*SKIP*
I've looked thru "man perlop", specifically the section "Quote and
Quote-like Operators". It defines what Perl does with many sequences
(\n, \cX, \u, et cetera), but I don't see where it says anything about
"For any sequence not described above". Am I overlooking it?
Probably -- not. May be -- not yet.
If not, do you think I should ding my cow-order for the construct and
ask him to change it to
Well, perlrebackslash suggests this reasoning:
The rules determining what it is are quite simple: if the
character following the backslash is an ASCII punctuation
(non-word) character (that is,
+ anything that is not a letter,
+ digit, or underscore), then the backslash just takes away any
+ special meaning of the character following it.
Note mentioning underscore.
+ If the character following the backslash is an ASCII letter or
+ an ASCII digit, then the sequence may be special;
Now underscore is omitted.
if so, it's listed below.
+ A few letters have not been used yet, so escaping them with a
+ backslash doesn't change them to be special.
Right, ASCII doesn't have that many non-words Perl needs.
A future version of Perl may assign a special meaning to them,
so if you have warnings turned on, Perl issues a warning if you
use such a sequence. [1].
It is however guaranteed that backslash or escape sequences
never have a punctuation character following the backslash, not
now, and not in a future version of Perl 5. So it is safe to put
a backslash in front of a non-word character.
So, backslash takes away from non-words and gives to words. Surely,
underscore is neither alpha nor digit. But it still stands for word
anyway.
*CUT*
p.s. perlrebacklash seems irrelevant, right?
This document describes all backslash and escape sequences. After
explaining the role of the backslash, it lists all the sequences that
have a special meaning in Perl regular expressions (in alphabetical
order), then describes each of them.
Or perl*re*backslash is just misleading?
Most sequences are described in detail in different documents; the
primary purpose of this document is to have a quick reference guide
describing all backslash and escape sequences.
p.p.s. My bet is your reasons (whatever those could be) will all fall
dead.