Tail recursive lists

w2lists.erl

-module(w2lists).

-export([prod/1,mymax/1,test/0]).

%Moddified according Elbrujohalcon:
%Removed the "list is emty" function clause as we will let it crash.
%prod([]) -> 
%	"list is empty";
prod([H|T]) -> 
        prod(T,H).

%Tail recursive prod.
prod([],Acc) -> 
	Acc;
prod([H|T],Acc) -> 
	prod(T,Acc * H).

%The product of an empty list is usually taken to be 1: why?
%because Acc starts by 1.
%This could be avoided by,for example, verifying that the list is not empty before calling prod/2.
% 
%Moddified according Elbrujohalcon:
%Removed the "list is emty" function clause as we will let it crash.
%mymax([]) -> 
%	"list is empty";
mymax([H|T]) -> 
	mymax(T,H).

mymax([],Acc) -> 
	Acc;
mymax([H|T],Acc) -> 
	mymax(T,max(Acc,H)).



test() ->
	3 = w2lists:prod([3]),
	90 = w2lists:prod([1,3,5,6]),
	54 = w2lists:mymax([1,23,4,54,23]),
	ok.

Excellent advice! thanks again!