Okay, this one has got me totally baffled. Basically, I have a regular expression that is slurping up more data than it rightly should. I really can't see anything I'm doing wrong and the results are totally unexpected, though the problem seems to be related to having \\? in the RE. It's hard to describe so I'll just go straight into the code...

Using this data:

$_ = 'foo\$bar';

This tokenizing code snippet: 

{
    if(m/\G(\\?\$\w+)/gc or m/\G(\w+)/gc) {
        print "token: '$1'\n";
        redo;
    }
}

[download]

Produces the following output:

token: '\$bar'

That is, it immediately matches '\$bar' and 'foo' gets skipped over (though it should be matched first by the second RE). If the \\? is changed to \\ in the first RE, or if the input is changed to 'foo$bar', then the 'foo' is matched correctly by the second RE. Unfortunately, neither of those is the logic I wanted.

Also, it doesn't seem to be the exact \\?, since it still matches incorrectly if I change it to (?:\\)?.

I really hope someone can give me a hint as to what is causing this strange behavior. TIA

(This is perl, version 5.005_03 built for i386-linux)

bbfu
Seasons don't fear The Reaper.
Nor do the wind, the sun, and the rain.
We can be like they are.

In reply to RE prollem: \G, \\? and disappearing data by bbfu

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