On Wednesday, February 24, 2016 at 12:00:22 PM UTC-6, Paul wrote:
> I have a text file and I would like to compose a regular expression
> that matches lines containing stringB but not preceded by a line
> containing string A. I thought one of these might do it:
>
> \(stringA.*\n\)\@<!.*stringB
> \(stringA.*\n\)\@<!\(.*stringB\)
>
> The \@<! was *intended* to ensure a non-match with stringA in the
> preceding line. However, they highlight the same lines that are
> highlighted by the opposite regular expressions:
>
> \(stringA.*\n\)\@<=.*stringB
> \(stringA.*\n\)\@<=\(.*stringB\)
>
> With a little pondering, it is obvious why. The first .* matches any
> set of characters, so even if stringA exists in the preceding line,
> you can always find some portion of the line that doesn't match
> \(stringA.*\n\).
>
> Is there a way to achieve the search described in above?
Move the newline outside of your negative look-behind, then start the match using \zs after the newline if you only want to match the 2nd line.
Make it work on the 1st line as well by temporarily inserting a blank line at the top, or checking it manually, if needed.
Here's what I mean, if my description isn't clear: \(stringA.*\)\@<!\n\zs.*stringB
--
--
You received this message from the "vim_use" maillist.
Do not top-post! Type your reply below the text you are replying to.
For more information, visit http://www.vim.org/maillist.php
---
You received this message because you are subscribed to the Google Groups "vim_use" group.
To unsubscribe from this group and stop receiving emails from it, send an email to vim_use+unsubscribe@googlegroups.com.
For more options, visit https://groups.google.com/d/optout.
No comments:
Post a Comment