Hi Robert!
s.class.class_eval %q(def x.says() puts “x
says:”+self
end)
This doesn’t work for me. You define a method “say”
for an instance “x”
in the scope of the class. You probably want
something else.
I noticed that I made a mistake there and correct it
on another email few seconds after that one. Sorry
about that. My fault.
As I told on the other email, the correct thing is
s.class.class_eval %q(def s.says() puts “s says:”+self
end)
So I create a method “says” only on the object s (not
on the class String where it belongs to).
It would certainly help if you tell us what problem
you are trying to solve.
Ok, not really a problem, I was just curious about it.
Let’s imagine that I need a way to create methods on
specific objects, not on their classes. The methods
are stored on some file or the user type it when using
the program (ok, I know the security concerns about
that :-), and I find them later using some reflection
and respond_to calls.
So at some point the user knows (again, don’t know if
its a valid situation) that there are some String
objects hangin’ there, s and x, and says “hey, add
this method I defined here on this text field, as a
string, to the s object, but just to it, not to its
class or other String objects”. On this case, knowing
that I want to create the method just on s, and it’s a
String, I can use
String.class_eval %q(def s.says() puts “s says:”+self
end)
to make this works, and ask for some reavaliation of
the current objects, where it will tell me that the s
object, yes, have a “says” method there.
s.respond_to?(:says)
It works this way, I was just curious if there is not
an object method to do that, not using the class to
make it works. But works this way because of the need
to add a virtual class to s to hold the says() method,
right?
Best regards,
