Beefy Boxes and Bandwidth Generously Provided by pair Networks
go ahead... be a heretic

Re: Evaluating code in a regex at runtime: (??{...})

by dave_the_m (Prior)
on Jan 28, 2013 at 01:12 UTC ( #1015606=note: print w/ replies, xml ) Need Help??

in reply to Evaluating code in a regex at runtime: (??{...})

When a pattern is compiled, all the captures are allocated fixed indices: so for example when the following pattern is compiled, the indices shown are assigned.

/(....)...(...)...(??{foo()})....(...)/ ^ ^ ^ 1 2 3
In particular, the last capture is index number 3.

Each time the pattern is run, foo() might return a string or qr// which has a different number of captures; and which might recursively also include /(??{...})/ and further nested captures. This would make it nearly impossible to guess how to refer to the final capture in the outer pattern, unless we just always call it $3.


Comment on Re: Evaluating code in a regex at runtime: (??{...})
Download Code

Log In?

What's my password?
Create A New User
Node Status?
node history
Node Type: note [id://1015606]
and the web crawler heard nothing...

How do I use this? | Other CB clients
Other Users?
Others chanting in the Monastery: (3)
As of 2015-11-25 03:54 GMT
Find Nodes?
    Voting Booth?

    What would be the most significant thing to happen if a rope (or wire) tied the Earth and the Moon together?

    Results (670 votes), past polls