gistfile1.erl

-module(useless).
-export([add/2, hello/0, greet_and_add_two/1, len/1, tail_fac/1, tail_fac/2]).
 
add(A,B) ->
	A + B.
 
%% Shows greetings.
%% io:format/1 is the standard function used to output text.
hello() ->
	io:format("Hello, world!~n").
 
greet_and_add_two(X) ->
	hello(),
	add(X,2).

len([]) -> 0;
len([_|T]) -> 1 + len(T).

tail_fac(N) -> tail_fac(N,1).

tail_fac(0, Acc) -> Acc;
tail_fac(N,Acc) when N > 0 -> tail_fac(N-1, N*Acc).