global return and named module

[codehz]

In lua, we can return value from a lua file, but it is impossible in nelua for now (because require return void, and cannot return type so it cannot be used as module namespace).

Idea: make this valid

mymodule.nelua:

local module = @record{}

function module.method() end

-- make global return can return anything (comptime or not)
return module

main.nelua:

local mod = require 'mymodule'

mod.method()

Alternative syntax(syntax sugar)

mymodule.nelua:

module function method() end

[edubart]

This is on the roadmap, and definitely will be done, it will be just like as Lua (as you first example). I expect this to be one of the next new language features.

[codehz]

the first syntax has a problem, you can only attach function to @record, since global module.INFO: string syntax is only available in global variable...

[edubart]

global module.INFO: string there is fine even if module is local, the global in that context is a "global" variable on the record type, not a global in the sense of the global scope, this is because the grammar needs a keyword before a declaration so the compiler knows that a variable is being declared, this solves many issues otherwise the grammar would have ambiguities with assignment, that is, while in Lua you can declare a variable without a keyword, in Nelua you can't, you always need global or local preceding a declaration, and I've choose global instead of local to explicitly declare variables inside a record because for me made more sense than local.

So the module system would be like:

local module = @record{}

-- A module function.
function module.f() end

-- A module variable.
global module.INFO: string

Then using:

local mod = require 'module'

-- Call module function
mod.f()

-- Use module variable
print(mod.INFO)

[codehz]

Ah, this explanation is very clear, thanks

[codehz]

BTW, why function module.f doesn't need any prefix? there are some inconsistencies in the grammar here

[edubart]

Just updating, modules system has been implemented recently, you can now return types from modules, it works as the first idea.