basic palindrome exercise

palindrome.erl

-module(palindrome).
-export([server/1]).



rem_punct(String) -> lists:filter(fun (Ch) ->
                                      not(lists:member(Ch,"\"\'\t\n "))
                                    end,
                                    String).

to_small(String) -> lists:map(fun(Ch) ->
                                  case ($A =< Ch andalso Ch =< $Z) of
                                      true -> Ch+32;
                                      false -> Ch
                                   end
                                 end,
                                 String).

palindrome_check(String) ->
    Normalise = to_small(rem_punct(String)),
    lists:reverse(Normalise) == Normalise.


server(PID) ->
	  receive
		    {message,String} -> 
			        case palindrome_check(String) of
				          true -> PID ! String ++ " is a palindrome", server(PID);
				          false -> PID ! String ++ " isn't a palindrome", server(PID) 
			          end;
       	 _  -> PID ! stop 
	end.







%2> Palindrome = spawn(palindrome,server,[Self]).
%<0.82.0>
%3> Palindrome ! {message,"test"}, receive X -> X end.   
%"test isn't a palindrome"