Configuration API

--[[
The MIT License (MIT)

Copyright (c) 2014 Lyqyd

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
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The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

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--]]

function load(path, _env)
    --load a configuration file, given a fully-resolved path and an optional environment.
    if not fs.exists(path) or fs.isDir(path) then return nil, "not a file" end
    local env
    if not _env then
        --if we were not provided an environment, create one.
        env = setmetatable({}, {__index = _G})
    else
        env = _env
    end
    local fn, err = loadfile(path)
    if fn then
        setfenv(fn, env)
        local success, err = pcall(fn)
        if success then
            --strip the metatable from the environment before returning it.
            return setmetatable(env, {})
        else
            return nil, err
        end
    else
        return nil, err
    end
end

function save(path, config)
    if not config or type(config) ~= "table" then return nil, "Not a configuration" end
    local handle = io.open(path, "w")
    if handle then
        for k, v in pairs(config) do
            local success, str = pcall(textutils.serialize, v)
            if success then
                handle:write(k.." = "..str.."\n\n")
            end
        end
        handle:close()
    else
        return nil, "Could not write configuration."
    end
end