[TxMt] regex question

[Paul Knight]

On Feb 21, 2006, at 2:42 AM, Xavier Noria wrote:

> On Feb 21, 2006, at 11:30, Oliver Taylor wrote:
>
>> I don't know where else to turn for help with regex,
>
> There's freenode#regex.
>
>> so I turn to you. Consider the following:
>>
>> ------------------------
>> ONCE
>> (twice)
>> Three times a lady.
>> Not as much as the Gambler.
>> (This sucks)
>> How would you know?
>> ------------------------
>>
>> How do I match the 2nd line but not the 5th?
>> How do I match the 6th, but not he 3rd?
>
> What is different in each case? The presence of ONCE exactly in the  
> line before?

Indeed, I'm uncertain what the logic behind the matches is supposed  
to be. Is the second line matched because of the sequence of cardinal  
numbers, a parenthetical following a line of all capital letters, a  
parenthetical with only one word, a parenthetical with no capitalized  
letters, a parenthetical followed by a statement... and so on.

>
>> P.S. Do you guys have any really good references for regex (aside  
>> from the manuel), where I can hunt down problems like this?
>
> You could read the Perl tutorials, there's some Perl there of  
> course, but just a minimum:
>
>     $ perldoc perlrequick
>     $ perldoc perlretut
>
> There's a handy quick reference as well (with some Perlisms):
>
>     $ perldoc perlreref
>
> I don't know whether TM supports the most "advanced" idioms, but in  
> any case it will help you to get started for sure.
>
> -- fxn

Textmate, in my understanding, uses the Oniguruma [1] regular  
expression library. The reference [2] summarizes the supported  
constructs and character classes.

There's also a section in the manual comparing the differences  
between Oniguruma and Perl's regex engine.

Paul Knight

[1] http://www.geocities.jp/kosako3/oniguruma/
[2] http://www.geocities.jp/kosako3/oniguruma/doc/RE.txt