How to forward declare function that referenced a struct?

[codehz]

example:

local F = @function(): S
local S = @record{ f: F }

got error: undeclared symbol 'S'

[edubart]

You can only do this using <forwarddecl> annotation, here is an example:

local S <forwarddecl> = @record{} -- declare S with incomplete fields
local F = @function(): S -- use S
S = @record{ f: F } -- define S fields

Another option is to use S inside its definition:

local S = @record{ f: function(): S }

[edubart]

The requirement of using pointers to incomplete types was relaxed for function references since commit 14acb91 , I've edited the answer accordingly.