Go style channels in Lua
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- Subject: Go style channels in Lua
- From: Marek Majkowski <marek@...>
- Date: 2013年8月30日 15:30:02 +0100
Hi,
Lua supports cooperative coroutines out of the box, which is great.
Unfortunately Lua lacks built-in communication primitives. To fill the
void I've implemented Go style channels in pure Lua.
Of course abstract channels without any concurrent IO aren't terribly
useful, but fortunately the code is pretty straightforward and
adapting it to your event loop shouldn't be a problem.
The code is here (~400 lines of code + ~200 of tests):
https://github.com/majek/lua-channels/blob/master/task.lua
For example, here's Eratosthenes sieve following Russ Cox explanation:
http://swtch.com/~rsc/thread/
Code: https://github.com/majek/lua-channels/blob/master/sieve.lua
local task = require('task')
local function counter(c)
local i = 2
while true do
c:send(i)
i = i + 1
end
end
local function filter(p, recv_ch, send_ch)
while true do
local i = recv_ch:recv()
if i % p ~= 0 then
send_ch:send(i)
end
end
end
local function sieve(primes_ch)
local c = task.Channel:new()
task.spawn(counter, c)
while true do
local p, newc = c:recv(), task.Channel:new()
primes_ch:send(p)
task.spawn(filter, p, c, newc)
c = newc
end
end
local function main()
local primes = task.Channel:new()
task.spawn(sieve, primes)
for i = 1, 10 do
print(primes:recv())
end
end
task.spawn(main)
task.scheduler()