Ruby Quiz number 67 (metakoans)
I just finished my first rubyquiz. Yay. I take a look every now and then but never seem to find the time to spend on them.
I made the time for metakoans as it involved ‘meta-programming’ which I’ve recently spent some time on at work
My solution is here, and although it passes all the tests of the quiz it’s probably not great as this stuff still confuses me somewhat. I didn’t take a look at any other solutions (although I will shortly) so any similarity is coincidental.
class Object
def attribute(arg, &block)
if arg.class == Hash
attribute = arg.keys[0]
value = arg.values[0]
else
attribute = arg
value = block ? block : nil
end
class_eval do
attr_writer attribute
define_method(attribute) do
unless instance_variable_get("@#{attribute}")
default_value = (value.class == Proc) ? instance_eval(&value) : value
instance_variable_set("@#{attribute}", default_value)
end
instance_variable_get("@#{attribute}")
end
define_method("#{attribute}?") do
instance_variable_get("@#{attribute}") ? true : false
end
end
end
end
