I'm not too shabby at REGEXes but this one isn't behaving as I'd expect.

I want to remove all redundant numbers and their separators in a string (the numbers are always 2 digits) like:

12-12 -> 12
12-12-12 -> 12
12-13-12-13 -> 12-13
12-12-13-13- -> 12-13
12-13-13-14 -> 12-13-14

and so on.

I figured this was a good start:

s/(\d\d)(-\d\d)*?(-\1)/$1$2/g;

but although it DOES remove a number, it (to me, unexpectedly) only removes one. I read that as:
FIND A NUMBER
LOOK FOR other seperator / numbers, miminally
find a seperator and matching number to the first one
replace it with the initial number and the minuimally matched stuff
repeat

I get this:
12-14-12-12 -> 12-14-12

I realize I could put this in some sort of while () loop until it no longer matches but that seems like it should be unnecessary.

I know I need a non-consumiung match on the (-\d\d)*? part so I tried: ?=(-\d\d)*? instead, but then it never matched ANYTHING....

Wise ones please enlighten me? Perhaps there is a switch that tells the regex to go back to ^ after each substitution?

Thank-You.

In reply to How can I reduce this with a REGEX? by misterperl

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