, Electronic
+ ||A|| Library of Mathematics, developed at the Computer Science
+ ||T|| Department, University of Bologna, Italy.
+ ||I||
+ ||T|| HELM is free software; you can redistribute it and/or
+ ||A|| modify it under the terms of the GNU General Public License
+ \ / version 2 or (at your option) any later version.
+ \ / This software is distributed as is, NO WARRANTY.
+ V_______________________________________________________________ *)
+
+module U = NUri
+module S = Share
+module L = Log
+module H = Hierarchy
+module I = AutItem
+module B = Bag
+module O = BagOutput
+module E = BagEnvironment
+module R = BagReduction
+
+exception TypeError of B.message
+
+(* Internal functions *******************************************************)
+
+let level = 4
+
+let error1 s c t =
+ raise (TypeError (L.ct_items1 s c t))
+
+let error2 s1 c1 t1 s2 c2 t2 =
+ raise (TypeError (L.ct_items2 s1 c1 t1 s2 c2 t2))
+
+let mk_gref u l =
+ let map t v = B.Appl (v, t) in
+ List.fold_left map (B.GRef u) l
+
+(* Interface functions ******************************************************)
+
+let rec b_type_of f g c x =
+ L.log O.specs level (L.ct_items1 "Now checking" c x);
+ match x with
+ | B.Sort h ->
+ let f h = f x (B.Sort h) in H.apply f g h
+ | B.LRef i ->
+ let f = function
+ | Some (_, B.Abst w) -> f x w
+ | Some (_, B.Abbr (B.Cast (w, v))) -> f x w
+ | Some (_, B.Abbr _) -> assert false
+ | Some (_, B.Void) ->
+ error1 "reference to excluded variable" c x
+ | None ->
+ error1 "variable not found" c x
+ in
+ B.get f c i
+ | B.GRef uri ->
+ let f = function
+ | _, _, B.Abst w -> f x w
+ | _, _, B.Abbr (B.Cast (w, v)) -> f x w
+ | _, _, B.Abbr _ -> assert false
+ | _, _, B.Void ->
+ error1 "reference to excluded object" c x
+ in
+ E.get_obj f uri
+ | B.Bind (l, id, B.Abbr v, t) ->
+ let f xv xt tt =
+ f (S.sh2 v xv t xt x (B.bind_abbr l id)) (B.bind_abbr l id xv tt)
+ in
+ let f xv cc = b_type_of (f xv) g cc t in
+ let f xv = B.push (f xv) c l id (B.Abbr xv) in
+ let f xv vv = match xv with
+ | B.Cast _ -> f xv
+ | _ -> f (B.Cast (vv, xv))
+ in
+ type_of f g c v
+ | B.Bind (l, id, B.Abst u, t) ->
+ let f xu xt tt =
+ f (S.sh2 u xu t xt x (B.bind_abst l id)) (B.bind_abst l id xu tt)
+ in
+ let f xu cc = b_type_of (f xu) g cc t in
+ let f xu _ = B.push (f xu) c l id (B.Abst xu) in
+ type_of f g c u
+ | B.Bind (l, id, B.Void, t) ->
+ let f xt tt =
+ f (S.sh1 t xt x (B.bind l id B.Void)) (B.bind l id B.Void tt)
+ in
+ let f cc = b_type_of f g cc t in
+ B.push f c l id B.Void
+ | B.Appl (v, t) ->
+ let h xv vv xt tt cc = function
+ | R.Sort _ -> error1 "not a function" c xt
+ | R.Abst w ->
+ L.box ();
+ L.log O.specs (succ level) (L.ct_items1 "Just scanned" cc w);
+ L.unbox ();
+ let f b =
+ if b then f (S.sh2 v xv t xt x B.appl) (B.appl xv tt) else
+ error2 "the term" cc xv "must be of type" cc w
+ in
+ R.are_convertible f cc w vv
+ in
+ let f xv vv xt = function
+(* inserting a missing "modus ponens" *)
+ | B.Appl (y2, B.Appl (y1, B.GRef u)) when U.eq u I.imp ->
+ b_type_of f g c (mk_gref I.mp [y1; y2; xv; xt])
+ | tt -> R.ho_whd (h xv vv xt tt) c tt
+ in
+ let f xv vv = b_type_of (f xv vv) g c t in
+ type_of f g c v
+ | B.Cast (u, t) ->
+ let f xu xt b =
+ if b then f (S.sh2 u xu t xt x B.cast) xu else
+ error2 "the term" c xt "must be of type" c xu
+ in
+ let f xu xt tt = R.are_convertible (f xu xt) c xu tt in
+ let f xu _ = b_type_of (f xu) g c t in
+ type_of f g c u
+
+and type_of f g c x =
+ let f t u = L.unbox (); f t u in
+ L.box (); b_type_of f g c x
projects / helm.git / blobdiff