Let's say I'm using irb, and type a = 5. How do I remove the definition of a so that typing a returns a NameError?
Some context: later I want to do this:
context = Proc.new{}.binding
context.eval 'a = 5'
context.eval 'undef a' # though this doesn't work.
There are remove_class_variable, remove_instance_variable and remove_const methods but there is currently no equivalent for local variables.
Currently you have no mean to remove global variables, local variables and class variables. You can remove constants using "remove_const" method though
In the spirit of the question, you could limit the variable to a scope, assuming you are okay with other local variables being locked to the same scope. This is useful particularly if you are defining something in a class and don't want the local variable to stay around in the class declaration.
The only ways I can think to do this is with Integer#times or Array#each like so:
1.times do |a|
a = 5
# code…
end
[5].each do |a|
# code…
end
There are probably other, even cleaner ways to limit to a block besides this. These aren't as clean as I'd like and I'd love to see if someone has a cleaner method to use to do this.