$|++;my($a,$b,
       $c)=(0,sub{$a+=2;$a-2?$
    a%3?$|:$            a/3:$a},
  sub{my($                 a,$b,$c
 ,$d,$f)                    =(10,0,
 0,1,@_)                     ;sub{my
($e,$g);until($b&&$d&&($e=int($a/$b))
==int($c/$d)){$e=$f->();$g=$a;$a=$c;(
$c*=$e)+=$g;$g=$b;$b=$d;($d*=$e)+=$g}
$g=$a;$
 a=$b;($
 b*=-$e)
  +=$g;$g                     =$c;$c
   =$d;($d*=               -$e)+=$
      g;$e}});while(1){print$b->
           ();$b=$c->($b)}#e
[download]

Thanks to Anonymous Subroutines for inspiration.

Update: Thanks also to tachyon for formatting tips (Re: e with continued fractions).