luau-lang/rfcs
1
0
Fork 0
mirror of https://github.com/luau-lang/rfcs.git synced 2025-05-04 10:43:48 +01:00
Code Issues Projects Releases Packages Wiki Activity

Specify behavior for getmetatable

Browse source
This commit is contained in:
ffrostfall 2025-02-04 00:52:01 -05:00 • committed by GitHub
parent 97d436849f
commit 585ce6ba37
Signed by: DevComp
GPG key ID: B5690EEEBB952194
1 changed files with 6 additions and 0 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

6
docs/metatable-type-functions.md
View file

@ -41,6 +41,9 @@ type Identity = setmetatable<{
}> }>
``` ```
When a non-table type (number, boolean) is passed into the type function, it should result in an error. This includes classes.
If the type is an intersection/union of tables, then the metatable should be applied to every
### `getmetatable` Type Function ### `getmetatable` Type Function
In the following code example, `ReversedIdentity` should evaluate to `{ __index: typeof(animal) }`: In the following code example, `ReversedIdentity` should evaluate to `{ __index: typeof(animal) }`:
@ -66,6 +69,9 @@ type metatable = {
type MetatableType = getmetatable<setmetatable<{}, metatable>> type MetatableType = getmetatable<setmetatable<{}, metatable>>
``` ```
If the type passed into the type function doesn't have a metatable and it *could* have a metatable (so primitives, singletons, classes, and tables), then it will return nil.
If the type passed in is an intersection/union, then it will return an interesction/union respectively.
## Drawbacks ## Drawbacks
Introducing a large library of "global" type functions can clutter naming space for users. Introducing a large library of "global" type functions can clutter naming space for users.