Matching a fixed number of repetitions in LPeG
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- Subject: Matching a fixed number of repetitions in LPeG
- From: Hinrik Örn Sigurðsson <hinrik.sig@...>
- Date: 2012年6月19日 19:04:51 +0000
I need to match a fixed number of repetitions of a pattern, so I tried
the multiply_pattern() function listed in
http://lua-users.org/wiki/LpegRecipes. However, for me it never
matches. I also tried the function listed in the referenced blog post,
with the same result. Has LPeG changed significantly since this was
written, or am I using it wrong? Here is the code I'm using:
function multiply_pattern(item, count)
return lpeg.Cmt(lpeg.P(true), function(s, i)
local set, offset = {}, i
for j = 1, count do
set[j], offset = lpeg.match(item * lpeg.Cp(), s, offset)
if not offset then
return false
end
end
return offset, set
end)
end
print(lpeg.match(lpeg.C(multiply_pattern('a', 2)), 'aa')) --> nil