uces as many values as matched by the loop.
A capture produces a value only when it succeeds.
For instance,
the pattern <code>lpeg.C(lpeg.P"a"^-1)</code>
produces the empty string when there is no <code>"a"</code>
(because the pattern <code>"a"?</code> succeeds),
while the pattern <code>lpeg.C("a")^-1</code>
does not produce any value when there is no <code>"a"</code>
(because the pattern <code>"a"</code> fails).
</p>

<p>
Usually,
LPeg evaluates all captures only after (and if) the entire match succeeds.
D