CTMCP Section 2.9 Exercise 6

CTMCP-Section2.9-10.oz

local SMerge in
   fun {SMerge Xs Ys}
      case Xs#Ys
      of nil#Ys then Ys
      [] Xs#nil then Xs
      [] (X|Xr)#(Y|Yr) then
	 if X=<Y then X|{SMerge Xr Ys}
	 else Y|{SMerge Xs Yr} end
      end
   end
   
   {Browse {SMerge [1 3 5 7 9] [4 6 8 10 12]}}
end

local SMerge R in
   SMerge = proc {$ Xs Ys ?R}
	       case Xs of nil then R=Ys
	       else
		  case Ys of nil then R=Xs
		  else
		     case Xs of X|Xr then
			case Ys of Y|Yr then
			   local M in
			      if X=<Y then
				 R = X|M
				 {SMerge Xr Ys M}
			      else
				 R = Y|M
				 {SMerge Xs Yr M}
			      end
			   end
			end
		     end
		  end
	       end
	    end
   
   {PSMerge [1 3 5 7 9] [4 6 8 10 12] R}
   {Browse R}
end