Manuel Simon Hirsig
86 lines
3.8 KiB
Lua
86 lines
3.8 KiB
Lua
if getmetatable(getfenv(0)) == false then return end
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local tinsert, tremove, getn, setn, strfind, type, setmetatable, setfenv, _G = tinsert, tremove, getn, table.setn, strfind, type, setmetatable, setfenv, getfenv(0)
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local PRIVATE, PUBLIC, FIELD, ACCESSOR, MUTATOR = 0, 1, 2, 4, 6
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local MODES = { FIELD, ACCESSOR, MUTATOR }
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local READ, WRITE = '', '='
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local OPERATION = { [FIELD]=READ, [ACCESSOR]=READ, [MUTATOR]=WRITE }
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local META = { get=ACCESSOR, set=MUTATOR }
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local function error(msg, ...) return _G.error(format(msg or '', unpack(arg)) .. '\n' .. debugstack(), 0) end
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local nop, id = function() end, function(v) return v end
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local interface_lt = function() return true end
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local INTERFACE = setmetatable({}, { __lt=interface_lt })
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local function proxy_mt(fields, mutators, lt)
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return { __metatable=false, __index=fields, __newindex=function(_, k, v) return mutators[k](v) end, __lt=lt }
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end
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local _module, _access, _name = {}, {}, {}
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local definition_helper_mt = { __metatable=false }
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function definition_helper_mt:__index(k)
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_name[self] = _name[self] and error('Invalid modifier "%s".', k) or k
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return self
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end
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function definition_helper_mt:__newindex(k, v)
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local module, name, mode
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module, name = _module[self], _name[self]
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if name then mode = META[k] or error('Invalid modifier "%s"', k) else name, mode = k, FIELD end
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if type(name) ~= 'string' or not strfind(name, '^[_%a][_%w]*') then error('Invalid identifier "%s".', name) end
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module.defined[name .. OPERATION[mode]] = module.defined[name .. OPERATION[mode]] and error('Duplicate identifier "%s".', name) or true
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module[mode][name], module[_access[self]+mode][name] = v, v
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_access[self], _name[self] = nil, nil
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end
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local function include(self, interface)
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local module = (interface < INTERFACE or error'Import error.') and _module[interface]
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for _, mode in MODES do
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for k, v in module[PUBLIC+mode] do
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if not self.defined[k .. OPERATION[mode]] then
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self.defined[k .. OPERATION[mode]], self[mode][k] = true, v
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end
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end
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end
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end
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local nop_default_mt = { __index=function() return nop end }
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local env = setmetatable({}, {
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__metatable = false,
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__newindex = function(_, k)
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if _G[k] then _G.error(nil) end
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local module, environment, interface, definition_helper, modifiers, accessors, mutators, fields, public_accessors, public_mutators, public_fields
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environment, interface, definition_helper = {}, {}, setmetatable({}, definition_helper_mt)
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accessors = { private=function() _access[definition_helper] = PRIVATE; return definition_helper end, public=function() _access[definition_helper] = PUBLIC; return definition_helper end }
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mutators = setmetatable({ _=nop }, { __index=function(_, k) return function(v) _G[k] = v end end })
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fields = setmetatable(
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{ _M=environment, _G=_G, include=function(interface) include(module, interface) end, error=error, nop=nop, id=id },
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{ __index=function(_, k) local accessor = accessors[k]; if accessor then return accessor() else return _G[k] end end }
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)
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public_accessors = setmetatable({}, nop_default_mt)
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public_mutators = setmetatable({}, nop_default_mt)
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public_fields = setmetatable({}, { __index=function(_, k) return public_accessors[k]() end })
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setmetatable(environment, proxy_mt(fields, mutators))
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setmetatable(interface, proxy_mt(public_fields, public_mutators, interface_lt))
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module = {
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defined = { _M=true, _G=true, include=true, error=true, nop=true, id=true, public=true, private=true, ['_=']=true },
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[ACCESSOR] = accessors,
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[MUTATOR] = mutators,
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[FIELD] = fields,
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[PUBLIC+ACCESSOR] = public_accessors,
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[PUBLIC+MUTATOR] = public_mutators,
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[PUBLIC+FIELD] = public_fields,
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}
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_module[definition_helper], _module[interface] = module, module
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_G[k] = interface
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setfenv(2, environment)
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end,
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})
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setmetatable(_G, {
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__metatable = false,
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__index = function(_, k) if k == 'module' then setfenv(2, env) end end,
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}) |