Erlang sorting

sorting.erl

-module(sorting).

-export([mergesort/1, quicksort/1]).

merge([], L) -> L;
merge(L, []) -> L;
merge(L1=[H1|T1], L2=[H2|T2]) ->
	if
		H1 =< H2 -> [H1 | merge(T1, L2)];
		true -> [H2 | merge(L1,T2)]
	end.

mergesort([]) -> [];
mergesort([H]) -> [H];
mergesort(List) when is_list(List) ->
	{L1,L2} = lists:split(length(List) div 2, List),
	merge(mergesort(L1), mergesort(L2)).

% ------------------------------------------------- %

partition([]) -> {[], [], []};
partition([H]) ->
	{[H], [], []};
partition([Pivot|T]) ->
	Less = [ X || X <- T, X =< Pivot],
	Greater = [ X || X <- T, X > Pivot],
	{Less, [Pivot], Greater}.

quicksort([]) -> [];
quicksort([H]) -> [H];
quicksort(List) when is_list(List) ->
	{L1, [Pivot], L2} = partition(List),
	quicksort(L1) ++ [Pivot] ++ quicksort(L2).