From fa143d13b855aa48a11f3230a139f39ce2df0984 Mon Sep 17 00:00:00 2001
From: Luca Padovani <luca.padovani@unito.it>
Date: Mon, 11 Jul 2005 13:54:09 +0000
Subject: [PATCH] * added backtracking in matching code (hairy code!)

---
 helm/ocaml/cic_notation/TODO                   |  8 ++++----
 helm/ocaml/cic_notation/cicNotationMatcher.ml  | 18 +++++++++++++-----
 helm/ocaml/cic_notation/cicNotationMatcher.mli |  6 +++---
 3 files changed, 20 insertions(+), 12 deletions(-)

diff --git a/helm/ocaml/cic_notation/TODO b/helm/ocaml/cic_notation/TODO
index 2ba0283ce..73a2a49a6 100644
--- a/helm/ocaml/cic_notation/TODO
+++ b/helm/ocaml/cic_notation/TODO
@@ -3,25 +3,25 @@ TODO
 
 * implementare trasformazione 1 => 0
 * gestione priorita'/associativita'
-  - annotazioni nel livello 1 generato?
   - triplicare livelli nella grammatica?
 * implementare type-checker per le trasformazioni
 * prestazioni trasformazioni 3 => 2 e 2 => 1
-* problema con pattern overlapping per i magic al livello 2
 * magic per gestione degli array?
 * gestione speciale dei numeri
-* gestione greedyness dei magic in 2 => 1
 * sintassi concreta / prelexing
   - studiare/implementare sintassi con ... per i magic fold
 * integrazione
   - porting della disambiguazione al nuovo ast
   - apportare all'ast le modifiche di CicAst (case, cast non come annotazione,
     tipi opzionali nel let rec e nelle definizioni)
-* href multipli
 
 DONE
 
 * implementare istanziazione dei magic a livello 1 (2 => 1)
 * implementare compilazione dei default in 2 => 1
   -> Tue, 07 Jun 2005 17:17:36 +0200 zack
+* annotazioni nel livello 1 generato
+* problema con pattern overlapping per i magic al livello 2
+* gestione greedyness dei magic in 2 => 1
+* href multipli
 
diff --git a/helm/ocaml/cic_notation/cicNotationMatcher.ml b/helm/ocaml/cic_notation/cicNotationMatcher.ml
index 6b1266ec8..1a0c02410 100644
--- a/helm/ocaml/cic_notation/cicNotationMatcher.ml
+++ b/helm/ocaml/cic_notation/cicNotationMatcher.ml
@@ -139,7 +139,18 @@ struct
         k
       else if are_empty t then
         let res = match_cb (matched t) in
-        (fun matched_terms _ -> res matched_terms)
+        (fun matched_terms terms ->
+	   match res matched_terms with
+	       None ->
+		 begin
+		   (* the match has failed, we rollback the last matched term
+		    * into the unmatched ones and call the failure continuation
+		    *)
+		   match matched_terms with
+		       hd :: tl -> k tl (hd :: terms)
+		     | _ -> assert false
+		 end
+	     | Some v -> Some v)
       else
         match horizontal_split t with
         | _, [], _ -> assert false
@@ -331,12 +342,9 @@ struct
 	  (fun term env ->
 	     prerr_endline "GUARDIA?" ;
 	     match compiled_guard term with
-	       | None -> 
-		   prerr_endline "SONO CAZZI H2SO4" ;
-		   None
+	       | None -> None
 	       | Some _ ->
 		   begin
-		     prerr_endline "OKKKKKKKKKKKKKK" ;
 		     match compiled_p term with
 		       | None -> None
 		       | Some (env', _) ->
diff --git a/helm/ocaml/cic_notation/cicNotationMatcher.mli b/helm/ocaml/cic_notation/cicNotationMatcher.mli
index 55de82999..4abb5b8bc 100644
--- a/helm/ocaml/cic_notation/cicNotationMatcher.mli
+++ b/helm/ocaml/cic_notation/cicNotationMatcher.mli
@@ -39,9 +39,9 @@ module Matcher (P: PATTERN) :
 sig
   val compiler:
     (P.pattern_t * int) list ->
-    ((P.pattern_t list * int) list -> P.term_t list -> 'a) ->
-    (unit -> 'a) ->
-      (P.term_t -> 'a)
+    ((P.pattern_t list * int) list -> P.term_t list -> 'a option) ->
+    (unit -> 'a option) ->
+      (P.term_t -> 'a option)
 end
 
 module Matcher21:
-- 
2.39.2