On: Tail Calls, Optimization, and ES6

[yror10]

If you write ruby and want TCO put this at the top of your .rb file:

    RubyVM::InstructionSequence.compile_option = {
      :tailcall_optimization => true,
      :trace_instruction => false
    }

[eknkc → yror10]

Why is it optional? What is the benefit of having it disabled by default if there is a decent implementation?

[anonova → eknkc]

They disabled it for error reporting/debugging reasons. Because you don't need to create a new stack frame, you eliminate that information in the backtrace.

[steveklabnik → anonova]

I've seen at least one paper that shows a way to fix this... hm.

[Tuna-Fish → eknkc]

A lot of people prefer having complete, explicit stacks for debugger use over having tail calls.

[hajile → Tuna-Fish]

loops don't leave a stack trace either...

[damncabbage → yror10]

And also apply this patch, if you're using MRI (the C implementation, and the most common Ruby runtime): https://gist.github.com/plexus/11201946