local msg = require 'mp.msg' -- converts val to type of desttypevallocal function typeconv(desttypeval, val)    if type(desttypeval) == "boolean" then        if val == "yes" then            val = true        elseif val == "no" then            val = false        else            msg.error("Error: Can't convert '" .. val .. "' to boolean!")            val = nil        end    elseif type(desttypeval) == "number" then        if tonumber(val) ~= nil then            val = tonumber(val)        else            msg.error("Error: Can't convert '" .. val .. "' to number!")            val = nil        end    end    return valend -- performs a deep-copy of the given option valuelocal function opt_copy(val)    return val -- no tables currentlyend -- compares the given option values for equalitylocal function opt_equal(val1, val2)    return val1 == val2end -- performs a deep-copy of an entire option tablelocal function opt_table_copy(opts)    local copy = {}    for key, value in pairs(opts) do        copy[key] = opt_copy(value)    end    return copyend  local function read_options(options, identifier, on_update)    local option_types = opt_table_copy(options)    if identifier == nil then        identifier = mp.get_script_name()    end    msg.debug("reading options for " .. identifier)     -- read config file    local conffilename = "script-opts/" .. identifier .. ".conf"    local conffile = mp.find_config_file(conffilename)    if conffile == nil then        msg.debug(conffilename .. " not found.")        conffilename = "lua-settings/" .. identifier .. ".conf"        conffile = mp.find_config_file(conffilename)        if conffile then            msg.warn("lua-settings/ is deprecated, use directory script-opts/")        end    end    local f = conffile and io.open(conffile,"r")    if f == nil then        -- config not found        msg.debug(conffilename .. " not found.")    else        -- config exists, read values        msg.verbose("Opened config file " .. conffilename .. ".")        local linecounter = 1        for line in f:lines() do            if line:sub(#line) == "\r" then                line = line:sub(1, #line - 1)            end            if string.find(line, "#") ~= 1 then                local eqpos = string.find(line, "=")                if eqpos ~= nil then                    local key = string.sub(line, 1, eqpos-1)                    local val = string.sub(line, eqpos+1)                     -- match found values with defaults                    if option_types[key] == nil then                        msg.warn(conffilename..":"..linecounter..                            " unknown key '" .. key .. "', ignoring")                    else                        local convval = typeconv(option_types[key], val)                        if convval == nil then                            msg.error(conffilename..":"..linecounter..                                " error converting value '" .. val ..                                "' for key '" .. key .. "'")                        else                            options[key] = convval                        end                    end                end            end            linecounter = linecounter + 1        end        io.close(f)    end     --parse command-line options    local prefix = identifier.."-"    -- command line options are always applied on top of these    local conf_and_default_opts = opt_table_copy(options)     local function parse_opts(full, opt)        for key, val in pairs(full) do            if string.find(key, prefix, 1, true) == 1 then                key = string.sub(key, string.len(prefix)+1)                 -- match found values with defaults                if option_types[key] == nil then                    msg.warn("script-opts: unknown key " .. key .. ", ignoring")                else                    local convval = typeconv(option_types[key], val)                    if convval == nil then                        msg.error("script-opts: error converting value '" .. val ..                            "' for key '" .. key .. "'")                    else                        opt[key] = convval                    end                end            end        end    end     --initial    parse_opts(mp.get_property_native("options/script-opts"), options)     --runtime updates    if on_update then        local last_opts = opt_table_copy(options)         mp.observe_property("options/script-opts", "native", function(_, val)            local new_opts = opt_table_copy(conf_and_default_opts)            parse_opts(val, new_opts)            local changelist = {}            for k, v in pairs(new_opts) do                if not opt_equal(last_opts[k], v) then                    -- copy to user                    options[k] = opt_copy(v)                    changelist[k] = true                end            end            last_opts = new_opts            if next(changelist) ~= nil then                on_update(changelist)            end        end)    end end -- backwards compatibility with broken read_options export_G.read_options = read_options return {    read_options = read_options,}