An alternative is the sledgehammer approach of retrying until there is nothing more:

1 while $s =~ s/,,/,0,/;

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At least in this case, it's not hard to see that this approach will need at most two runs to replace all occurrences properly. Other, more complex regular expressions might need more thought, especially when the strings grow long. Rescanning a string might be more expensive than picking up a bit before where you last left off.

In reply to Re: Regex to replace consecutive tokens by Corion
in thread Regex to replace consecutive tokens by {}think

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