in reply to Re: Replacing substrings with links
in thread Replacing substrings with links

If more than one iteration is needed, you can use a loop with a "change" flag: 
my $change = 1;
while ($change) {
    $change = 0;
    $change ||= s/^($pattern)/$h_orig->{$1}/g
        for values %copy;
}

[download]

map{substr$_->[0],$_->[1]||0,1}[\*||{},3],[[]],[ref qr-1,-,-1],[{}],[sub{}^*ARGV,3]

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Re^3: Replacing substrings with links
by LanX (Saint) on Feb 06, 2022 at 14:59 UTC
    I think it's easier and more efficient to switch the loops.

    for (values %copy) {
    1 while                              # repeat till no replacement 
+left
        s/^($pattern)/$h_orig->{$1}/g; 
}

    [download]

    But I have trouble to come up with a test case covering the complicated implications. ( Update Anyone? ) 

    use strict;
use warnings;
use Data::Dump qw/pp dd/;

my $h_orig =
  {
  '/a/b/c/dt/data/SUSE/tool/0.9.0' => '/a/b/c/dt/tools/SUSE/tool/0.9.0
+',
  '/nfs/us' => '/usr/bin',
  '/a/b/c' => '/nfs/us'
  };


my $pattern = join "|", map quotemeta, keys %$h_orig;

my %copy = %$h_orig;

for (values %copy) {
    1 while s/^($pattern)/$h_orig->{$1}/g; 
}

pp $h_orig, \%copy;

    [download]

    -*- mode: compilation; default-directory: "d:/tmp/pm/" -*-
Compilation started at Sun Feb  6 15:59:06

C:/Strawberry/perl/bin\perl.exe -w d:/tmp/pm/replace_pat2.pl 
(
  {
    "/a/b/c" => "/nfs/us",
    "/a/b/c/dt/data/SUSE/tool/0.9.0" => "/a/b/c/dt/tools/SUSE/tool/0.9
+.0",
    "/nfs/us" => "/usr/bin",
  },
  {
    "/a/b/c" => "/usr/bin",
    "/a/b/c/dt/data/SUSE/tool/0.9.0" => "/usr/bin/dt/tools/SUSE/tool/0
+.9.0",
    "/nfs/us" => "/usr/bin",
  },
)

Compilation finished at Sun Feb  6 15:59:06

    [download]

    Cheers Rolf
    (addicted to the Perl Programming Language :)
    Wikisyntax for the Monastery

[reply]
[d/l]
[select]
      I tested my previous code with 
      my $h_orig = {
    '/a/b/c/dt/data/SUSE/tool/0.9.0' => '/a/b/c/dt/tools/SUSE/tool/0.9
+.0',
    '/nfs/us/tools/SUSE'             => '/usr/bin',
    '/a/b/c'                         => '/p',
    '/p/dt'                          => '/nfs/us'};

      [download]

      Your code gives the same result for the input.

      Update: Ordering is important. I have no idea what the expected output of 

      my $h_orig = { '/a' => '/b/c',
               '/b/c' => '/a',
               };

      [download]
      is.

      map{substr$_->[0],$_->[1]||0,1}[\*||{},3],[[]],[ref qr-1,-,-1],[{}],[sub{}^*ARGV,3]
[reply]
[d/l]
[select]
        I think the results with this test case really depend on the randomization of the hash.

        (testing with hash order is tricky, I wonder if there is a general solution for that)

        update

        tho /p/dt is not a "absolute path" if /p is a link. 🤷🏽

        Cheers Rolf
        (addicted to the Perl Programming Language :)
        Wikisyntax for the Monastery

[reply]
[d/l]
[select]
Re^3: Replacing substrings with links
by LanX (Saint) on Feb 05, 2022 at 20:46 UTC
    I really have a problem with the whole fuzzy concept, otherwise I would try to work with sorting first.

    Now apparently there are values which include their own key, otherwise this exclusion criteria wouldn't be needed.

    But what kind of sane link is self referential?

    Cheers Rolf
    (addicted to the Perl Programming Language :)
    Wikisyntax for the Monastery

[reply]

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