in reply to (XML::Parser) Finding and fixing a bug

I'm still struggling to understand what the original (buggy) code was trying to achieve. Was it to enable something like this to actually work:

use XML::Parser;

open CONFIG, ('config.xml') || die $!;

my $parser = XML::Parser->new(Style => 'Tree');

my $config = $parser->parse('CONFIG');

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If so, that doesn't seem to work even using the unpatched version of the module. Can anyone give a working example of providing a symbol name to the parse method? If the original code does not actually work as intended, then a patched version wouldn't need to worry about backwards compatibility.

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Re: Re: (XML::Parser) Finding and fixing a bug
by Juerd (Abbot) on Apr 21, 2003 at 23:19 UTC

    my $config = $parser->parse('CONFIG'); 

    my $config = $parser->parse(*CONFIG);

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    But that would better be checked with something like ref(\$arg) eq 'GLOB'.

    But... XML::Parser::Expat::parse allows strings to be used. In your try, it'll try to use XML::Parser::Expat::CONFIG. Things change if your symbolic reference contains ::: 

    my $config = $parser->parse('main::CONFIG');

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    It is unlikely that someone uses a string constant there, but it COULD be some $foo that is the result of whatever, which could in turn be some stringified version of *CONFIG. *CONFIG stringifies to *main::CONFIG, and with that * there it still works: 
    my $config = $parser->parse('*main::CONFIG');

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    I didn't want to break (stupid) code like this: 

    sub something_that_stringifies { "$_[0]" }
my $fh = something_that_stringifies *CONFIG;
my $config = $parser->parse($fh);

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    Juerd
- http://juerd.nl/
- spamcollector_perlmonks@juerd.nl (do not use).

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