BTW, this looks like a copy & paste of some code from perlre.

When you add a use re 'debug'; to your code (or use re Debug => 'EXECUTE';), it outputs this:

Matching REx "(.*?)(\d*)" against "I have 2 numbers: 53147"
   0 <> <I have 2 n>         |   0| 1:OPEN1(3)
   0 <> <I have 2 n>         |   0| 3:MINMOD(4)
   0 <> <I have 2 n>         |   0| 4:STAR(6)
   0 <> <I have 2 n>         |   1|  6:CLOSE1(8)
   0 <> <I have 2 n>         |   1|  8:OPEN2(10)
   0 <> <I have 2 n>         |   1|  10:STAR(12)
                             |   1|  POSIXU[\d] can match 0 times out 
+of 2147483647...
   0 <> <I have 2 n>         |   2|   12:CLOSE2(14)
   0 <> <I have 2 n>         |   2|   14:END(0)
Match successful!
(.*?)(\d*)   <> <>

[download]

Since the non-greedy modifier ? causes .* to match the minimum number of times possible, which is zero, followed by zero or more digits (\d*), the regex succeeds having matched zero characters.

In reply to Re: Regex Minimal Quantifiers by haukex
in thread Regex Minimal Quantifiers by pr33

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