Macro Thinger

local macros = {
    ["@"] = {
        pat = "@(%b())";
        fn = function(_f)
            local f = _f:sub(2, -2)
                        :gsub("@0", "a")
                        :gsub("@(%d)", "a[%1]")
                        :gsub("@", "return ")
            return "(function(...) local a = {...} "..f.." end)"
        end;
    };
    ["$"] = {
        add = [[
                local get_file_macro = setmetatable({}, {
                    __index = function(self, _k)
                        if not fs.exists(_k) then
                            fs.open(_k, "w").close()
                        end
                        local h = fs.open(_k, "r")
                        local text = h.readAll()
                        h.close()
                        return text
                    end;
                    __newindex = function(self, _k, _v)
                        if type(_v) == "string" then
                            local h = fs.open(_k, "w")
                            h.write(_v)
                            h.close()
                        end
                    end;
                })
            ]];
        pat = "$(%b())";
        fn = function(_f)
            local f = _f:sub(2, -2)
            return "get_file_macro["..f.."]"
        end;
    };
}
return function(_str, ...)
    local str, arg = _str, {...}
    for macro in _str:gmatch("#macro%s+(%S+)") do
        local use_macro = macros[macro]
        str = (use_macro.add or "")..str
        if use_macro.pat and use_macro.fn then
            str = str:gsub(use_macro.pat, use_macro.fn)
        end
    end
    return str
end