31 lines
1.4 KiB
Lua
31 lines
1.4 KiB
Lua
Class = {
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classname = "Class aka Object aka Root-Of-Tree",
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new = function(s,t)
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s.__index = s
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local instance = setmetatable(t or {}, s)
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instance.parent = s
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return instance
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end
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}
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Animal = Class:new{classname="Animal", speak=function(s) return s.voice or "("..s.classname.." has no voice)" end }
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Cat = Animal:new{classname="Cat", voice="meow"}
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Dog = Animal:new{classname="Dog", voice="woof"}
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Lab = Dog:new{classname="Lab", voice="bark"}
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Collie = Dog:new{classname="Collie"} -- subclass without a unique voice
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print("Animal:speak(): " .. Animal:speak())
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print("Cat:speak(): " .. Cat:speak())
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print("Dog:speak(): " .. Dog:speak())
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print("Lab:speak(): " .. Lab:speak())
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print("Collie:speak(): " .. Collie:speak())
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max = Collie:new{voice="Hi, I am Max the talking Collie!"} -- instance with a unique voice
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print("max:speak(): " .. max:speak())
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print("max himself is (instance): " .. max.classname)
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print("max's parent is (class): " .. max.parent.classname)
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print("max's parent's parent is (class): " .. max.parent.parent.classname)
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print("max's parent's parent's parent is (class): " .. max.parent.parent.parent.classname)
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print("max's parent's parent's parent's parent is (class): " .. max.parent.parent.parent.parent.classname)
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print("max's parent's parent's parent's parent's parent is (nil reference): " .. tostring(max.parent.parent.parent.parent.parent))
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