Manuel Simon Hirsig
121 lines
3.8 KiB
Lua
121 lines
3.8 KiB
Lua
if getmetatable(getfenv(0)) == false then return end
|
|
local setmetatable, setfenv, getglobal, _G = setmetatable, setfenv, getglobal, getfenv(0)
|
|
|
|
local PRIVATE, FIELD, PUBLIC, ACCESSOR, MUTATOR = 0, 0, 1, 2, 4
|
|
local PUBLIC_FIELD, PUBLIC_ACCESSOR, PUBLIC_MUTATOR = PUBLIC+FIELD, PUBLIC+ACCESSOR, PUBLIC+MUTATOR
|
|
local READ, WRITE = 0, 1
|
|
local OPERATION = { [FIELD]=READ, [ACCESSOR]=READ, [MUTATOR]=WRITE }
|
|
|
|
local function error(msg, ...) return _G.error(format(msg or '', unpack(arg)) .. '\n' .. debugstack(), 0) end
|
|
local function import_error() error('Import error.') end
|
|
local function definition_error() error('Invalid definition.') end
|
|
local function collision_error(key) error('"%s" already exists.', key) end
|
|
|
|
local nop, id = function() end, function(v) return v end
|
|
|
|
local interface_eq = function() return true end
|
|
local INTERFACE = setmetatable({}, { __eq=interface_eq })
|
|
|
|
local function proxy_mt(values, mutators, eq)
|
|
return {
|
|
__metatable = false,
|
|
__index = values,
|
|
__newindex = function(_, k, v) return mutators[k](v) end,
|
|
__eq = eq,
|
|
}
|
|
end
|
|
|
|
local definition_helper_mt = { __metatable=false }
|
|
function definition_helper_mt:__index(k)
|
|
tinsert(self.definition_modifiers, k)
|
|
return self
|
|
end
|
|
do
|
|
local TYPE = { get=ACCESSOR, set=MUTATOR }
|
|
function definition_helper_mt:__newindex(k, v) self=__[self]
|
|
if type(k) ~= 'string' or not strfind(k, '^[_%a][_%w]*') then definition_error() end
|
|
if v ~= self.interface then
|
|
self.defined[OPERATION[type]..k] = self.defined[OPERATION[type]..k] and collision_error(k) or true
|
|
self[type], self[self.definition_access+type] = v, v
|
|
elseif _G[k] ~= nil or error(nil) then
|
|
_G[k] = v
|
|
end
|
|
self.definition_access, self.definition_modifiers = nil, nil
|
|
end
|
|
end
|
|
|
|
local import
|
|
do
|
|
local TYPES = {FIELD, ACCESSOR, MUTATOR}
|
|
function import(self, interface)
|
|
local module = (interface == INTERFACE or import_error()) and __[interface]
|
|
for _, type in TYPES do
|
|
for k, v in module[PUBLIC+type] do
|
|
if not self.defined[OPERATION[type]..k] then
|
|
self.defined[OPERATION[type]..k], self[type][k] = true, v
|
|
end
|
|
end
|
|
end
|
|
end
|
|
end
|
|
|
|
local global_default_mt, nop_default_mt = { __index=getglobal }, { __index=nop }
|
|
|
|
local global_mt = { __metatable=false }
|
|
function global_mt:__index(key)
|
|
if key ~= 'module' then return end
|
|
local definition_helper = setmetatable({}, definition_helper_mt)
|
|
local environment, interface = {}, {}
|
|
local accessors = setmetatable(
|
|
{
|
|
private = function() self.definition_access = PRIVATE; return definition_helper end,
|
|
public = function() self.definition_access = PUBLIC; return definition_helper end,
|
|
},
|
|
global_default_mt
|
|
)
|
|
local public_accessors = {}
|
|
local mutators = setmetatable({}, nop_default_mt)
|
|
local public_mutators = setmetatable({}, nop_default_mt)
|
|
local fields = setmetatable(
|
|
{
|
|
_G = _G,
|
|
_I = interface,
|
|
_E = environment,
|
|
import = function(interface) import(self, interface) end,
|
|
error = error,
|
|
nop = nop,
|
|
id = id,
|
|
},
|
|
{ __index=function(_, key) return accessors[key]() end }
|
|
)
|
|
local public_fields = setmetatable(
|
|
{},
|
|
{ __index=function(_, key) return public_accessors[key]() end }
|
|
)
|
|
setmetatable(environment, proxy_mt(fields, mutators))
|
|
setmetatable(interface, proxy_mt(public_fields, public_mutators, interface_eq))
|
|
self = {
|
|
defined = {
|
|
[FIELD..'_G'] = true,
|
|
[FIELD..'_I'] = true,
|
|
[FIELD..'_E'] = true,
|
|
[FIELD..'import'] = true,
|
|
[FIELD..'_'] = true,
|
|
[FIELD..'error'] =true,
|
|
[FIELD..'nop'] = true,
|
|
[FIELD..'id'] = true,
|
|
[ACCESSOR..'public'] = true,
|
|
[ACCESSOR..'private'] = true,
|
|
},
|
|
[FIELD] = fields,
|
|
[PUBLIC_FIELD] = public_fields,
|
|
[ACCESSOR] = accessors,
|
|
[PUBLIC_ACCESSOR] = public_accessors,
|
|
[MUTATOR] = mutators,
|
|
[PUBLIC_MUTATOR] = public_mutators,
|
|
interface = interface,
|
|
}
|
|
setfenv(2, environment)
|
|
return interface
|
|
end
|
|
setmetatable(_G, global_mt) |