Manuel Simon Hirsig
89 lines
2.8 KiB
Lua
89 lines
2.8 KiB
Lua
local band, bor, bnot = bit.band, bit.bor, bit.bnot
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local _G = getfenv(0)
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local FIELD, ACCESSOR, MUTABLE, PUBLIC = 1, 2, 4, 8
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local ACCESSOR_KEY, MUTABLE_KEY, PUBLIC_KEY = 'accessor', 'mutable', 'public'
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local MODIFIER = {[ACCESSOR_KEY]=ACCESSOR, [MUTABLE_KEY]=MUTABLE, [PUBLIC_KEY]=PUBLIC}
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local _state, _data, _metadata = {}, {}, {}
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--local function_mt = {
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-- __call = function(self, ...)
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-- local f = state[self]
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-- getfenv(f).__ = {}
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-- f(unpack(arg))
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-- getfenv(f).__ = temp
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-- end,
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--}
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local metadata_mt = {__index=function() return 0 end}
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local environment_mt = {
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__metatable = false,
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__index = function(self, key)
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local value, properties = _data[self][key], _metadata[self][key]
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if band(FIELD, properties) ~= 0 then
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return value
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elseif band(ACCESSOR, properties) ~= 0 then
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return value(key)
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else
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return _G[key] or error('No key "'..key..'".', 2)
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end
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end,
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__newindex = function(self, key, value)
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local properties = _metadata[self][key]
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if properties == 0 then
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_metadata[self][key] = FIELD
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elseif band(MUTABLE, properties) == 0 then
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error('"'..key..'" is immutable.', 2)
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end
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_data[self][key] = value
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end,
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}
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local interface_mt = {
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__metatable = false,
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__index = function(self, key)
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local value, properties = _data[self][key], _metadata[self][key]
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if band(FIELD, properties) ~= 0 then
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return value
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elseif band(ACCESSOR, properties) ~= 0 then
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return value(key)
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else
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error('No key "'..key..'".', 2)
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end
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end,
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__newindex = function() error('Unsupported operation.', 2) end,
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}
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local modifier_mt = {
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__metatable = false,
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__call = function(self, key)
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_state[self] = bor(_state[self], MODIFIER[key])
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return self
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end,
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__index = function(self, key)
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local value = MODIFIER[key]
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if not value then error('Unsupported operation.', 2) end
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_state[self] = bor(_state[self], value)
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return self
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end,
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__newindex = function(self, key, value)
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if _metadata[self][key] ~= 0 then error('Duplicate key "'..key..'".', 2) end
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_data[self][key] = value
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_metadata[self][key] = _state[self]
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_state[self] = 0
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end,
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}
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function aux_module()
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local modifier, environment, interface = setmetatable({}, modifier_mt), setmetatable({}, environment_mt), setmetatable({}, interface_mt)
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local data = {[ACCESSOR_KEY]=modifier, [MUTABLE_KEY]=modifier, [PUBLIC_KEY]=modifier}
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local metadata = setmetatable({[ACCESSOR_KEY]=ACCESSOR, [MUTABLE_KEY]=ACCESSOR, [PUBLIC_KEY]=ACCESSOR}, metadata_mt)
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_data[modifier], _data[environment], _data[interface] = data, data, data
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_metadata[modifier], _metadata[environment], _metadata[interface] = metadata, metadata, metadata
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_state[modifier] = 0
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environment.mutable.__ = nil
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environment.m = environment -- TODO for compatibility, remove later
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environment.private = environment -- TODO for compatibility, remove later
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setfenv(2, environment)
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return interface
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end |