X-Git-Url: https://scm.cri.mines-paristech.fr/git/Faustine.git/blobdiff_plain/440ca0ba93966e89b68dc54207c461afc0d56264..14bec4f1c7b97b6415f2816df7fd0d1ba9c95cf1:/interpretor/signal.ml

diff --git a/interpretor/signal.ml b/interpretor/signal.ml
index b493b6c..2dd9f73 100644
--- a/interpretor/signal.ml
+++ b/interpretor/signal.ml
@@ -32,7 +32,7 @@ class signal : int -> (time -> value_type) -> signal_type =
 		  else raise (Signal_operation "frequency not matched.") in
 	    List.fold_left check self#frequency sl
 
-	method private add_memory : int -> unit = 
+	method add_memory : int -> unit = 
 	  fun (length : int) ->
 	    assert (length >= 0);
 	    if memory_length >= length then ()
@@ -98,13 +98,13 @@ class signal : int -> (time -> value_type) -> signal_type =
 	    let func : time -> value_type = 
 	      fun (t : time) ->
 		let i = (s#at t)#to_int in
-		self#delay_by t i  in
+		self#delay_by i t  in
 	    new signal freq func
 
 	method mem : signal_type = 
 	  let freq = self#frequency in
 	  let () = self#add_memory 1 in
-	  let func = fun (t : time) -> self#delay_by t 1 in
+	  let func = fun (t : time) -> self#delay_by 1 t in
 	  new signal freq func
 
 	method rdtable : signal_type -> signal_type -> signal_type = 
@@ -141,10 +141,11 @@ class signal : int -> (time -> value_type) -> signal_type =
 		    
 	method prefix : signal_type -> signal_type =
 	    fun (s_init : signal_type) ->
+	      let () = self#add_memory 1 in
 	      let func : time -> value_type = 
 		fun t ->
 		  if t = 0 then s_init#at 0
-		  else if t > 0 then self#at t
+		  else if t > 0 then self#at (t - 1) 
 		  else raise (Signal_operation "prefix time < 0.") in
 	      new signal self#frequency func