21.2.1 erroneous production?

[isiahmeadows]

Based on the definition for Quantifier, a valid Quantifier would include ??, making things like a?? a valid regular expression body, even though it's redundant. Is that an oversight?

I'll note that a??? is not a valid production, though, so it's only limited to 1 or 2 ?s.

[claudepache]

At first sight, /a??/ is just the non-greedy version of/a?/, i.e., the latter is equivalent to /a|/ and the former to /|a/.

[claudepache]

At first sight, /a??/ is just the non-greedy version of/a?/, i.e., the latter is equivalent to /a|/ and the former to /|a/.

[claudepache]

That is to say, the two ?s have two completely different meanings: the first one modifies an Atom and means “optional”, and the second one modifies a Quantifier and means “non-greedy”.

[claudepache]

That is to say, the two ?s have two completely different meanings: the first one modifies an Atom and means “optional”, and the second one modifies a Quantifier and means “non-greedy”.

[littledan]

Thanks for the answer, looks like the case is closed.

[littledan]

Thanks for the answer, looks like the case is closed.