126 lines
2.8 KiB
Lua
126 lines
2.8 KiB
Lua
local oop = {}
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local function super_call(self, method_name, ...)
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local class = getmetatable(self)
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if not class then
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error("super() called on non-instance")
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end
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local base = rawget(class, "__base")
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if not base then
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error("super() called but no base class")
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end
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local fn = base[method_name]
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if not fn then
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error("base class has no method '" .. tostring(method_name) .. "'")
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end
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return fn(self, ...)
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end
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local function_def_cache = setmetatable({}, { __mode = "k" })
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function oop.setattr(target, key, value)
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target[key] = value
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end
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function oop.new(class, ...)
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local actual_class = class
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if type(class) == "function" then
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actual_class = function_def_cache[class]
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if not actual_class then
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actual_class = oop.class(class)
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function_def_cache[class] = actual_class
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end
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end
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local obj = setmetatable({}, actual_class)
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if actual_class.__init then
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actual_class.__init(obj, ...)
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end
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return obj
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end
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local function lookup_in_class(cls, key)
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local cur = cls
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while cur do
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local val = rawget(cur, key)
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if val ~= nil then
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return val
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end
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cur = rawget(cur, "__base")
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end
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return nil
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end
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function oop.class(def, base)
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local cls = {}
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cls.__name = "Anonymous"
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cls.__base = base
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cls.__index = function(self, key)
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local val = lookup_in_class(cls, key)
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if type(val) == "function" then
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return function(...)
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return val(self, ...)
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end
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end
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return val
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end
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function cls:super(method_name, ...)
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return super_call(self, method_name, ...)
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end
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function cls.setattr(target, key, value)
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return oop.setattr(target, key, value)
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end
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setmetatable(cls, {
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__index = base,
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__call = function(c, ...)
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return oop.new(c, ...)
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end
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})
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if type(def) == "string" then
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cls.__name = def
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elseif type(def) == "function" then
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def(cls)
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elseif def ~= nil then
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error("class definition must be a function or name string")
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end
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return cls
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end
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function oop.isinstance(obj, class)
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local mt = getmetatable(obj)
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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 = rawget(mt, "__base")
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end
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return false
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end
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function oop.issubclass(class, base)
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local mt = class
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while mt do
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if mt == base then
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return true
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end
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mt = rawget(mt, "__base")
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end
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return false
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end
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function oop.install(env)
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local target = env or _G
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target.class = oop.class
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target.new = oop.new
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target.setattr = oop.setattr
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target.isinstance = oop.isinstance
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target.issubclass = oop.issubclass
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end
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oop.install()
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return oop
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