On 4/9/07, Ian Tegebo <[EMAIL PROTECTED]> wrote:
On 4/9/07, Nikolai Weibull <[EMAIL PROTECTED]> wrote:
> ^ \{3\}[a-z][a-z ]*[a-z]$
I hope nobody minds if I take this opportunity to ask a question about
vim's pattern matching.
After reading |pattern| I wonder if the following is more efficient:
syn match manSubHeading '^ \{3\}\l\l\?\l$'
Yes, and it may be more correct as well, at least in the first and
last instance. However, the second part may also contain a space, so
\l isn't correct there; and I don't know where you get that \? from.
This is the correct pattern:
^ \{3}\l[[:alpha:] ]*\l$
(I also noticed that the apparently accepted "\{m\}" is being used in
this file instead of the documented "\{m}")
One can of course ask oneself if a subsection heading must consist of
at least two letters. I'm guessing that the intent was to force the
line to end with a non-space:
^ \{3}\l\%([[:alpha:] ]*\l\)\=$
In fact, I'd prefer it be written as
^ \{3}\a\%([[:alpha:] ]*\a\)\=$
as 'syn case ignore' is on, \l and \a will be the same. However, \a
meshes better with [:alpha:] and may, depending on how all this is
implemented, be a miniscule amount faster.
Taken from |pattern|:
- Matching with a collection can be slow, because each character in
the text has to be compared with each character in the collection.
Use one of the other atoms above when possible. Example: "\d" is
much faster than "[0-9]" and matches the same characters
Do people find this to make a different for moderate file sizes, e.g.
the man page for 'less' being ~2000 lines?
Probably not.
nikolai
