pico8-to-lua

A command-line utility written in Lua that converts the PICO-8 variety of extended Lua syntax to standard Lua syntax.

It’s a thin wrapper around the internal syntax converter from PICOLOVE.

Reasons you might find this useful:

• You want to run a tool built for Lua on your code, and the tool won’t recognize it because you’re using special PICO-8 syntax
• You want better syntax highlighting support in your text editor
• You want to extract a function you wrote for PICO-8 and use it in a different Lua program

You might also try…

While I was working on this project, picotool was updated to support a --pure-lua argument to its listlua command, which will do roughly the same thing as this!

Installation

1. Install Lua for your operating system. This doesn’t come with PICO-8, which has its own Lua compiler, so you’ll need to install Lua separately.

2. You can either:

   a. Install with LuaRocks:

    $ luarocks install pico8-to-lua

   b. Clone the repository from GitHub and enter the project directory:

    $ git clone https://github.com/benwiley4000/pico8-to-lua.git
    $ cd pico-to-lua/

Usage

NOTE: All the examples assume you have installed pico-to-lua globally, but if you’re using it from inside the cloned directory, you can replace all instances of pico8-to-lua with ./pico8-to-lua.lua (or lua pico8-to-lua.lua for non-UNIX environments) in the commands that you run.

Assuming you have an input Lua file that looks like this:

-- input.lua
function next_even_number(num)
 if (num % 2 != 0) num += 1
 return num
end

You can generate a standard Lua version with the command:

$ pico8-to-lua input.lua

You should see this output:

function next_even_number(num)
 if num % 2 ~= 0 then num = num +  1 end
 return num
end

You can also use a .p8 file as input…

pico-8 cartridge // http://www.pico-8.com
version 16
__lua__
function _init()
 local num = 0b10
 if (num+1==0b11) print('yes!')
end

$ pico8-to-lua input.p8

…which will output transformed p8 file contents:

pico-8 cartridge // http://www.pico-8.com
version 16
__lua__
function _init()
 local num = 0x2
 if num+1==0x3 then print('yes!') end
end

If you only want the lua output, you can pass the --lua-only flag when the input is a p8 file:

$ pico8-to-lua input.p8 --lua-only

function _init()
 local num = 0x2
 if num+1==0x3 then print('yes!') end
end

If you’re in a UNIX environment, you can pipe the output directly to a file:

$ pico8-to-lua input.lua > output.lua

$ pico8-to-lua input.p8 > output.p8

Or you can pipe into another program:

$ pico8-to-lua input.p8 --lua-only | luacheck -

You can even pipe output from another program into this one by passing - as the filename argument:

$ cat input.lua | pico8-to-lua - > output.lua

$ curl https://someurl.com/mycart.p8 | pico8-to-lua - --lua-only | luacheck -