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author | Alexey Zaytsev <alexey.zaytsev@gmail.com> | 2008-07-18 00:47:28 +0400 |
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committer | Alexey Zaytsev <zaytsev.a@protei.ru> | 2008-07-18 00:47:28 +0400 |
commit | 5589a6e296427110474e74fbbd3ef9c512fe0ff4 (patch) | |
tree | 388c521c3b6262ccda9385fa29f36df7a4851e6d /com32/lua/test/sieve.lua | |
parent | fa6a60e177786fea2b834691a66319fd3b177038 (diff) | |
download | syslinux-5589a6e296427110474e74fbbd3ef9c512fe0ff4.tar.gz |
Import Lua 5.1.3
Signed-off-by: Alexey Zaytsev <zaytsev.a@protei.ru>
Diffstat (limited to 'com32/lua/test/sieve.lua')
-rw-r--r-- | com32/lua/test/sieve.lua | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/com32/lua/test/sieve.lua b/com32/lua/test/sieve.lua new file mode 100644 index 00000000..0871bb21 --- /dev/null +++ b/com32/lua/test/sieve.lua @@ -0,0 +1,29 @@ +-- the sieve of of Eratosthenes programmed with coroutines +-- typical usage: lua -e N=1000 sieve.lua | column + +-- generate all the numbers from 2 to n +function gen (n) + return coroutine.wrap(function () + for i=2,n do coroutine.yield(i) end + end) +end + +-- filter the numbers generated by `g', removing multiples of `p' +function filter (p, g) + return coroutine.wrap(function () + while 1 do + local n = g() + if n == nil then return end + if math.mod(n, p) ~= 0 then coroutine.yield(n) end + end + end) +end + +N=N or 1000 -- from command line +x = gen(N) -- generate primes up to N +while 1 do + local n = x() -- pick a number until done + if n == nil then break end + print(n) -- must be a prime number + x = filter(n, x) -- now remove its multiples +end |