As I don’t have my copy of Mastering Regular Expressions at home, and
I’m not that good with them (yet 
I question for the RegEx gurus:
if I want to match “dec” at the beginning of a string how would I do
that:
/\Adec/
matches on string “decimal” and “dec” basically I want ‘dec’ not
followed by [A-Za-z0-9_-] but anything else is ok (including ‘dec’ being
the entire string)
Thanks in advance
-rich
sorry for answering my own question…just found
/\Adec(?![a-zA-Z0-9_])/
-rich
-----Original Message-----
From: Rich Kilmer [mailto:rich@infoether.com]
Sent: Saturday, September 07, 2002 5:15 PM
To: ruby-talk ML
Subject: Regular expression questionAs I don’t have my copy of Mastering Regular Expressions at
home, and I’m not that good with them (yetI question for
the RegEx gurus:if I want to match “dec” at the beginning of a string how would I do
that:/\Adec/
matches on string “decimal” and “dec” basically I want ‘dec’
not followed by [A-Za-z0-9_-] but anything else is ok
(including ‘dec’ being the entire string)Thanks in advance
-rich
Hi –
As I don’t have my copy of Mastering Regular Expressions at home, and
I’m not that good with them (yet
Answering questions addressed to gurus is usually a guarantee that
I’ll get it wrong, but I’ll try anyway
if I want to match “dec” at the beginning of a string how would I do
that:/\Adec/
matches on string “decimal” and “dec” basically I want ‘dec’ not
followed by [A-Za-z0-9_-] but anything else is ok (including ‘dec’ being
the entire string)
You want a negative lookahead:
/\Adec(?![A-Za-z0-9_-])/
You can shorten it to:
/\Adec(?![\w-])/
the difference being that \w is locale-dependent (which is quite
likely good, if you want to avoid all alphanumeric characters).
David
On Sun, 8 Sep 2002, Rich Kilmer wrote:
–
David Alan Black | Register for RubyConf 2002!
home: dblack@candle.superlink.net | November 1-3
work: blackdav@shu.edu | Seattle, WA, USA
Web: http://pirate.shu.edu/~blackdav | http://www.rubyconf.com
Actually I did not need the - so the /\Adec(?[\w])/ worked great.
Thank you my RegEx guru 
-rich
-----Original Message-----
From: dblack@candle.superlink.net
[mailto:dblack@candle.superlink.net]
Sent: Saturday, September 07, 2002 5:24 PM
To: ruby-talk ML
Subject: Re: Regular expression questionHi –
On Sun, 8 Sep 2002, Rich Kilmer wrote:
As I don’t have my copy of Mastering Regular Expressions at
home, and
I’m not that good with them (yetAnswering questions addressed to gurus is usually a guarantee
that I’ll get it wrong, but I’ll try anywayif I want to match “dec” at the beginning of a string how would I do
that:/\Adec/
matches on string “decimal” and “dec” basically I want ‘dec’ not
followed by [A-Za-z0-9_-] but anything else is ok (including ‘dec’
being the entire string)You want a negative lookahead:
/\Adec(?![A-Za-z0-9_-])/
You can shorten it to:
/\Adec(?![\w-])/
the difference being that \w is locale-dependent (which is
quite likely good, if you want to avoid all alphanumeric characters).David
–
David Alan Black | Register for RubyConf 2002!
home: dblack@candle.superlink.net | November 1-3
work: blackdav@shu.edu | Seattle, WA, USA
Web: http://pirate.shu.edu/~blackdav | http://www.rubyconf.com
Hi –
On Sun, 8 Sep 2002, Rich Kilmer wrote:
Actually I did not need the - so the /\Adec(?[\w])/ worked great.
In that case you don’t need the […], because \w creates an implicit
character class of its own. (But you do need to restore the ‘!’
/\Adec(?!\w)/
David
–
David Alan Black | Register for RubyConf 2002!
home: dblack@candle.superlink.net | November 1-3
work: blackdav@shu.edu | Seattle, WA, USA
Web: http://pirate.shu.edu/~blackdav | http://www.rubyconf.com
dblack@candle.superlink.net writes:
Actually I did not need the - so the /\Adec(?[\w])/ worked great.
In that case you don’t need the […], because \w creates an implicit
character class of its own. (But you do need to restore the ‘!’/\Adec(?!\w)/
I think you could write this
/\Adec\b/
where \b matches the “word boundary” after “dec”.
/Johan Holmberg
On Sun, 8 Sep 2002, Rich Kilmer wrote:
Switched to that…it works great.
Thanks,
rich
-----Original Message-----
From: Johan Holmberg [mailto:holmberg@iar.se]
Sent: Sunday, September 08, 2002 3:10 PM
To: ruby-talk ML
Subject: Re: Regular expression questiondblack@candle.superlink.net writes:
On Sun, 8 Sep 2002, Rich Kilmer wrote:
Actually I did not need the - so the /\Adec(?[\w])/ worked great.
In that case you don’t need the […], because \w creates
an implicit
character class of its own. (But you do need to restore
the ‘!’/\Adec(?!\w)/
I think you could write this
/\Adec\b/where \b matches the “word boundary” after “dec”.
/Johan Holmberg