Functions

Size & Scope

• Functions should remain small and do a singular task
• Functions shouldn't really exceed 10 lines, if it is, you are likely doing more than one thing
• Utility functions should be in their own file, and then the use of require to call them into the main script.

Example

functions.lua

    ---@class functions
    local functions = {} 

    ---@param message string
    function functions.log(message)
        tes3mp.LogMessage(enumerations.log.VERBOSE, message)
    end

    return functions

main.lua

    ---@class core
    local core = {}

    core.functions = require 'custom.example.functions'

    function core.onServerPostInit()
        core.functions.log("Hello World!")
    end

    customEventHooks.registerHandler("onServerPostInit", core.onServerPostInit)

    return core

Naming

• Local functions should only be in camelCase, while global functions should be in PascalCase
• Function names should start with a leading verb.

Example

BAD

    function player() -- global
    local function PlayerDrop() -- local

GOOD

    function GetPlayerObject() -- global
    local function dropPlayer() -- local

Parameters

Parameter Count

Never exceed 3 parameters, doing so means that you should probably create a table and then pass the table as an argument.

Example

BAD

    function CreateChar(name, age, height, birthday, nationality)
    end

GOOD

    function CreateChar(char)
    end

Avoid passing implied functions as arguments

Just declare the function as a local variable and then pass the variable as the argument This benefits performance (especially when coroutines/threads are used). Beyond that, it will also increase said readability of the code.

BAD

    customEventHooks.registerHandler("onServerInit", function()
        print("Hello")
    end)

GOOD

    local core = {}
    core.onServerInit = function()
        print("Hello")
    end
    customEventHooks.registerHandler("onServerInit", core.onServerInit)

Documentation

Always use lua-language-server annotation, this not only helps you remember the structure and how your code works, it provides an API so that you can see it when you call functions in other files.

    --- Puts a space between a first and last name
    ---@param first string first name
    ---@param last string last name
    ---@return string full name
    function core.formatName(first, last)
        return first .. ' ' .. last
    end

Nesting

Never nest if possible. Do not exceed 4 levels of indentation. Use guard clauses where applicable. Nesting code makes the code dificult to read, it also makes it seem as if it is doing multiple things.

BAD

    function core.getFullName(first, last)
        if first and last then
            return first .. last
        else
            return nil
        end
    end

GOOD

    function core.getFullName(first, last)
        if not (first and last) then return end
        return first .. last
    end