From: "ioquatix (Samuel Williams)" Date: 2021-08-19T01:00:21+00:00 Subject: [ruby-core:104984] [Ruby master Feature#18083] Capture error in ensure block. Issue #18083 has been updated by ioquatix (Samuel Williams). Your proposed "shorter and easier to understand" implementation is actually incorrect: ``` def transaction1 begin yield rescue Exception => error ensure if error puts "abort" else puts "commit" end end end def transaction2 begin yield rescue Exception puts "abort" else puts "commit" end end catch(:foo) do transaction1 do throw :foo end end ``` Try for `transaction1` and `transaction2`. The flow control is wrong for `transaction2`. ---------------------------------------- Feature #18083: Capture error in ensure block. https://bugs.ruby-lang.org/issues/18083#change-93384 * Author: ioquatix (Samuel Williams) * Status: Open * Priority: Normal ---------------------------------------- As discussed in https://bugs.ruby-lang.org/issues/15567 there are some tricky edge cases. As a general model, something like the following would be incredibly useful: ``` ruby begin ... ensure => error pp "error occurred" if error end ``` Currently you can get similar behaviour like this: ``` ruby begin ... rescue Exception => error raise ensure pp "error occurred" if error end ``` The limitation of this approach is it only works if you don't need any other `rescue` clause. Otherwise, it may not work as expected or require extra care. Also, Rubocop will complain about it. Using `$!` can be buggy if you call some method from `rescue` or `ensure` clause, since it would be set already. It was discussed extensively in https://bugs.ruby-lang.org/issues/15567 if you want more details. -- https://bugs.ruby-lang.org/ Unsubscribe: