From: Brian Candler <b.candler@...>
Date: 2010-12-16T00:21:11+09:00
Subject: Re: Split a string at a certain character

Matt Slay wrote in post #968427:
> However, I've notice that the server console is spitting out this
> message below with every request hit that comes in:
>
> warning: nested repeat operator + and ? was replaced with '*':
> /\A((?:\d+)?(?:\.\d+)?)\s*([a-z]{1,2}\d+)\z/
>
> The whole process works fine, and but I am confused as to what this
> means.

\d+ means "a digit, one or more times"

(?: ... ) makes a non-capturing group

(?: ... )? means "this group 0 or 1 times"

So the part of your regexp where you have

(?:\d+)?

says "one or more digits, 0 or more times". Ruby is pointing out that 
this is a convoluted way of saying "0 or more digits", and is optimising 
it to:

\d*

(where '*' means 0 or more times)

-- 
Posted via http://www.ruby-forum.com/.