local ipairs, setmetatable, tostring, print
    = ipairs, setmetatable, tostring, print

local minetest, vector
    = minetest, vector

local mod_name = minetest.get_current_modname()

local utility = {}

-- Prints an error message by concatenating the parameters as strings.
function error(...)
    local str = "[" .. mod_name .. "] "
    for _, v in ipairs({...}) do str = str + tostring(v) end
    print(str)
end
utility.error = utility

if not vector.convert then
    function vector.convert(v)
        local t = type(v)
        if t == "number" then
            -- Assume the number was created by calling `vector.hash`.
            return setmetatable(minetest.get_position_from_hash(v), vector.metatable)
        elseif t == "string" then
            -- Assume the string is either in `(x, y, z)` or `{x=x, y=y, z=z}` format.
            local first_chr = v:byte(1)
            if     first_chr == "(" then return vector.from_string(v)
            elseif first_chr == "{" then return setmetatable(minetest.deserialize(v), vector.metatable)
                                    else error("Cannot convert string '" .. v .. "' to vector") end
        elseif t == "table" then
            -- Assume the table already has `x`, `y` and `z` entries.
            -- Returns the same table, making sure its metatable is set.

            return setmetatable(v, vector.metatable)
        else error("Cannot convert type '" .. t .. "' to vector") end
    end
end

if not vector.hash then
    function vector:hash()
        return minetest.hash_node_position(self)
    end
end

return utility