mirror of
https://github.com/luau-lang/rfcs.git
synced 2025-04-17 18:33:53 +01:00
59 lines
1.4 KiB
Markdown
59 lines
1.4 KiB
Markdown
# Named Function Expressions
|
|
|
|
## Summary
|
|
|
|
This proposes that the current function expressions, which are always anonymous (unnamed) be allowed to have names.
|
|
|
|
## Motivation
|
|
|
|
This would make some code more readable, enable luau to give function expressions names other than `<anonymous>` in stack traces and with `debug.info`, enable function expressions to be recursive (call themselves), and help in miscellaneous profiling and debugging tools.
|
|
|
|
## Design
|
|
|
|
The current grammar for function expressions is the following, taken from the `simpleexp` rule.
|
|
|
|
```
|
|
attributes 'function' funcbody
|
|
```
|
|
|
|
This proposal would change that grammar to the following.
|
|
|
|
```
|
|
attributes 'function' [NAME] funcbody
|
|
```
|
|
|
|
This adds an optional name in function expressions, which can be used like so:
|
|
|
|
```luau
|
|
foo(function factorial(n)
|
|
return if n == 1 then 1 else n * factorial(n - 1)
|
|
end)
|
|
```
|
|
|
|
It is also important to note where this creates a binding to the function expression, the following example should explain:
|
|
|
|
```luau
|
|
-- 'bar' is not bound here
|
|
|
|
local foo = function bar(n)
|
|
-- 'bar' is bound here
|
|
end
|
|
|
|
-- 'bar' is not bound here
|
|
```
|
|
|
|
## Drawbacks
|
|
|
|
This proposal would make table function field syntax impossible without a special case. An example of this syntax:
|
|
|
|
```luau
|
|
local t = {
|
|
function foo() end,
|
|
}
|
|
|
|
t.foo()
|
|
```
|
|
|
|
## Alternatives
|
|
|
|
The alternative is defining a function with `local function` declaration syntax, which allows for recursion and gives debugging names.
|