* Xiangrong Fang (xrfang / hotmail.com) [28 Aug 2003 22:49]:

[...]
> 1. what is the use of nested modules? i.e., why?

Separation of code?

> 2. What is the meaning of the following code? especially
>    the "(?:" and "(?# 1:"?

>     (#{PATTERN::SCHEME}):                (?# 1: scheme)
>     (?:
>        (#{PATTERN::OPAQUE_PART})         (?# 2: opaque)

(?:...) and (?#...) are documented in the pickaxe.

Respectively they are 'cluster' (group without capturing),
and 'embedded comment'.


cheers,
-- 
Iain.