 -- Validates that a given string `str` is a string and only contains letters.
-- Throws an error if either of these conditions is not met, with a message indicating what the problem is.
function validateEnumString(str, strType)
  if type(str) ~= "string" then
    error(strType .. " must be a string")
  end
  if str:match("[^%a]") then
    error(strType .. " must only contain letters")
  end
end

-- Creates a new table with the given `name` and `vals` as keys and values, respectively.
-- Validates that `name` and each value in `vals` are strings and only contain letters.
-- Returns the created table.
function LocalEnum(name, vals)
  validateEnumString(name, "Enum name")
  local enum = {}
  for k, v in pairs(vals) do
    if (not tonumber(k)) then
      validateEnumString(k, "Enum value")
      enum[k] = v
    else
      validateEnumString(v, "Enum value")
      enum[v] = v
    end
  end
  return enum
end

-- Creates a global variable with the given `name` and assigns it the value returned by `LocalEnum` when called with `name` and `vals` as arguments.
function Enum(name, vals)
  _G[name] = LocalEnum(name, vals)
end

Enum("VehicleColor", {
  Black = 0,
  Red = 1,
  Blue = 2,
  Green = 3,
  Purple = 4
})

print(VehicleColor.Black)

created 2 years ago

Lua online compiler

Write, Run & Share Lua code online using OneCompiler's Lua online compiler for free. It's one of the robust, feature-rich online compilers for Lua language, running the latest Lua version 5.4. Getting started with the OneCompiler's Lua editor is easy and fast. The editor shows sample boilerplate code when you choose language as Lua and start coding.

Taking inputs (stdin)

OneCompiler's Lua online editor supports stdin and users can give inputs to programs using the STDIN textbox under the I/O tab. Following is a sample Lua program which takes name as input and prints hello message with your name.

name = io.read("*a")
print ("Hello ", name)

About Lua

Lua is a light weight embeddable scripting language which is built on top of C. It is used in almost all kind of applications like games, web applications, mobile applications, image processing etc. It's a very powerful, fast, easy to learn, open-source scripting language.

Syntax help

Variables

By default all the variables declared are global variables
If the variables are explicitly mentioned as local then they are local variables.
Lua is a dynamically typed language and hence only the values will have types not the variables.

Examples

-- global variables
a = 10

-- local variables

local x = 30

Value Type	Description
number	Represents numbers
string	Represents text
nil	Differentiates values whether it has data or not
boolean	Value can be either true or false
function	Represents a sub-routine
userdata	Represents arbitary C data
thread	Represents independent threads of execution.
table	Can hold any value except nil

Loops

1. While:

While is also used to iterate a set of statements based on a condition. Usually while is preferred when number of iterations are not known in advance.

while(condition)
do
--code
end

2. Repeat-Until:

Repeat-Until is also used to iterate a set of statements based on a condition. It is very similar to Do-While, it is mostly used when you need to execute the statements atleast once.

repeat
   --code
until( condition )

3. For:

For loop is used to iterate a set of statements based on a condition.

for init,max/min value, increment
do
   --code
end

Functions

Function is a sub-routine which contains set of statements. Usually functions are written when multiple calls are required to same set of statements which increase re-usuability and modularity.

optional_function_scope function function_name( argument1, argument2, argument3........, argumentn)
--code
return params with comma seperated
end