ruby catch-throw and efficiency

Question

catch in Ruby is meant to jump out of deeply nested code. In Java e.g. it is possible to achieve the same with Java's try-catch meant for handling exceptions, it is however considered poor solution and is also very inefficient. In Ruby for handling exceptions we have begin-raise-rescue and I assume it is also to expensive to use it for other tasks.

Is Ruby's catch-throw really a more efficient solution then begin-raise-rescue or are there any other reasons to use it to break nested blocks instead of begin-raise-rescue?

Answer 1

In addition to being the "correct" way to get out of control structures, catch-throw is also significantly faster(10 times as fast in my testing). Check out this gist for my code and results.

Answer 2

Josh's answer is correct. I want to add more information about catch-throw and raise-rescue.

catch-throw is used for flow control whereas raise-rescue is used for exception/error handling. The different is: backtrace is not needed for catch-throw (flow control). Trust me, the main reason causes raise-rescue runs slow than catch-throw 10 times in Josh's gist is raise-rescue takes a lot time to create backtrace object.

If you want to raise without backtrace, use syntax:

raise <type>, <message>, <backtrace>

Checkout my gist. raise without backtrace is much faster than raise with backtrace.

April 2016 Update:

I've updated my gist:

• Fixed "break" test
• Added benchmark tests results for newer ruby version 2.1.8, 2.2.4, 2.3.0