############################################################################
#
#	Name:	 shuffle.icn
#
#	Title:	 Shuffle values
#
#	Author:	 Ward Cunningham and Ralph E. Griswold
#
#	Date:	 February 22, 1990
#
############################################################################
#  
#     The procedure shuffle(x) shuffles a string or list. In the case
#  that x is a string, a corresponding string with the characters
#  randomly rearranged is produced. In the case that x is a list,
#  the values in the list are randomly rearranged.
#  
############################################################################

procedure shuffle(x)
   local i

   x := string(x)		# may fail
   every i := *x to 2 by -1 do
      x[?i] :=: x[i]
   return x
end

#  Note:  the following procedure is simpler, but does not produce
#  as good a shuffle:
#
#procedure shuffle(x)
#   x := string(x)
#   every !x :=: ?x
#   return x
#end