--- /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 C = Cps
+module Y = Entity
+module M = Marks
+module D = Crg
+module B = Brg
+
+(* internal functions: crg to brg term **************************************)
+
+let rec lenv_fold_left map1 map2 x = function
+ | D.ESort -> x
+ | D.EBind (tl, a, b) -> lenv_fold_left map1 map2 (map1 x a b) tl
+ | D.EProj (tl, a, e) -> lenv_fold_left map1 map2 (map2 x a e) tl
+
+let rec xlate_term f = function
+ | D.TSort (a, l) -> f (B.Sort (a, l))
+ | D.TGRef (a, n) -> f (B.GRef (a, n))
+ | D.TLRef (a, _, _) -> let f i = f (B.LRef (a, i)) in Y.apix C.err f a
+ | D.TCast (a, u, t) ->
+ let f uu tt = f (B.Cast (a, uu, tt)) in
+ let f uu = xlate_term (f uu) t in
+ xlate_term f u
+ | D.TAppl (a, vs, t) ->
+ let map f v tt = let f vv = f (B.Appl (a, vv, tt)) in xlate_term f v in
+ let f tt = C.list_fold_right f map vs tt in
+ xlate_term f t
+ | D.TProj (a, e, t) ->
+ let f tt = f (lenv_fold_left xlate_bind xlate_proj tt e) in
+ xlate_term f t
+ | D.TBind (ab, D.Abst ws, D.TCast (ac, u, t)) ->
+ xlate_term f (D.TCast (ac, D.TBind (ab, D.Abst ws, u), D.TBind (ab, D.Abst ws, t)))
+ | D.TBind (a, b, t) ->
+ let f tt = f (xlate_bind tt a b) in xlate_term f t
+
+and xlate_bind x a b =
+ let f a ns = a, ns in
+ let a, ns = Y.get_names f a in
+ match b with
+ | D.Abst ws ->
+ let map x n w =
+ let f ww = B.Bind (n :: M.new_mark () :: a, B.Abst ww, x) in
+ xlate_term f w
+ in
+ List.fold_left2 map x ns ws
+ | D.Abbr vs ->
+ let map x n v =
+ let f vv = B.Bind (n :: a, B.Abbr vv, x) in
+ xlate_term f v
+ in
+ List.fold_left2 map x ns vs
+ | D.Void _ ->
+ let map x n = B.Bind (n :: a, B.Void, x) in
+ List.fold_left map x ns
+
+and xlate_proj x _ e =
+ lenv_fold_left xlate_bind xlate_proj x e
+
+(* internal functions: brg to crg term **************************************)
+
+let rec xlate_bk_term f = function
+ | B.Sort (a, l) -> f (D.TSort (a, l))
+ | B.GRef (a, n) -> f (D.TGRef (a, n))
+ | B.LRef (a, i) -> f (D.TLRef (a, i, 0))
+ | B.Cast (a, u, t) ->
+ let f uu tt = f (D.TCast (a, uu, tt)) in
+ let f uu = xlate_bk_term (f uu) t in
+ xlate_bk_term f u
+ | B.Appl (a, u, t) ->
+ let f uu tt = f (D.TAppl (a, [uu], tt)) in
+ let f uu = xlate_bk_term (f uu) t in
+ xlate_bk_term f u
+ | B.Bind (a, b, t) ->
+ let f bb tt = f (D.TBind (a, bb, tt)) in
+ let f bb = xlate_bk_term (f bb) t in
+ xlate_bk_bind f b
+
+and xlate_bk_bind f = function
+ | B.Abst t ->
+ let f tt = f (D.Abst [tt]) in
+ xlate_bk_term f t
+ | B.Abbr t ->
+ let f tt = f (D.Abbr [tt]) in
+ xlate_bk_term f t
+ | B.Void -> f (D.Void 1)
+
+(* interface functions ******************************************************)
+
+let brg_of_crg f t =
+ f (xlate_term C.start t)
+
+let crg_of_brg = xlate_bk_term