Re^2: Unnesting deeply nested HTML elements (Deep recursion on subroutine "HTML::Element::delete")

Thanks. I've tried adding the no warnings 'recursion'; to both the example script above and to the real script (there in the smallest lexical scope available). It does not suppress the warnings in either case.

I wonder if there would be a way to simply collect and not print the warnings, perhaps with an eval. However, the attempt below still prints the same warnings as the original example script above.

#!/usr/bin/perl

use HTML::TreeBuilder::XPath -weak;

use strict;
use warnings;

my $ent = HTML::TreeBuilder::XPath->new;
$ent->parse_file(\*DATA);

eval {
    no warnings 'recursion';
    $ent->delete;
};

if ($@) {
    print "FOO\n";
}    

exit(0);

__DATA__
<html>
<head>
<title>foo bar</title>
</head>
<body>
foo
<br />
<center>
<center>
<center>
<center>
<center>
<center>
<center>
<center>
<center>
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<center>
<strong>bar</strong>
<br />
<center>(baz)</center>
</center>
</center>
</center>
</center>
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</center>
</center>
</body>
</html>
[download]

Comment on Re^2: Unnesting deeply nested HTML elements (Deep recursion on subroutine "HTML::Element::delete") Select or Download Code

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Re^3: Unnesting deeply nested HTML elements (Deep recursion on subroutine "HTML::Element::delete") by hv (Prior) on Sep 20, 2022 at 03:23 UTC
Yeah, warnings are lexically scoped, so turning them off in one place only suppresses them if that's where they are generated. In this case you need to get a bit more invasive: catch all warnings for the duration of the call, and rethrow all but the one you want to avoid: `{ local $SIG{__WARN__} = sub { warn @_ unless $_[0] =~ /^Deep recursion/; }; $ent->delete; }` [download] Note that it is safe to warn inside the warnings handler - the handler is suppressed while it is being called.	[reply] [d/l]

Replies are listed 'Best First'.

Re^3: Unnesting deeply nested HTML elements (Deep recursion on subroutine "HTML::Element::delete")
by hv (Prior) on Sep 20, 2022 at 03:23 UTC

Yeah, warnings are lexically scoped, so turning them off in one place only suppresses them if that's where they are generated.

In this case you need to get a bit more invasive: catch all warnings for the duration of the call, and rethrow all but the one you want to avoid:

{
  local $SIG{__WARN__} = sub {
    warn @_ unless $_[0] =~ /^Deep recursion/;
  };
  $ent->delete;
}
[download]

Note that it is safe to warn inside the warnings handler - the handler is suppressed while it is being called.

[reply]
[d/l]