refactoring ...

[helm.git] / helm / software / helena / src / complete_rg / crg.ml

diff --git a/helm/software/helena/src/complete_rg/crg.ml b/helm/software/helena/src/complete_rg/crg.ml
new file mode 100644 (file)
index 0000000..5a394f4
--- /dev/null
+++ b/helm/software/helena/src/complete_rg/crg.ml
@@ -0,0 +1,133 @@
+(*
+    ||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: complete, relative, global *)
+(* note          : fragment of complete lambda-delta serving as abstract layer *) 
+
+module C = Cps
+module E = Entity
+module N = Level
+
+type uri = E.uri
+type id = E.id
+type attrs = E.attrs
+
+type bind = Abst of N.level * term list (* level, domains *)
+          | Abbr of term list           (* bodies *)
+          | Void of int                 (* number of exclusions *)
+
+and term = TSort of attrs * int              (* attrs, hierarchy index *)
+         | TLRef of attrs * int * int        (* attrs, position indexes *)
+         | TGRef of attrs * uri              (* attrs, reference *)
+         | TCast of attrs * term * term      (* attrs, domain, element *)
+         | TAppl of attrs * term list * term (* attrs, arguments, function *)
+        | TProj of attrs * lenv * term      (* attrs, closure, member *)
+        | TBind of attrs * bind * term      (* attrs, binder, scope *)
+
+and lenv = ESort                        (* top *)
+         | EProj of lenv * attrs * lenv (* environment, attrs, closure *) 
+         | EBind of lenv * attrs * bind (* environment, attrs, binder *)
+
+type entity = term E.entity
+
+(* helpers ******************************************************************)
+
+let rec tshift t = function
+   | ESort           -> t
+   | EBind (e, a, b) -> tshift (TBind (a, b, t)) e
+   | EProj (e, a, d) -> tshift (TProj (a, d, t)) e
+
+let tshift c t = tshift t c
+
+let rec eshift f c = function
+   | ESort           -> f c
+   | EBind (e, a, b) -> let f ee = f (EBind (ee, a, b)) in eshift f c e
+   | EProj (e, a, d) -> let f ee = f (EProj (ee, a, d)) in eshift f c e
+
+let empty_lenv = ESort
+
+let push_bind f lenv a b = f (EBind (lenv, a, b))
+
+let push_proj f lenv a e = f (EProj (lenv, a, e))
+
+let push2 err f lenv ?attr ?t () = match lenv, attr, t with
+   | EBind (e, a, Abst (n, ws)), Some attr, Some t -> 
+      f (EBind (e, (attr :: a), Abst (n, t :: ws)))
+   | EBind (e, a, Abst (n, ws)), None, Some t      -> 
+      f (EBind (e, a, Abst (n, t :: ws)))
+   | EBind (e, a, Abbr vs), Some attr, Some t      ->
+      f (EBind (e, (attr :: a), Abbr (t :: vs)))
+   | EBind (e, a, Abbr vs), None, Some t           ->
+      f (EBind (e, a, Abbr (t :: vs)))
+   | EBind (e, a, Void n), Some attr, None         ->
+      f (EBind (e, (attr :: a), Void (succ n)))
+   | EBind (e, a, Void n), None, None              ->
+      f (EBind (e, a, Void (succ n)))
+   | _                                             -> err ()
+
+(* this id not tail recursive *)
+let resolve_lref err f id lenv =
+   let rec aux f i k = function
+     | ESort                  -> err ()
+     | EBind (tl, _, Abst (_, []))
+     | EBind (tl, _, Abbr [])
+     | EBind (tl, _, Void 0)  -> aux f i k tl
+     | EBind (tl, a, b)       ->
+       let err kk = aux f (succ i) (k + kk) tl in
+       let f j = f i j (k + j) in
+       E.resolve err f id a
+     | EProj (tl, _, d)       -> aux f i k (eshift C.start tl d)
+   in
+   aux f 0 0 lenv
+
+let rec get_name err f i j = function
+   | ESort                      -> err i
+   | EBind (tl, _, Abst (_, []))
+   | EBind (tl, _, Abbr [])
+   | EBind (tl, _, Void 0)      -> get_name err f i j tl
+   | EBind (_, a, _) when i = 0 -> 
+      let err () = err i in
+      E.get_name err f j a
+   | EBind (tl, _, _)           -> 
+      get_name err f (pred i) j tl
+   | EProj (tl, _, e)           ->
+      let err i = get_name err f i j tl in 
+      get_name err f i j e
+
+let get_index err f i j lenv =
+   let rec aux f i k = function
+      | ESort                      -> err i
+      | EBind (tl, _, Abst (_, []))
+      | EBind (tl, _, Abbr [])
+      | EBind (tl, _, Void 0)      -> aux f i k tl
+      | EBind (_, a, _) when i = 0 ->
+        if E.count_names a > j then f (k + j) else err i
+      | EBind (tl, a, _)           -> 
+         aux f (pred i) (k + E.count_names a) tl
+      | EProj (tl, _, d)           -> aux f i k (eshift C.start tl d)
+   in
+   aux f i 0 lenv
+
+let rec names_of_lenv ns = function
+   | ESort            -> ns
+   | EBind (tl, a, _) -> names_of_lenv (E.rev_append_names ns a) tl
+   | EProj (tl, _, e) -> names_of_lenv (names_of_lenv ns e) tl
+
+let rec get i = function
+   | ESort                      -> ESort, [], Void 0 
+   | EBind (e, _, Abst (_, []))
+   | EBind (e, _, Abbr [])
+   | EBind (e, _, Void 0)       -> get i e
+   | EBind (e, a, b) when i = 0 -> e, a, b
+   | EBind (e, _, _)            -> get (pred i) e
+   | EProj (e, _, d)            -> get i (eshift C.start e d)
+ 
+let get e i = get i e