This didn't seem to fit the description of a SoPW, so I'll ask here and accept the gods judgement if they choose to move it.

I was reading Exegesis5 and found this line:

Please note the presence of ':' colons following the regexes below, and the context in which this question was asked.

• Likewise, x*?: and x??: are arcane ways of matching exactly zero repetitions of x.

And couldn't make up mind which of the following this meant:

• Don't even bother trying to match an 'x' at this point.
• Fail if there is an 'x' at this point.

Opinions?

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What's this about a "crooked mitre"? I'm good at woodwork!

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