Observe:

$_="a1 a2 a3";
while(?a(\d)?g){ print $1; }
[download]

It prints "1", and thats all, just as you would expect. The ?? only matches once and then the loop fails. The ??g modifier has no affect. But observe the following:

$_="a1 a2 a3";
while(?a(\d)?g){ print $1; }
while(?a(\d)?g){ print $1; }
[download]

It prints "12". Repeating the ?? code causes it to match again, but from a different spot. Anyone want to explain this?

Update:
Apparently regular regexes do this also:

$_="a1 a2 a3 a4";
while(/a(\d)/g){ print $1; last; }
while(/a(\d)/g){ print $1; }
[download]

Actually prints "1234", not "11234", as you might expect. My question is, why does the second time the regex is typed being affected by the first time the regex is typed? They're two completely seperate regexen, at least as far as I can tell.

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