moonscript/moonscript.lua

module("moonscript", package.seeall)

require"util"
require"lpeg"

require"moonscript.compile"

local R, S, V, P = lpeg.R, lpeg.S, lpeg.V, lpeg.P
local C, Ct = lpeg.C, lpeg.Ct

local Space = S" \t"^0
local Indent = S"\t"^0
local Break = S"\n" + -1
local ArgDelim = "," * Space

local Name = C(R("az", "AZ", "__") * R("az", "AZ", "__")^0) * Space
local Num = C(R("09")^1) / tonumber * Space

local FactorOp = lpeg.C(S"+-") * Space
local TermOp = lpeg.C(S"*/%") * Space

function wrap(fn)
	local env = getfenv(fi)

	return setfenv(fn, setmetatable({}, {
		__index = function(self, name)
			local value = env[name] 
			if value ~= nil then return value end

			if name:match"^[A-Z][A-Za-z0-9]*$" then
				local v = V(name)
				rawset(self, name, v)
				return v
			end
			error("unknown variable referenced: "..name)
		end
	}))
end

function mark(name)
	return function(...)
		return name, ...
	end
end

function flatten(tbl)
	if #tbl == 1 then
		return tbl[1]
	end
	return tbl
end


local build_grammar = wrap(function()
	local g = lpeg.P{
		Block,
		Block = Ct(Line^0),
		Line = Ct(Funcall) * Break,
		Funcall = Name * ArgList / mark"fncall",
		ArgList = Ct(Exp * (ArgDelim * Exp)^0),
		Exp = Ct(Value * (FactorOp * Value)^0) / flatten,
		Value = Funcall + Num + Name
	}
	return Space * g * Space * -1
end)

local grammar = build_grammar()

local program = [[
hello world nuts
eat 232, 343
]]
-- print hi + world + 2342
-- print 23424
-- ]]


local tree = grammar:match(program)
if not tree then error("failed to compile") end

print(util.dump(tree))
print(compile.tree(tree))

local program2 = [[
if something
	print 1
else
	print 2
]]

local program2_ = [[
if something
{ print 1
} else
{ print 2
}
]]

local program3 = [[
class Hello
	@something = 2323

	hello: () ->
		print 200
]]

local program3 = [[
class Hello
{ @something = 2323
  hello: () ->
  { print 200
}}
]]

function names()
	tests = {
		"hello",
		"23wolrld",
		"_What343"
	}

	for _, v in ipairs(tests) do
		print(Name:match(v))
	end
end