Method Dispatch

Pick behavior from an action name the way a method dispatcher would.
method dispatch Object methods often select behavior from an action name and the object's current fields.
                            action
                            action = "open" (default)action = "close"action = "pause"
                        

                            method_dispatch.lua
                        
Replay: real traced execution (multi-file project)

                            local action = "open"
local label = "unknown"
if action == "open" then
    label = "opening"
end
if action == "close" then
    label = "closing"
end
if action == "pause" then
    label = "paused"
end
local message = ({action = action, label = label}).action .. ":" .. ({action = action, label = label}).label
print("action=" .. action)
print("message=" .. message)
local action = "close"
local label = "unknown"
if action == "open" then
    label = "opening"
end
if action == "close" then
    label = "closing"
end
if action == "pause" then
    label = "paused"
end
local message = ({action = action, label = label}).action .. ":" .. ({action = action, label = label}).label
print("action=" .. action)
print("message=" .. message)
local action = "pause"
local label = "unknown"
if action == "open" then
    label = "opening"
end
if action == "close" then
    label = "closing"
end
if action == "pause" then
    label = "paused"
end
local message = ({action = action, label = label}).action .. ":" .. ({action = action, label = label}).label
print("action=" .. action)
print("message=" .. message)

                        
1action ← open, label ← unknown1local action→ open = "open" --@action="close", "pause"2local label→ unknown = "unknown"3if action == "open" then⋯
2label ← opening⋯2local label = "unknown"3if actionopen == "open" then4    label→ opening = "opening"5end⋯
3message ← open:opening⋯11end12local message→ open:opening = ({action = action, label = label}).actionopen .. ":" .. ({action = action, label = label}).labelopening13print("action=" .. actionopen)14print("message=" .. messageopen:opening)⋯outputaction=open
message=open:opening
1action ← close, label ← unknown1local action→ close = "close"2local label→ unknown = "unknown"3if action == "open" then⋯
2label ← closing⋯5end6if actionclose == "close" then7    label→ closing = "closing"8end⋯
3message ← close:closing⋯11end12local message→ close:closing = ({action = action, label = label}).actionclose .. ":" .. ({action = action, label = label}).labelclosing13print("action=" .. actionclose)14print("message=" .. messageclose:closing)⋯outputaction=close
message=close:closing
1action ← pause, label ← unknown1local action→ pause = "pause"2local label→ unknown = "unknown"3if action == "open" then⋯
2label ← paused⋯8end9if actionpause == "pause" then10    label→ paused = "paused"11end⋯
3message ← pause:paused⋯11end12local message→ pause:paused = ({action = action, label = label}).actionpause .. ":" .. ({action = action, label = label}).labelpaused13print("action=" .. actionpause)14print("message=" .. messagepause:paused)⋯outputaction=pause
message=pause:paused