Beefy Boxes and Bandwidth Generously Provided by pair Networks
Perl Monk, Perl Meditation

Re: Remove comments between delimiters

by swiftone (Curate)
on Sep 20, 2002 at 13:24 UTC ( #199460=note: print w/replies, xml ) Need Help??

in reply to Remove comments between delimiters

First, do you realize that your <> regex may not work as intended if you have nested or broken pairs? For example: <This works>
<<This will break>>
<<As will this>

Second, I'm not sure I understand your question. Are you trying to remove /*This*/
Or turn it into //
Or are you just trying to get rid of *This*?

Assuming the latter, s/\*[^*]*\*//g should do what you want.

The trick is that in a matched pair (<>) you can use the presence of a starting tag (<) to stop a greedy match from eating the rest of your regexp. In an unmatched pair (*foo*) a greedy regexp will consume everything until the final matching element. So we switch to non-greedy matching with a dot star, or greedy without consuming our match (the [^*])

I hope that answers your question.

Update: Death to Dot Star! is an excellent discussion of greediness, the greedy dot-star, and why non-greediness isn't always the best solution.
Update2: Removed my non-greedy match that was in defiance of my own advice :)

Log In?

What's my password?
Create A New User
Node Status?
node history
Node Type: note [id://199460]
and all is quiet...

How do I use this? | Other CB clients
Other Users?
Others rifling through the Monastery: (6)
As of 2017-07-23 16:17 GMT
Find Nodes?
    Voting Booth?
    I came, I saw, I ...

    Results (347 votes). Check out past polls.