mirror of https://github.com/kepler155c/opus
50 lines
1.1 KiB
Lua
50 lines
1.1 KiB
Lua
-- From http://lua-users.org/wiki/SimpleLuaClasses
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-- (with some modifications)
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-- class.lua
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-- Compatible with Lua 5.1 (not 5.0).
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return function(base)
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local c = { } -- a new class instance
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if type(base) == 'table' then
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-- our new class is a shallow copy of the base class!
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if base._preload then
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base = base._preload(base)
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end
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for i,v in pairs(base) do
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c[i] = v
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end
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c._base = base
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end
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-- the class will be the metatable for all its objects,
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-- and they will look up their methods in it.
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c.__index = c
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-- expose a constructor which can be called by <classname>(<args>)
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setmetatable(c, {
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__call = function(class_tbl, ...)
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local obj = { }
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setmetatable(obj,c)
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if class_tbl.init then
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class_tbl.init(obj, ...)
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else
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-- make sure that any stuff from the base class is initialized!
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if base and base.init then
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base.init(obj, ...)
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end
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end
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return obj
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end
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})
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c.is_a =
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function(self, klass)
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local m = getmetatable(self)
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while m do
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if m == klass then return true end
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m = m._base
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end
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return false
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end
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return c
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end
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