example.bit

package:application/vnd.bitty-archive;
data:text/lua;count=1632;path=bf/compiler.lua;
--[[
BF compiler for the Bitty Engine

Copyright (C) 2020 - 2021 Tony Wang, all rights reserved

Homepage: https://paladin-t.github.io/bitty/
]]

-- Based on https://github.com/prapin/LuaBrainFuck.
local interpreter = 'local output = \'\'\n' ..
	'local input_ = function()\n' ..
	'	local i = input()\n' ..
	'	return i and i:byte(1) or 0\n' ..
	'end\n' ..
	'local function interpret(s)\n' ..
	'	local subst = {["+"]="v=v+1 ", ["-"]="v=v-1 ", [">"]="i=i+1 ", ["<"]="i=i-1 ",\n' ..
	'		["."] = "w(v)", [","]="v=r()", ["["]="while v~=0 do ", ["]"]="end "}\n' ..
	'	local env = setmetatable({ i=0, t=setmetatable({},{__index=function() return 0 end}),\n' ..
	'		r=function() return input_() end, w=function(c) output=output..string.char(c) end },\n' ..
	'		{__index=function(t,k) return t.t[t.i] end, __newindex=function(t,k,v) t.t[t.i]=v end })\n' ..
	'	load(s:gsub("[^%+%-<>%.,%[%]]+",""):gsub(".", subst), "brainfuck", "t", env)()\n' ..
	'	print(output)\n' ..
	'end\n'

-- Compiles from an asset.
function compile(asset)
	if not asset then
		error('Invalid asset.')
	end

	local bytes = Project.main:read(asset)
	if not bytes then
		error('Invalid asset.')
	end
	bytes:poke(1)

	local src = bytes:readString()
	local dst = ''
	for ln in src:gmatch('([^\n]*)\n?') do
		if #ln > 0 then
			local comment = ln:find('#')
			if comment then
				ln = ln:sub(1, comment - 1) -- Remove comment.
			end
			dst = dst .. ln                 -- Concat lines.
		end
	end
	local full = interpreter .. 'interpret(\'' .. dst .. '\')' -- Link the source code with the interpreter together.

	return load(full) -- Return loaded and parsed Lua chunk.
end

data:text/txt;count=96;path=bf/README.txt;
# BF compiler for Bitty Engine

Usage:
  require 'bf/compiler'
  f = compile('source.bf')
  f()

data:binary/octet;count=231;path=hello world.bf;
++++++++++[>+++++++>++++++++++>+++>+<<<<-]>++.>+.+++++++..+++.>++.<<+++++++++++++++.>.++ # The BF compiler supports new lines,
+.------.--------.>+.>.                                                                  # and comments.
data:text/json;count=206;path=info.json;
{
  "id": 0,
  "title": "BF Example",
  "description": "A BF example project.",
  "author": "Tony",
  "version": "1.0",
  "genre": "TUTORIAL",
  "url": "https://github.com/paladin-t/bitty.compiler_plugin"
}
data:binary/octet;count=6;path=input.bf;
,.,.,.
data:text/lua;count=183;path=main.lua;
require 'bf/compiler'               -- Require the compiler.

local f = compile('hello world.bf') -- Compile something.
f()                                 -- Run the compiled chunk.