[r2006-09-09 20:16:08 by afrisch] Print regexp of the form [ t? ... ]

Original author: afrisch
Date: 2006-09-09 20:16:08+00:00

misc/pretty.ml

@@ -497,9 +497,12 @@ module Decompile(H : TABLE)(S : S) = struct
       let s = slot n in
       if not s.ok then (
 	s.ok <- true;
-	let (tr,f) = trans n in
-	if f then add_trans s final epsilon;
-	List.iter (fun (l,dst) -> add_trans s (conv dst) (rtrans l)) tr;
+	match trans n with
+	  | `T (tr,f) ->
+	      if f then add_trans s final epsilon;
+	      List.iter (fun (l,dst) -> add_trans s (conv dst) (rtrans l)) tr
+	  | `Eps (l,dst) ->
+	      add_trans s (conv dst) (alt (rtrans l) epsilon)
       );
       s in
 

misc/pretty.mli

@@ -26,5 +26,7 @@ end
 
 module Decompile(X : TABLE)(S : S)
 : sig
-  val decompile: (X.key -> (S.t * X.key) list * bool) -> X.key -> S.t regexp
+  val decompile: (X.key -> [ `T of (S.t * X.key) list * bool
+                           | `Eps of S.t * X.key]
+			   ) -> X.key -> S.t regexp
 end

types/types.ml

@@ -1544,8 +1544,26 @@ struct
 	 let tr = Product.get t in 
 	 let tr = Product.clean_normal tr in
 
-	 let tr = List.map (fun (l,t) -> prepare l, t) tr in
-	 tr, Atoms.contains nil_atom t.atoms)
+	 let eps = Atoms.contains nil_atom t.atoms in
+	 let tr_cons = List.map (fun (li,ti) -> (cons li, cons ti)) tr in
+
+	 try
+	   let (l0,t0) = List.find
+	     (fun ((l0,t0) as tr0) ->
+	       let t'' = 
+		 List.fold_left
+		   (fun accu ((li,ti) as tri) ->
+		     if tr0 == tri then accu
+		     else cup accu (times li ti)
+		   )
+		   (if eps then nil_type else empty) 
+		   tr_cons
+	       in
+	       equiv (descr t0) t'' ) tr_cons in
+	   `Eps (prepare (descr l0), descr t0)
+	 with Not_found -> 
+	   let tr = List.map (fun (l,t) -> prepare l, t) tr in
+	   `T (tr, eps))
       d
 
   let gen = ref 0