Definition Group(?(DEFINE)(?<cons>\b(?:
(?<x>\d*)
(?:(?<a0>0)|(?<a1>1)|(?<a2>2)|(?<a3>3)|(?<a4>4)
|(?<a5>5)|(?<a6>6)|(?<a7>7)|(?<a8>8))
(?<y>
,\g{x}
(?(a0)1)(?(a1)2)(?(a2)3)(?(a3)4)(?(a4)5)
(?(a5)6)(?(a6)7)(?(a7)8)(?(a8)9)
| 9 (?&y) 0
)
# handle the 999 => 1000 case separately
| (?<z> 9,10 | 9(?&z)0 )
)\b)) Group cons(?<cons>\b(?:
(?<x>\d*)
(?:(?<a0>0)|(?<a1>1)|(?<a2>2)|(?<a3>3)|(?<a4>4)
|(?<a5>5)|(?<a6>6)|(?<a7>7)|(?<a8>8))
(?<y>
,\g{x}
(?(a0)1)(?(a1)2)(?(a2)3)(?(a3)4)(?(a4)5)
(?(a5)6)(?(a6)7)(?(a7)8)(?(a8)9)
| 9 (?&y) 0
)
# handle the 999 => 1000 case separately
| (?<z> 9,10 | 9(?&z)0 )
)\b) \ban ASCII word boundary
Non-Capturing Group(?:
(?<x>\d*)
(?:(?<a0>0)|(?<a1>1)|(?<a2>2)|(?<a3>3)|(?<a4>4)
|(?<a5>5)|(?<a6>6)|(?<a7>7)|(?<a8>8))
(?<y>
,\g{x}
(?(a0)1)(?(a1)2)(?(a2)3)(?(a3)4)(?(a4)5)
(?(a5)6)(?(a6)7)(?(a7)8)(?(a8)9)
| 9 (?&y) 0
)
# handle the 999 => 1000 case separately
| (?<z> 9,10 | 9(?&z)0 )
) 1st Alternative
(?<x>\d*)
(?:(?<a0>0)|(?<a1>1)|(?<a2>2)|(?<a3>3)|(?<a4>4)
|(?<a5>5)|(?<a6>6)|(?<a7>7)|(?<a8>8))
(?<y>
,\g{x}
(?(a0)1)(?(a1)2)(?(a2)3)(?(a3)4)(?(a4)5)
(?(a5)6)(?(a6)7)(?(a7)8)(?(a8)9)
| 9 (?&y) 0
)
# handle the 999 => 1000 case separately
\d*a digit, repeated any number of times
Non-Capturing Group(?:(?<a0>0)|(?<a1>1)|(?<a2>2)|(?<a3>3)|(?<a4>4)
|(?<a5>5)|(?<a6>6)|(?<a7>7)|(?<a8>8)) 0the literal 0 (4810 / 608 / 3016)
1the literal 1 (4910 / 618 / 3116)
2the literal 2 (5010 / 628 / 3216)
3the literal 3 (5110 / 638 / 3316)
4the literal 4 (5210 / 648 / 3416)
5the literal 5 (5310 / 658 / 3516)
6the literal 6 (5410 / 668 / 3616)
7the literal 7 (5510 / 678 / 3716)
8the literal 8 (5610 / 708 / 3816)
Group y(?<y>
,\g{x}
(?(a0)1)(?(a1)2)(?(a2)3)(?(a3)4)(?(a4)5)
(?(a5)6)(?(a6)7)(?(a7)8)(?(a8)9)
| 9 (?&y) 0
) 1st Alternative
,\g{x}
(?(a0)1)(?(a1)2)(?(a2)3)(?(a3)4)(?(a4)5)
(?(a5)6)(?(a6)7)(?(a7)8)(?(a8)9)
2nd Alternative 9 (?&y) 0
Comment: handle the 999 => 1000 case separately
2nd Alternative (?<z> 9,10 | 9(?&z)0 )
\ban ASCII word boundary
Comment: list of two or more consecutive integers
Positive Lookahead(?=(?&cons)) \d+a digit, repeated at least once
Non-Capturing Group(?:,(?=(?&cons))\d+)* \d+a digit, repeated at least once
g modifier: global. Finds all matches instead of stopping after the first
x modifier: extended. Ignores unescaped whitespace and comments outside character classes