reactor.lua v0.3

--[[
kazagistar's event reactor
Do whatever you want with it, no rights reserved, as per WTFPL
(http://sam.zoy.org/wtfpl/COPYING)

The point of this program is to provide a centralized observer pattern. Events
can be generated by hardware and software, and any "observer" function which
is registered will be called.

reactor:register(event, name, func): Registers a function as an event listener,
given the event string and a unique name string to ID this function. For the
parameters passed to the function, see the documentation of the event sender,
but they are always passed the event and name. If you want to listen for any
event, listen for "reactor.any", but dont overuse this, as it can lead to poor
performance.

reactor:unregister(event, name): Unregisters a function from an event, given
the event and name.

reactor:event(event, ...): Pushes an event to resolve.

reactor:run() Starts the reactor running. Set reactor.running = false to stop
--]]
if not reactor then

reactor = {}
reactor.observer = {}
reactor.register = function(r, event, name, func)
    if not event then
        event = "reactor.any"
    end
    if not r.observer[event] then
        r.observer[event] = {}
    end
    r.observer[event][name]=func
end
reactor.unregister = function(r, event, name)
    if event == nil then
        event = "reactor.any"
    end
    r:event("reactor.delete", event, name)
end
reactor.event = function(r, ...)
    os.queueEvent(...)
end
reactor.resolve = function(r, event, ...)
    local args = {...}
    if event == "reactor.delete" then
        local event, name = unpack(args)
        r.observer[event][name] = nil
        if not next(r.observer[event]) then
            r.observer[event] = nil
        end
    end
    if r.observer[event] then
        for name, func in pairs(r.observer[event]) do
            func(event, name, unpack(args))
        end
    end
    if r.observer["reactor.any"] then
        for name, func in pairs(r.observer["reactor.any"]) do
            func(event, name, unpack(args))
        end
    end
end


-- This utility function is stupidly useful, so I put it here
reactor.capture = function(str, ...) return str, arg end

-- Until the reactor.running = false, it will pull events and share em around
reactor.run = function(r)
    r.running = true
    while r.running do
        r:resolve(coroutine.yield())
    end
end

end