Lua Cheat Sheet

Lua Cheat Sheet Pdf
Lua Tutorial

Local web = require('web') function printtable(t) for k,v in pairs(t) do print(k,v) end end results = web.query('Lua site:en.wikipedia.org') printtable(results). This is a general reference for scripting in Lua on Roblox. This cheat sheet is intended for beginner scripters. Access this cheat sheet here. Roblox Gamepad Input. This is a quick reference for implementing gamepad (controller) input on Roblox. This cheat sheet is. Local web = require('web') function printtable(t) for k,v in pairs(t) do print(k,v) end end results = web.query('Lua site:en.wikipedia.org') printtable(results).

This is a function 'cheat sheet' for Apollo extension by YellowAfterlife.
The extension can be acquired from GM:Marketplace or itch.io.
For questions/support, use forums (itch.io, GM forums), or send me an email.
A most up-to-date version of the manual is always available online.
The extension is currently available for Windows, Mac (GMS2 only), and Linux.

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lua_get_cwd()➜path

Lua states

lua_state_destroy(state_id)

lua_reset()

Adding Lua code

Managing global variables

lua_global_type(state_id, name)➜lua_type

Calling Lua code

lua_call_m(state_id, name, ...arguments)➜results_array

lua_call_wm(state_id, name, argument_array)➜results_array

Exposing GML scripts to Lua

lua_return_w(values:array)

lua_current

Automatically exposing scripts/functions

lua_bool(value)➜bool_value

lua_byref(array_or_struct, recursive = false)➜marker

Working with GM instance variables in Lua

lua_thread_create(state_id)

lua_call_start(state_id, name, ...arguments)

lua_call_next(state_id)

Writing Lua code

FAQ

Limitations

Lua Tutorial

Lua Basics Tutorial

Lua Advanced

Lua Libraries

Lua Useful Resources

Selected Reading

Let us start creating our first Lua program!

First Lua Program

Interactive Mode Programming

Lua provides a mode called interactive mode. In this mode, you can type in instructions one after the other and get instant results. This can be invoked in the shell by using the lua -i or just the lua command. Once you type in this, press Enter and the interactive mode will be started as shown below.

You can print something using the following statement −

Once you press enter, you will get the following output −

Default Mode Programming

Invoking the interpreter with a Lua file name parameter begins execution of the file and continues until the script is finished. When the script is finished, the interpreter is no longer active.

Let us write a simple Lua program. All Lua files will have extension .lua. So put the following source code in a test.lua file.

Assuming, lua environment is setup correctly, let’s run the program using the following code −

We will get the following output −

Let's try another way to execute a Lua program. Below is the modified test.lua file −

Here, we have assumed that you have Lua interpreter available in your /usr/local/bin directory. The first line is ignored by the interpreter, if it starts with # sign. Now, try to run this program as follows −

We will get the following output.

Let us now see the basic structure of Lua program, so that it will be easy for you to understand the basic building blocks of the Lua programming language.

Tokens in Lua

A Lua program consists of various tokens and a token is either a keyword, an identifier, a constant, a string literal, or a symbol. For example, the following Lua statement consists of three tokens −

The individual tokens are −

Comments

Comments are like helping text in your Lua program and they are ignored by the interpreter. They start with --[[ and terminates with the characters --]] as shown below −

Lua Cheat Sheet Pdf

Identifiers

A Lua identifier is a name used to identify a variable, function, or any other user-defined item. An identifier starts with a letter ‘A to Z’ or ‘a to z’ or an underscore ‘_’ followed by zero or more letters, underscores, and digits (0 to 9).

Lua does not allow punctuation characters such as @, $, and % within identifiers. Lua is a case sensitive programming language. Thus Manpower and manpower are two different identifiers in Lua. Here are some examples of the acceptable identifiers −

Keywords

The following list shows few of the reserved words in Lua. These reserved words may not be used as constants or variables or any other identifier names.

and	break	do	else
elseif	end	false	for
function	if	in	local
nil	not	or	repeat
return	then	true	until
while

Whitespace in Lua

A line containing only whitespace, possibly with a comment, is known as a blank line, and a Lua interpreter totally ignores it.

Lua Tutorial

Whitespace is the term used in Lua to describe blanks, tabs, newline characters and comments. Whitespace separates one part of a statement from another and enables the interpreter to identify where one element in a statement, such as int ends, and the next element begins. Therefore, in the following statement −

There must be at least one whitespace character (usually a space) between local and age for the interpreter to be able to distinguish them. On the other hand, in the following statement −

No whitespace characters are necessary between fruit and =, or between = and apples, although you are free to include some if you wish for readability purpose.