1 files changed, 64 insertions, 0 deletions
diff --git a/script/task.lua b/script/task.lua
new file mode 100644
index 00000000..bb1a7922
--- /dev/null
+++ b/script/task.lua
@@ -0,0 +1,64 @@
+local mt = {}
+mt.__index = mt
+mt.type = 'task'
+
+function mt:remove()
+    if self._removed then
+        return
+    end
+    self._removed = true
+    coroutine.close(self.task)
+end
+
+function mt:isRemoved()
+    return self._removed
+end
+
+function mt:step()
+    if self._removed then
+        return
+    end
+    local suc, res = coroutine.resume(self.task)
+    if not suc then
+        self:remove()
+        log.error(debug.traceback(self.task, res))
+        return
+    end
+    if coroutine.status(self.task) == 'dead' then
+        self:remove()
+    end
+    return res
+end
+
+function mt:fastForward()
+    if self._removed then
+        return
+    end
+    while true do
+        local suc = coroutine.resume(self.task)
+        if not suc then
+            self:remove()
+            break
+        end
+        if coroutine.status(self.task) == 'dead' then
+            self:remove()
+            break
+        end
+    end
+end
+
+function mt:set(key, value)
+    self.data[key] = value
+end
+
+function mt:get(key)
+    return self.data[key]
+end
+
+return function (callback)
+    local self = setmetatable({
+        data = {},
+        task = coroutine.create(callback),
+    }, mt)
+    return self
+end