X-Git-Url: http://git.joshuawise.com/snipe.git/blobdiff_plain/12aa4087bee3e70f170d7457794921de4e385227..0a24e44d4e9f82f8d3d83de8e58c83c8cf2868b6:/trans/label.sml

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+(* L2 Compiler
+ * Labeloraries
+ * Like temporaries, except more different
+ * Author: Joshua Wise <jwise@cs.cmu.edu>
+ *)
+
+signature LABEL = 
+sig
+  type label
+
+  val reset : unit -> unit	(* resets label numbering *)
+  val new : unit -> label	(* returns a unique new label *)
+  val name : label -> string	(* returns the name of a label *)
+  val compare : label * label -> order (* comparison function *)
+end
+
+structure Label :> LABEL = 
+struct
+  type label = int
+
+  local
+    val counter = ref 1
+  in
+    (* warning: calling reset() may jeopardize uniqueness of labels! *)
+    fun reset () = ( counter := 1 )
+    fun new () = !counter before ( counter := !counter + 1 )
+  end
+
+  fun name t = ".L" ^ Int.toString t
+		      
+  fun compare (t1,t2) = Int.compare (t1,t2)
+end