From: Kenichi Komiya <kom@...1.accsnet.ne.jp>
Date: 2001-01-23T01:44:17+09:00
Subject: [ruby-talk:9722] Re: Name of iterators for trees?


Hi,

From: "Agnot Tok" <agnottok@hotmail.com>
Subject: [ruby-talk:9716] Name of iterators for trees?
Date: Tue, 23 Jan 2001 00:08:04 +0900

> Hi,
> 
> Iterators is a nice concept and I'm trying to apply the idea to trees. 
> However, I'm not sure how to name things. Should "each" be a depth-first, 
> reversed-depth-first or even a breadth-first iterator? Should it be 
> parameterized so that the user can specify the node-visiting order? Anyone 
> seen any work/a good design on/for this? Whats a "natural" naming?
> 
> my_tree.each(:DEPTH_FIRST) {|node| ...}
> or
> my_tree.each_node_depth_first {|node| ...}

I think the later is more common.  ex. String#each and String#each_byte.

There is an alternative way.  You may find Okada-yun-Jun's
EnumDelegator in RAA useful.

quote from the document:

# What's enumdelegator?
#
# Enumdelegator is a library, to add Enumerable capability to a existing
# method, which takes block as argument (namely iterator!).
#
#
# In ruby, there are classes, which have several methods named
# 'each_*'. for exapmple, String have both 'each_line' and
# 'each_byte'.
#
# In such a class, I have a desire to apply Enumerable methods to
# these #methods, but I couldn't. 'each' is a only method, who is
# interface for Enumerable.

Regards,
Komiya.