base36.erl

-module(base36).
-export([encode/1]).

encode(Input)->
    encode(Input, "").

encode(Input, Encoded) ->
    if Input > 36 ->
	    E = lookup(Input rem 36),
	    encode(Input div 36,[E|Encoded]);
       true -> E = lookup(Input),
	       [E|Encoded]
     end.    

lookup(Input) ->
    Charset = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ",
    lookup(Charset, Input, 0).
lookup([H | T], Input, Index) ->
    if Input == Index -> H;
       true -> lookup(T, Input, Index + 1)
    end.

encode integers in base36