-(*
- ||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_______________________________________________________________ *)
-
-(* kernel version: basic, absolute, global *)
-(* note : experimental *)
-
-module E = Entity
-
-type uri = E.uri
-type attrs = E.attrs
-
-type bind = Void (* exclusion *)
- | Abst of term (* abstraction *)
- | Abbr of term (* abbreviation *)
-
-and term = Sort of int (* hierarchy index *)
- | LRef of int (* location *)
- | GRef of uri (* reference *)
- | Cast of term * term (* domain, element *)
- | Appl of term * term (* argument, function *)
- | Bind of attrs * int * bind * term (* name, location, binder, scope *)
-
-type entity = term E.entity (* attrs, uri, binder *)
-
-type lenv = (attrs * int * bind) list (* location, name, binder *)
-
-type message = (lenv, term) Log.item list
-
-(* Currified constructors ***************************************************)
-
-let abst w = Abst w
-
-let abbr v = Abbr v
-
-let lref i = LRef i
-
-let cast u t = Cast (u, t)
-
-let appl u t = Appl (u, t)
-
-let bind a l b t = Bind (a, l, b, t)
-
-let bind_abst a l u t = Bind (a, l, Abst u, t)
-
-let bind_abbr a l v t = Bind (a, l, Abbr v, t)
-
-(* local environment handling functions *************************************)
-
-let empty_lenv = []
-
-let push msg f es a l b =
- let rec does_not_occur loc = function
- | [] -> true
- | (_, l, _) :: _ when l = loc -> false
- | _ :: es -> does_not_occur l es
- in
- if not (does_not_occur l es) then failwith msg else
- let c = (a, l, b) :: es in f c
-
-let append f es1 es2 =
- f (List.append es2 es1)
-
-let map f map es =
- Cps.list_map f map es
-
-let contents f es = f es
-
-let get err f es i =
- let rec aux = function
- | [] -> err ()
- | (a, l, b) :: tl -> if l = i then f a b else aux tl
- in
- aux es
-
-let nth err f loc e =
- let rec aux n = function
- | [] -> err loc
- | (_, l, _) :: _ when l = loc -> f n
- | _ :: e -> aux (succ n) e
- in
- aux 0 e