Usage

After installing and enabling Umbrella, you should immediately see your project populated by type analysis.

However in more complex code, the coverage is limited. The language server has no idea what types your own functions accept or what they return, so nothing interacting with your own code benefits from type analaysis. To make the most of the type stubs you will need to annotate your own code.

Annotating variables

You can declare the type of a variable by preceding its declaration with ---@type TypeName. This can be useful to catch bugs: ordinarily the language server will accept any assignment to a variable, but if you’ve told it what type the variable is, it will warn you when you assign the wrong type to it.

---@type IsoZombie
local zombie = getCell():getZombieList():get(0)

-- warning: cannot assign IsoPlayer to IsoZombie
zombie = getPlayer()

Annotating functions

Because the language server doesn’t know what types your functions expect or return, it can’t perform any any autocompletion or type checking for function parameters or return values. You can use type annotations to tell it what types your function to enable these features in your own code. Use @param name TypeName to declare the type of a parameter, and @return TypeName to declare the return type of the function.

---@param zombie IsoZombie
---@param amount number
---@return number
local function doSomething(zombie, amount)
    -- ...
end

-- warning: cannot assign IsoPlayer to IsoZombie
doSomething(getPlayer(), 5)

Advanced annotations

There is far more you can do with type annotations, such as declaring your own classes. Umbrella itself is just a bunch of type annotations; you can do anything it does in your own code.

What has been presented on this page is enough for basic usage, but advanced users may want to reference the LuaLS wiki for full information about type annotations.

Note

EmmyLua users can ignore warnings about generics being WIP: while they are very incomplete in LuaLS, they work near perfectly in EmmyLua.