[Bug] irb does not allow me to overwrite irb's core methods #839
Description
irb comes with some built in methods such as "ls".
When I type "ls" I get this dropdown menu result:
https://i.imgur.com/MHoICC9.png
When I then try to re-define ls as a method, irb ignores it:
https://i.imgur.com/Bp0xGcV.png
Meaning, when I then type "ls" again, my own custom
defined method is ignored, and the built-in is called,
which leads to the dropdown menu shown in the first
image on imgur.
The input I used for the method definition in the second image
was as follows:
ls
def ls
puts 'OK'
end
ls
This was on a vanilla IRB.
I believe this is a change to prior IRB versions. In older IRB versions,
I think, we could re-define such methods without a problem. With
the rewrite of irb, we no longer can.
I believe that this functionality is a bug, not solely because it modified
the old behaviour, but more importantly because irb should test RUBY's
default behaviour, and in a .rb file I can define a method called "ls" just
fine, without irb interfering. So I believe this is a bug both in behaviour,
as well as in intent.
How would I propose to change this?
Well, I believe it is ok if you want to make "ls" as a default behaviour
available - but NOT if you ignore and prevent the user from defining
a method called "ls" (or any other in-built method - see my other
prior bug report). The latter I consider behaviour that should not
happen.
As a compromise the proper way to handle this is to perhaps show
a warning (optionally also allow to disable this warning somehow),
but to allow the user to re-define that behaviour. Internally you can
always use methods such as "ls" as "irb_ls" or some variant nobody
accidentally types.
At the least I would expect that irb documents such changes, because
to me it was super-surprising to find out that my old ruby code does
not work, when it really should work. Took me a while to change it.
PS: I also changed my old code and specifically avoid calling irb's
in-built methods, so although I think irb's new behaviour is wrong,
it no longer affects me as I adjusted my own code base. Still I find
it rather questionable how irb suddenly changes after some 15
years or so. Either way I did report it now - what then happens is
no longer up to me. Thanks for reading this report nonetheless.