Userdata: Difference between revisions
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>Camoy I wonder why the TOC didn't come up... |
>Blocco Most people looking at the wiki like contractions, especially in this case. |
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==Userdata== | ==Userdata== | ||
===What is a Userdata?=== | ===What is a Userdata?=== | ||
A userdata is the type Lua uses for data structures in the underlying C program. There | A userdata is the type Lua uses for data structures in the underlying C program. There aren't native Lua functions for handling those types, they must be handled via [[Metatables]]. All Roblox objects and events are userdata Lua type. | ||
===Using Userdatas=== | ===Using Userdatas=== | ||
Revision as of 22:39, 24 December 2010
Userdata
What is a Userdata?
A userdata is the type Lua uses for data structures in the underlying C program. There aren't native Lua functions for handling those types, they must be handled via Metatables. All Roblox objects and events are userdata Lua type.
Using Userdatas
You can create a new userdata by passing true to the undocumented newproxy function. This userdata cannot be used for anything other than invoking functions via its metatable.
Example
local ud = newproxy(true) -- new userdata with an empty metatable
getmetatable(ud).__index = {Foo = "Bar"} -- index metamethod
print(type(ud), ud.Foo)
Output:
userdata: 0x631fc8 Bar
