46 lines
895 B
Lua
46 lines
895 B
Lua
---Generic class, useful for inheritence.
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---@class (exact) Class
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---@field private __index? table
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local Class = {}
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---@param o Class?
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---@return Class
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function Class:new(o)
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o = o or {}
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setmetatable(o, self)
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self.__index = self
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return o
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end
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---Object is an instance of class
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---This will start with the lowest class and loop over all the superclasses.
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---@param class table
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---@return boolean
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function Class:is(class)
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local mt = getmetatable(self)
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while mt do
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if mt == class then
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return true
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end
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mt = getmetatable(mt)
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end
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return false
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end
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---Return object if it is an instance of class, otherwise nil
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---@generic T
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---@param class T
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---@return `T`|nil
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function Class:as(class)
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return self:is(class) and self or nil
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end
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-- avoid unused param warnings in abstract methods
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---@param ... any
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function Class:nop(...) --luacheck: ignore 212
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end
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return Class
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