PyPCASTL

enclosure = function()
{
    i = 0
    return(function()
	   {
	       i = i + 1
	       print(i)
	   }
    )
}

closure1 = enclosure()
closure1()
closure1()
closure1()
closure1()

closure2 = enclosure()
closure2()
closure2()
closure2()
closure2()
closure2()

source.pl

python pcastl.py source.pl

いいね。

未実装はmknode,rmnode,parent,childsetまぁつまり構文木を弄る所が全くノータッチです。