Regular expression mismatch?

ruby-talk
1

Good point. Anyone who has worked with regexes in the various languages can
attest to subtle (but far-reaching) differences between them. I recall the
first time I picked up the "Mastering Regular Expressions" book. A veritable
Bible for the beasties...

···

-----Original Message-----
From: David A. Black [mailto:dblack@wobblini.net]
Sent: Thursday, April 07, 2005 9:09 AM
To: ruby-talk@ruby-lang.org
Subject: Re: Regular expression mismatch ?

Hi --

On Thu, 7 Apr 2005, Han Holl wrote:

On Apr 7, 2005 12:34 PM, David A. Black >> The /m suffix means that \n is included in . (dot). >> > Yes, looked it up in the Pickaxe, and indeed that's what it says.

This is from man perlre:
      m Treat string as multiple lines. That is, change "^" and "$"
   from matching the start or end of the string to matching then
   start or end of any line anywhere within the string.

This should go on the page I've seen somewhere with gotchas. Perl RE
is quite widespread, and when ruby deviates from it it's easy to trip
up.

Not if you use Ruby more and more :slight_smile:

David

--
David A. Black
dblack@wobblini.net

2

Hi --

···

On Thu, 7 Apr 2005, Kujawa, Greg wrote:

-----Original Message-----
From: David A. Black [mailto:dblack@wobblini.net]
Sent: Thursday, April 07, 2005 9:09 AM
To: ruby-talk@ruby-lang.org
Subject: Re: Regular expression mismatch ?

Hi --

On Thu, 7 Apr 2005, Han Holl wrote:

On Apr 7, 2005 12:34 PM, David A. Black >>> The /m suffix means that \n is included in . (dot). >>> >> Yes, looked it up in the Pickaxe, and indeed that's what it says.

This is from man perlre:
      m Treat string as multiple lines. That is, change "^" and "$"
   from matching the start or end of the string to matching then
   start or end of any line anywhere within the string.

This should go on the page I've seen somewhere with gotchas. Perl RE
is quite widespread, and when ruby deviates from it it's easy to trip
up.

Not if you use Ruby more and more :slight_smile:
Good point. Anyone who has worked with regexes in the various languages can
attest to subtle (but far-reaching) differences between them. I recall the
first time I picked up the "Mastering Regular Expressions" book. A veritable
Bible for the beasties...

That's the thing... for better or worse, there's no single model for
how regexes work. Some things are more universal than others, but I
don't think there's any shortcut to adapting to whatever incarnation
of them one is using at a given time.

David

--
David A. Black
dblack@wobblini.net