2 ||M|| This file is part of HELM, an Hypertextual, Electronic
3 ||A|| Library of Mathematics, developed at the Computer Science
4 ||T|| Department, University of Bologna, Italy.
6 ||T|| HELM is free software; you can redistribute it and/or
7 ||A|| modify it under the terms of the GNU General Public License
8 \ / version 2 or (at your option) any later version.
9 \ / This software is distributed as is, NO WARRANTY.
10 V_______________________________________________________________ *)
19 module E = BrgEnvironment
20 module S = BrgSubstitution
21 module R = BrgReduction
23 exception TypeError of B.message
25 (* Internal functions *******************************************************)
30 let sc, st = s ^ " in the context", "the term" in
31 L.log O.specs level (L.ct_items1 sc c st t)
34 let sc = "In the context" in
35 raise (TypeError (L.ct_items1 sc c st t))
37 let error3 c t1 t2 t3 =
38 let sc, st1, st2, st3 =
39 "In the context", "the term", "is of type", "but must be of type"
41 raise (TypeError (L.ct_items3 sc c st1 t1 st2 t2 st3 t3))
43 (* Interface functions ******************************************************)
47 let rec b_type_of f g c x =
48 (* L.warn "Entering T.b_type_of"; *)
49 log1 "Now checking" c x;
52 let f h = f x (B.Sort (a, h)) in H.apply f g h
55 | Some (_, B.Abst w) ->
56 S.lift (f x) (succ i) (0) w
57 | Some (_, B.Abbr (B.Cast (_, w, _))) ->
58 S.lift (f x) (succ i) (0) w
59 | Some (_, B.Abbr _) -> assert false
61 error1 "reference to excluded variable" c x
63 error1 "variable not found" c x
68 | _, _, B.Abst w -> f x w
69 | _, _, B.Abbr (B.Cast (_, w, _)) -> f x w
70 | _, _, B.Abbr _ -> assert false
72 error1 "reference to excluded object" c x
75 | B.Bind (a, B.Abbr v, t) ->
77 f (A.sh2 v xv t xt x (B.bind_abbr a)) (B.bind_abbr a xv tt)
79 let f xv cc = b_type_of (f xv) g cc t in
80 let f xv = B.push (f xv) c a (B.Abbr xv) in
81 let f xv vv = match xv with
83 | _ -> assert false (* f (B.Cast ([], vv, xv)) *)
86 | B.Bind (a, B.Abst u, t) ->
88 f (A.sh2 u xu t xt x (B.bind_abst a)) (B.bind_abst a xu tt)
90 let f xu cc = b_type_of (f xu) g cc t in
91 let f xu _ = B.push (f xu) c a (B.Abst xu) in
93 | B.Bind (a, B.Void, t) ->
95 f (A.sh1 t xt x (B.bind a B.Void)) (B.bind a B.Void tt)
97 let f cc = b_type_of f g cc t in
100 let f xv vv xt tt = function
103 L.log O.specs (succ level) (L.t_items1 "Just scanned" c w);
104 L.unbox (succ level);
106 (* L.warn (Printf.sprintf "Convertible: %b" a); *)
107 if r then f (A.sh2 v xv t xt x (B.appl a)) (B.appl a xv tt)
108 else error3 c xv vv w
110 R.are_convertible f ~si:!si c w vv
112 error1 "not a function" c xt
114 let f xv vv xt tt = R.domain (f xv vv xt tt) c tt in
115 let f xv vv = b_type_of (f xv vv) g c t in
117 | B.Cast (a, u, t) ->
119 (* L.warn (Printf.sprintf "Convertible: %b" a); *)
120 if r then f (A.sh2 u xu t xt x (B.cast a)) xu else error3 c xt tt xu
122 let f xu xt tt = R.are_convertible ~si:!si (f xu xt tt) c xu tt in
123 let f xu _ = b_type_of (f xu) g c t in
126 and type_of f g c x =
127 let f t u = L.unbox level; f t u in
128 L.box level; b_type_of f g c x