[lua]协同式多任务，统筹运用

-- CPM:关键路径法(Critical Path Method)
jobBase = {
    schedule = function ( self, job, task, ... ) --由具体job构造任务列表 
        local finale = false
        local msg = nil
        local rc = nil
        local params = table.pack(self, task, ...)
        repeat
            local task = params[2];
            local fn = job[task]
            if type(fn) == "function"
            then rc = fn(table.unpack(params, 3)) end
            finale = (task == "finale")
            msg = self.name.."["..task.."] done!"
            if not finale
            then
                -- yield 传回进度描述及任务反馈
                -- 打包调度入参
                params = table.pack(coroutine.yield(msg, rc))
            end
        until finale
        self.co = nil -- over
        return msg, rc
    end;
    perform = function ( self, task, ... )
        local co = self.co or coroutine.create(self.schedule)
        if self.co == nil
        then self.co = co end
        return coroutine.resume(co, self, task, ...)
    end;
}--jobBase
---------------------------------------------------------------
--记得华罗庚的统筹方法论对烧水泡茶的描述过程
--就是多任务协调的执行程序
--示例：project, another两项任务节点的调度与描述
--{}, 构造描述的脚本模式
local project = {
    name = "projectSample";
    perform = jobBase.perform;
    schedule = function ( self, task, ... )
        local todo = {
        ["stage1"] = function()
        end;
        ["stage2"] = function()
        end;
        ["stage3"] = function()
        end;
        ["finale"] = function()end;
        }
        return jobBase.schedule(self, todo, task, ...)
    end
}
--记得区分对象调用与域调用，一不小心就写成. 就无法识别self了
print(project:perform("stage1"))
--creator, object based; 基于创建对象，对象扩展的脚本模式
function jobBase.create( name )
    local o = {name = name}
    return setmetatable(o, {__index = jobBase})
end
local another = jobBase.create("anotherProject")
function another:schedule( task, ... )
    local todo = {
    ["stage1"] = function()
    end;
    ["stage2"] = function()
    end;
    ["finale"] = function()end;
    }
    return getmetatable(self).__index.schedule(self, todo, task, ...)
end
print(another:perform("stage1"))
print(project:perform("stage2"))
print(project:perform("stage3"))
print(another:perform("stage2"))
print(project:perform("finale"))
print(another:perform("finale"))