Front page | perl.perl5.porters |
Postings from November 2009
2009/11/1 Tom Christiansen <tchrist@perl.com>:
> In-Reply-To: Message from Aristotle Pagaltzis <pagaltzis@gmx.de>
> of "Sun, 01 Nov 2009 04:11:30 BST." <20091101031130.GA5708@klangraum.plasmasturm.org>
>
>>* George Greer <perl@greerga.m-l.org> [2009-10-31 22:50]:
>>> After all the pains, it looks less painful if hashes
>>> subscripted with a different character
>
>> Not just hashes. Curlies in Perl source can have something like
>> 7 different meanings (if memory serves) depending on context.
>
> Just seven, you say? 'Pends how you count 'em, but I'm
> afraid seven's just a wee bit on the conservative side...
>
> 0. NOTHING:
> $i++; # } don't look at {this} here {
> / foo (?# silly }{ brackets ) bar /x
>
> 1. LITERAL:
> print "This {STU}{FF} means what it means!\n";
> m/foo\{nuff}/;
> #line 1066 "waysilly{file}name"
> =pod
> this is an em{pod}ded literal
> =cut
> __END__
> prithee what is this { matter } here?
>
> 2. HEADED BLOCK:
> if/do/eval/sub/etc { ... }
>
> 3. PROPER LOOP:
> while/foreach/etc { }
> { } # bare block for last/redo or scoping
>
> 4. HASH SUBSCRIPT:
> $h{string}
> $hr->{string}
>
> 5. ANON HASH ALLOCATOR:
> $new = { LIST };
>
> 6. DEREF ISOLATION:
> @{ fn(x) }[0,0,1,-1]
>
> 7. VARIABLE ISOLATION:
> print "Let's go to ${name}'s place.\n";
> ${^PREMATCH}
>
> 8. NAME OF A DISTINCT main'VARIABLE:
> $} = "whacked";
>
> 9. PYOQ DELIMS:
> qq{....}
> m{foo|bar}x
> q{.{ ... } ...} # 9 + 1
> ($rot13ed = $it) =~ y{a-zA-Z}{n-za-mN-ZA-M}
>
> 10. REGEX QUANTIFICATION: {m,n} {m.n}? {m.n}+
> m/ ( (?:foo|bar){4,9}? ) /x
>
> 11. REGEX NAME-GROUPED STUFF:
> m/ \x{DEADBEEF} /x
> m/ \p{Digit} /x
> m/ \g{-1} /x
> m/ \g{NAMEDREF} /x
>
> 12. FORMAT VALUE-LIST GROUPING:
> format =
> This @<<<<< is aligned to @>>>>
> {
> some_really_long_expression_that_returns_a_scalar,
> and_another_aligned_thingie
> }
> .
>
> 13. ARBITRARY STRING GENERATION:
> print for <{big,little}-{men,women,children}>; # 6 strings
>
> 14. EXISTENT FILENAME EXPANSION: (paths must -e)
> print for </{,usr{,/local}}/{{s,}bin}/*perl*>;
>
> 15. INDIRECT FILEHANDLE vs INDIRECT FILEGLOB:
> $ perl -e '$in = "STDIN"; print scalar <$in>' < /etc/motd
> OpenBSD 4.4 (GENERIC) #0: Tue Oct 21 10:02:18 MDT 2008
> $ perl -le '$in = "/etc/*"; print scalar <${in}>' < /etc/motd
> /etc/adduser.conf
IMO, \x{...} deserves its own category as it applies in more places
than just strings.
Yves
--
perl -Mre=debug -e "/just|another|perl|hacker/"
Thread Previous
|
Thread Next