(**
 	Module: Beam	
	Description: beam definition and operations
	@author WANG Haisheng	
	Created: 21/07/2013	Modified: 21/07/2013
*)

exception Beam_matching of string;;

open Signal;;

class beam : signal_type array -> beam_type = 
  fun (sa_init : signal_type array) ->
    object (self)
      val sa = sa_init
      val l = Array.length sa

      method get = sa

      method length = l

      method sub : int -> int -> beam_type = 
	fun start ->
	  fun len ->
	    new beam (Array.sub self#get start len)

      method append : beam_type -> beam_type =
	fun b -> 
	  new beam (Array.append self#get b)
	  
      method matching : int -> beam_type
	  fun size ->
	    if size = self#length then self
	    else if size > self#length && size mod self#length = 0 then
	      
	    else if size < self#length && self#length mod size = 0 then
	      
	    else raise (Beam_matching "matching size error")


    end