Path: csiph.com!x330-a1.tempe.blueboxinc.net!usenet.pasdenom.info!goblin2!goblin.stu.neva.ru!newsfeed1.swip.net!uio.no!nntp.uib.no!svn.schaathun.net!not-for-mail From: Hans Georg Schaathun Newsgroups: comp.lang.python,comp.lang.lisp Subject: Re: English Idiom in Unix: Directory Recursively Followup-To: comp.lang.python Date: Wed, 18 May 2011 19:39:53 +0100 Organization: University of Bergen Lines: 26 Message-ID: References: <87aaekoab7.fsf@kuiper.lan.informatimago.com> NNTP-Posting-Host: vannskorpion.bccs.uib.no Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Trace: toralf.uib.no 1305743212 18209 129.177.20.20 (18 May 2011 18:26:52 GMT) X-Complaints-To: abuse@uib.no NNTP-Posting-Date: 18 May 2011 18:26:52 GMT User-Agent: slrn/pre1.0.0-18 (Linux) Xref: x330-a1.tempe.blueboxinc.net comp.lang.python:5723 comp.lang.lisp:3521 ["Followup-To:" header set to comp.lang.python.] On Wed, 18 May 2011 20:20:01 +0200, Raymond Wiker wrote: : I don't think anybody mentioned *binary* trees. The context was : directory traversal, in which case you would have nodes with an : arbitrary (almost) number of children. If we are being specific, then directory trees do have parent pointers. My point was really that «standard tree representations» is not a well-defined concept, and having parent pointers is as standard as not having them. : Except that the chain of parent pointers *would* constitue a : stack. In the sense that the tree itself is a stack, yes. But if we consider the tree (or one of its branches) to be a stack, then the original claim becomes a tautology. But you do have a point. Keeping a stack of nodes on the path back to root is a great deal simpler and cheaper than a call stack, and not really a significant expense in context. -- :-- Hans Georg