parallel.lua

local os = require "craftos.os"

local parallel = {}

local function run(fn, min)
    local coros = {}
    for i, v in ipairs(fn) do
        if type(v) ~= "function" then error("bad argument #" .. i .. " (expected function, got " .. type(v) .. ")", 2) end
        coros[i] = {coro = coroutine.create(v), filter = nil, pos = i}
    end
    local ev = {n = 0}
    while #coros >= min do
        local i = 1
        while i < #coros do
            if coros[i].filter == nil or coros[i].filter == ev[1] then
                local args = ev
                repeat
                    local res = table.pack(coros[i].coro(table.unpack(args, 1, args.n)))
                    if not res[1] then error(res[2], 0) end
                    if res[2] == "syscall" then args = table.pack(coroutine.yield(table.unpack(res, 1, res.n)))
                    else coros[i].filter = res[2] end
                until res[2] ~= "syscall"
                if coros[i]:status() == "dead" then
                    local n = coros[i].pos
                    table.remove(coros, i)
                    if #coros < min then return n end
                    i=i-1
                end
            end
            i=i+1
        end
        ev = table.pack(os.pullEvent())
    end
    return 1 -- this should never be hit
end

function parallel.waitForAny(...)
    return run({...}, select("#", ...))
end

function parallel.waitForAll(...)
    return run({...}, 1)
end

return parallel