43 lines
899 B
Lua
43 lines
899 B
Lua
--[[
|
|
A 'Symbol' is an opaque marker type that can be used to signify unique
|
|
statuses. Symbols have the type 'userdata', but when printed to the console,
|
|
the name of the symbol is shown.
|
|
]]
|
|
|
|
local Symbol = {}
|
|
|
|
--[[
|
|
Creates a Symbol with the given name.
|
|
|
|
When printed or coerced to a string, the symbol will turn into the string
|
|
given as its name.
|
|
]]
|
|
function Symbol.named(name)
|
|
assert(type(name) == "string", "Symbols must be created using a string name!")
|
|
|
|
local self = newproxy(true)
|
|
|
|
local wrappedName = ("Symbol(%s)"):format(name)
|
|
|
|
getmetatable(self).__tostring = function()
|
|
return wrappedName
|
|
end
|
|
|
|
return self
|
|
end
|
|
|
|
--[[
|
|
Create an unnamed Symbol. Usually, you should create a named Symbol using
|
|
Symbol.named(name)
|
|
]]
|
|
function Symbol.unnamed()
|
|
local self = newproxy(true)
|
|
|
|
getmetatable(self).__tostring = function()
|
|
return "Unnamed Symbol"
|
|
end
|
|
|
|
return self
|
|
end
|
|
|
|
return Symbol |