On 09/15/2018 07:32 PM, Larry Wall wrote:
On Sat, Sep 15, 2018 at 06:45:33PM -0700, ToddAndMargo wrote:
: Hi All,
:
: I have been doing a bunch with regex's lately.
: I just throw them out based on prior experience
: and they most all work now. I only sometimes have to
: ask for help. (The look forward () feature
: is sweet.)
:
: Anyway, I have been using regex switches without
: knowing why. So
:
: What is the difference between
:
: \N
That is a character that is not any of the valid \n characters.
: :\N
That is not a thing. That is a colon, which causes the previous thing
to not backtrack (if it would), followed by a \N (see above).
: <:\N>
That is not a thing. In fact, it's a syntax error.
: <<\:N>>
That also is not a thing. That is a left word boundary <<, followed by
\:, which matches a quote literally because it's backslashed, followed
by an N, which also matches literally, followed by the right word
boundary >>. As a pattern, it is impossible for the combination to match,
since, while >> can match after a literal N, a << cannot match before a colon.
: And why would I choose one over the other (what
: are they called out for)?
I would never choose any of them, apart from \N. Where are you getting
this craptastic list from?
Larry
Hi Larry,
Well. I will have to go through my question with a fine
toothed comb and create a keeper tutorial for what I
come up with. And in the process, I will no doubt trip
across a lot of stuff I got wrong.
It may be two weeks before I get back -- I have to finish
my company's federal taxes -- but I will get back with whagt I
come up with.
And to answer your question: I got some of this stuff
from
https://docs.perl6.org/language/regexes#index-entry-regex_%3C%3Aproperty%3E-Unicode_properties
some from context (what I have seen), and
Well, the rest of it from, shall we say pulled out of
my ear.
Into everyone's life a little humiliation must fall.
Thank you for all your help with this.
-T
