-(*
- ||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 C = Cps
-module E = Entity
-module J = Marks
-module N = Level
-module D = Crg
-module Z = Bag
-
-(* internal functions: crg to bag term **************************************)
-
-let rec shift t = function
- | _, [] -> t
- | (a, l, b) :: c, _ :: ns -> shift (Z.Bind (a, l, b, t)) (c, ns)
- | _ -> assert false
-
-let rec xlate_term xlate_bind f c = function
- | D.TSort (_, h) -> f (Z.Sort h)
- | D.TGRef (_, s) -> f (Z.GRef s)
- | D.TLRef (a, _, _) ->
- let f i =
- let _, l, _ = List.nth c i in
- f (Z.LRef l)
- in
- E.apix C.err f a
- | D.TCast (_, u, t) ->
- let f tt uu = f (Z.Cast (uu, tt)) in
- let f tt = xlate_term xlate_bind (f tt) c u in
- xlate_term xlate_bind f c t
- | D.TAppl (_, vs, t) ->
- let map f v tt = let f vv = f (Z.Appl (vv, tt)) in xlate_term xlate_bind f c v in
- let f tt = C.list_fold_right f map vs tt in
- xlate_term xlate_bind f c t
- | D.TProj (_, e, t) ->
- xlate_term xlate_bind f c (D.tshift e t)
-(* this case should be removed by improving alpha-conversion *)
- | D.TBind (ab, D.Abst (n, ws), D.TCast (ac, u, t)) ->
- xlate_term xlate_bind f c (D.TCast (ac, D.TBind (ab, D.Abst (N.pred n, ws), u), D.TBind (ab, D.Abst (n, ws), t)))
- | D.TBind (a, b, t) ->
- let g _ ns = ns in
- let ns = E.get_names g a in
- let cc = xlate_bind C.start c ns b in
- let f tt = f (shift tt (cc, ns)) in
- xlate_term xlate_bind f cc t
-
-let rec xlate_bind f c ns = function
- | D.Abst (_, ws) ->
- let map f n w c =
- let f ww = Z.push "xlate_bind" f c [n] (J.new_location ()) (Z.Abst ww) in
- xlate_term xlate_bind f c w
- in
- C.list_fold_right2 f map ns ws c
- | D.Abbr vs ->
- let map f n v c =
- let f vv = Z.push "xlate_bind" f c [n] (J.new_location ()) (Z.Abbr vv) in
- xlate_term xlate_bind f c v
- in
- C.list_fold_right2 f map ns vs c
- | D.Void _ ->
- let map f n c = Z.push "xlate_bind" f c [n] (J.new_location ()) Z.Void in
- C.list_fold_right f map ns c
-
-(* internal functions: bag to crg term **************************************)
-
-let rec xlate_bk_term f c = function
- | Z.Sort h -> f (D.TSort ([], h))
- | Z.GRef s -> f (D.TGRef ([], s))
- | Z.LRef l ->
- let f i = f (D.TLRef ([], i, 0)) in
- Z.nth C.err f l c
- | Z.Cast (u, t) ->
- let f tt uu = f (D.TCast ([], uu, tt)) in
- let f tt = xlate_bk_term (f tt) c u in
- xlate_bk_term f c t
- | Z.Appl (u, t) ->
- let f tt uu = f (D.TAppl ([], [uu], tt)) in
- let f tt = xlate_bk_term (f tt) c u in
- xlate_bk_term f c t
- | Z.Bind (a, l, b, t) ->
- let f tt bb = f (D.TBind (a, bb, tt)) in
- let f tt = xlate_bk_bind (f tt) c b in
- let cc = Z.push "xlate_bk_term" C.start c a l b in
- xlate_bk_term f cc t
-
-and xlate_bk_bind f c = function
- | Z.Abst t ->
- let f tt = f (D.Abst (N.infinite, [tt])) in
- xlate_bk_term f c t
- | Z.Abbr t ->
- let f tt = f (D.Abbr [tt]) in
- xlate_bk_term f c t
- | Z.Void -> f (D.Void 1)
-
-(* interface functions ******************************************************)
-
-let bag_of_crg f t =
- xlate_term xlate_bind f Z.empty_lenv t
-
-let crg_of_bag f t = xlate_bk_term f Z.empty_lenv t