Re^3: Combinations of lists, etc

[AnomalousMonk]

In general, meta-quoting for regexes (as used in split) can be done with quotemeta or with the  \Q ... \E intepolation escape sequences (see Quote and Quote-like Operators), which work for both double-quote and regex interpolation.

[LanX]

Are you sure this works with File::Glob 's meta characters sufficiently well?

[AnomalousMonk]

No. In fact, I hadn't even thought about the general case in which glob metacharacters may be included in the input string, i.e., the string to be permuted (if that's what you're referring to).

Ferinstance, consider the input string 'Prefix{u,v}2={w,x}:b,{y,z}:1,2'. An attempt to fix this up so that glob produces

Prefix{u,v}2={w,x}:b:1
Prefix{u,v}2={w,x}:{y,z}:1
Prefix{u,v}2={w,x}:b:2
Prefix{u,v}2={w,x}:{y,z}:2

shows that there's a problem with the  , metacharacter: I can't figure out how to metaquote it.

c:\@Work\Perl\monks\NorthernFox>perl -wMstrict -MData::Dump -le
"my @proto_globules = (
   'Prefix{u,v}2={w,x}:b,{y,z}:1,2',
   );
 ;;
 my $rx_comma_in_curlies = qr{ { .*? , .*? } }xms;
 ;;
 my $rx_globmeta = qr{ [\[\]{}*?~] }xms;
 ;;
 my %globize = ('=' => '={',  ':' => '}:{',  '' => '}');
 ;;
 for my $globule (@proto_globules) {
   print qq{A: '$globule'};
   $globule =~ s{ ($rx_comma_in_curlies) }
                { (my $r = $1) =~ s{,}{\\,}xmsg;  $r; }xmsge;
   $globule =~ s{ (?= $rx_globmeta) }{\\}xmsg;
   print qq{B: '$globule'};
   $globule =~ s{ ([=:] | \z) }
                { print qq{S: '$1'};  $globize{$1}; }xmsge;
   print qq{C: '$globule'};
   my @globs = glob $globule;
   dd 'DD:', \@globs;  print '';  next;
   }
"
A: 'Prefix{u,v}2={w,x}:b,{y,z}:1,2'
B: 'Prefix\{u\,v\}2=\{w\,x\}:b,\{y\,z\}:1,2'
S: '='
S: ':'
S: ':'
S: ''
C: 'Prefix\{u\,v\}2={\{w\,x\}}:{b,\{y\,z\}}:{1,2}'
(
  "DD:",
  [
    "Prefix{u\\,v}2={w\\:b:1",
    "Prefix{u\\,v}2={w\\:b:2",
    "Prefix{u\\,v}2={w\\:{y\\:1",
    "Prefix{u\\,v}2={w\\:{y\\:2",
    "Prefix{u\\,v}2={w\\:z}:1",
    "Prefix{u\\,v}2={w\\:z}:2",
    "Prefix{u\\,v}2=x}:b:1",
    "Prefix{u\\,v}2=x}:b:2",
    "Prefix{u\\,v}2=x}:{y\\:1",
    "Prefix{u\\,v}2=x}:{y\\:2",
    "Prefix{u\\,v}2=x}:z}:1",
    "Prefix{u\\,v}2=x}:z}:2",
  ],
)

The  \{u\,v\} isn't too bad, but wrapping a pair of  { } permuting curlies around  \{w\,x\} or  b,\{y\,z\} reveals that the comma is still "active":

    still active! -------+------------+
                         |            |
                         v            v
C: 'Prefix\{u\,v\}2={\{w\,x\}}:{b,\{y\,z\}}:{1,2}'
                    ^        ^ ^          ^
                    |        | |          |
 in added curlies --+--------+-+----------+

So unless someone can figure out how to metaquote the glob comma-in-curlies operator, it looks like a parser of some kind is the way to go in the general case.

[LanX]

thanks!

looks like a windows bug portability issue for me

  DB<54> x glob 'x{\{a\,b\}}y'
0  'x{a\\y'
1  'xb}y'
  DB<55> p "$^O, $]"
MSWin32, 5.024001

no such effect un linux or termux

  DB<1>  x glob 'x{\{a\,b\}}y'
0  'x{a,b}y'
  DB<2> p "$^O, $]"
linux, 5.018002
  DB<3>

> (if that's what you're referring to).

I was referring to the fact that quotemeta is meant for regexes, which have a differing set of meta-characters.

update

from File::Glob#NOTES

As a concession to user expectation, therefore, backslashes (under GLOB_QUOTE) only quote the glob metacharacters '[', ']', '{', '}', '-', '~' and backslash itself. All other backslashes are passed through unchanged.

OMG... oO