Question

I’d like to do something like this in ruby:

safe_variable = begin
  potentially_nil_variable.foo
rescue
  some_other_safe_value
end

… and treat the exception block (begin/rescue/end) as a function/block. This doesn’t work as written, but is there a way to get a similar result?

NB what I’m actually doing is this, which works but is IMO ugly:

begin
  safe_variable = potentially_nil_variable.foo
rescue
  safe_variable = some_other_safe_value
end

UPDATE

I guess I hit a corner case on ruby syntax. What I actually was doing was this:

object_safe = begin potentially_nil_variable.foo
rescue ""
end

The error was class or module required for rescue clause. Probably it thought that "" was supposed to be the placeholder for the exception result.

Answer 1

The form you have should work:

safe_variable = begin
  potentially_nil_variable.foo
rescue
  some_other_safe_value
end

A shorter form:

safe_variable = this_might_raise rescue some_other_safe_value

If you’re only avoiding nil, you can look into ActiveRecord’s try:

safe_variable = potentially_nil_variable.try(:foo) || some_other_safe_value