brg: change in the representation of binders

[helm.git] / helm / software / lambda-delta / basic_rg / brg.ml

diff --git a/helm/software/lambda-delta/basic_rg/brg.ml b/helm/software/lambda-delta/basic_rg/brg.ml
index 4778e5c3e9ef8716a46ccff050ecb211eef90eda..fd93f397af56bf450ce8ef1452697f004ce7b3e5 100644 (file)
--- a/helm/software/lambda-delta/basic_rg/brg.ml
+++ b/helm/software/lambda-delta/basic_rg/brg.ml
@@ -9,27 +9,34 @@
      \ /   This software is distributed as is, NO WARRANTY.              
       V_______________________________________________________________ *)
 
-type uri = NUri.uri
-type id = Aut.id
+(* kernel version: basic, relative, global *)
+(* note          : ufficial basic lambda-delta *) 
 
-type bind = Void         (* exclusion *)
-          | Abst of term (* abstraction *)
-          | Abbr of term (* abbreviation *)
+type uri = Entity.uri
+type id = Entity.id
+type attrs = Entity.attrs
 
-and term = Sort of int              (* hierarchy index *)
-         | LRef of int              (* reverse de Bruijn index *)
-         | GRef of uri              (* reference *)
-         | Cast of term * term      (* type, term *)
-         | Appl of term * term      (* argument, function *)
-         | Bind of id * bind * term (* name, binder, scope *)
+type bind = Void         (*      *)
+          | Abst of term (* type *)
+          | Abbr of term (* body *)
 
-type obj = int * uri * bind (* age, uri, binder, contents *)
+and term = Sort of attrs * int         (* attrs, hierarchy index *)
+         | LRef of attrs * int         (* attrs, position index *)
+         | GRef of attrs * uri         (* attrs, reference *)
+         | Cast of attrs * term * term (* attrs, type, term *)
+         | Appl of attrs * term * term (* attrs, argument, function *)
+         | Bind of attrs * bind * term (* attrs, binder, scope *)
 
-type item = obj option
+type entity = term Entity.entity (* attrs, uri, binder *)
 
-type context = int * (id * bind) list
+type lenv = Null
+(* Cons: tail, relative local environment, attrs, binder *) 
+          | Cons of lenv * lenv * attrs * bind 
 
-type message = (context, term) Log.item list
+(* helpers ******************************************************************)
+
+let mk_uri root s =
+   String.concat "/" ["ld:"; "brg"; root; s ^ ".ld"]
 
 (* Currified constructors ***************************************************)
 
@@ -37,31 +44,39 @@ let abst w = Abst w
 
 let abbr v = Abbr v
 
-let cast u t = Cast (u, t)
+let lref a i = LRef (a, i)
+
+let cast a u t = Cast (a, u, t)
+
+let appl a u t = Appl (a, u, t)
+
+let bind a b t = Bind (a, b, t)
 
-let appl u t = Appl (u, t)
+let bind_abst a u t = Bind (a, Abst u, t)
 
-let bind id b t = Bind (id, b, t)
+let bind_abbr a v t = Bind (a, Abbr v, t)
 
-(* context handling functions ***********************************************)
+let bind_void a t = Bind (a, Void, t)
 
-let empty_context = 0, []
+(* local environment handling functions *************************************)
 
-let push f (l, es) id b =
-   let c = succ l, (id, b) :: es in 
-   f c
+let empty = Null
 
-let append f (l1, es1) (l2, es2) =
-   f (l2 + l1, List.append es2 es1)
+let push e c a b = Cons (e, c, a, b)
 
-let map f map (l, es) =
-   let f es = f (l, es) in
-   Cps.list_map f map es
+let rec get i = function
+   | Null                         -> Null, Null, [], Void
+   | Cons (e, c, a, b) when i = 0 -> e, c, a, b
+   | Cons (e, _, _, _)            -> get (pred i) e
 
-let contents f (l, es) = f l es
+let get e i = get i e
 
-let get f (l, es) i =
-   if i < 0 || i >= l then f None else 
-   let result = List.nth es (l - succ i) in
-   f (Some result)
+(* used in BrgOutput.pp_lenv *)
+let rec fold_right f map e x = match e with   
+   | Null              -> f x
+   | Cons (e, c, a, b) -> fold_right (map f e c a b) map e x
 
+(* used in MetaBrg.unwind_to_xlate_term *)
+let rec fold_left map x = function
+   | Null              -> x
+   | Cons (e, _, a, b) -> fold_left map (map x a b) e