Can I just point out that a colon doesn't mean "don't tracktrack past this point". It means "don't backtrack *into* the preceding repetition (to try a different number of matches), but skip back over it instead".

And to answer the original question, x??: and x*?: are exactly the same as x<0> (except that x??: returns a scalar-ish match object, rather than the list-ish one returned by x*?: and x<0>).

In reply to Re: Do nothing? or Do something important in a very obscure way? by TheDamian
in thread Do nothing? or Do something important in a very obscure way? by BrowserUk

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