learning erlang

-module(merge).
-compile(export_all).
-import(lists.filter).

qsort([]) -> [];
qsort([Head | Tail]) ->
   Pivot = Head,
   qsort(lists:filter(fun(X) -> X < Pivot end, Tail)) ++ [Pivot] ++ qsort(lists:filter(fun(X) -> X > Pivot end, Tail)).


length([], Total) -> Total;
length([_ | Tail], Total) ->
   length(Tail, Total + 1).
length(List) ->
   length(List, 0).

%% take takes the first N elements
takeT([], _) -> [];
takeT(_, 0)  -> [];
takeT([Head | Tail], N) ->
    [Head | takeT(Tail, N - 1)].


%% takeM takes every element after N and returns the list of elements after the Nth index
takeM([], _) -> [];
takeM([Head | Tail], N) ->
   if
      N >  0  -> takeM(Tail,  N - 1);
      N == 0 -> [Head | takeM(Tail, N)];
      true -> []
  end.


merge([]) -> [];
merge([Head]) -> [Head];
merge([Head | Tail]) ->
   Left   = qsort(takeT([Head | Tail], erlang:trunc(merge:length([Head | Tail])/2))),
   Right  = qsort(takeM([Head | Tail], erlang:trunc(merge:length([Head | Tail])/2))),
   Left ++ Right.



lol merge quicksort

That's nice, but please use some code tags please! (╬ ಠ益ಠ)


-module(merge).
-compile(export_all).
-import(lists.filter).

qsort([]) -> [];
qsort([Head | Tail]) ->
   Pivot = Head,
   qsort(lists:filter(fun(X) -> X < Pivot end, Tail)) ++ [Pivot] ++ qsort(lists:filter(fun(X) -> X > Pivot end, Tail)).


length([], Total) -> Total;
length([_ | Tail], Total) ->
   length(Tail, Total + 1).
length(List) ->
   length(List, 0).

%% take takes the first N elements
takeT([], _) -> [];
takeT(_, 0)  -> [];
takeT([Head | Tail], N) ->
    [Head | takeT(Tail, N - 1)].


%% takeM takes every element after N and returns the list of elements after the Nth index
takeM([], _) -> [];
takeM([Head | Tail], N) ->
   if
      N >  0  -> takeM(Tail,  N - 1);
      N == 0 -> [Head | takeM(Tail, N)];
      true -> []
  end.


merge([]) -> [];
merge([Head]) -> [Head];
merge([Head | Tail]) ->
   Left   = qsort(takeT([Head | Tail], erlang:trunc(merge:length([Head | Tail])/2))),
   Right  = qsort(takeM([Head | Tail], erlang:trunc(merge:length([Head | Tail])/2))),
   Left ++ Right.

Way to reinvent the wheel bro
Also, why did you name drop takeM?

>>4
Also, why did you name drop takeM?
ftfy

>>5
lol OCD

RMS's best propaganda has always been his hacking. So it is for all of us; to the rest of the world outside our little tribe, the excellence of our software is a *far* more persuasive argument for openness and freedom than any amount of highfalutin appeal to abstract principles. So the next time RMS, or anybody else, urges you to "talk about freedom", I urge you to reply "Shut up and show them the code."

Also, if you want to learn Erlang, focus on the actor model and using processes efficiently. Learn functional programming in general from Haskell.

<