7 ms·
What's New in Ruby 2.1 [pdf]
- conorh 13y agoI really like the ObjectSpace.trace_object_allocations addition. I had a quick look at the 2.1 docs for ObjectSpace and there seem to be all sorts of interesting methods in there reachable_objects_from(obj) and memsize_of(obj) for example. It looks like understanding memory usage and tracking down memory leaks will get a lot easier with 2.1. http://ruby-doc.org/stdlib-2.1.0/libdoc/objspace/rdoc/ObjectSpace.html#method-c-trace_object_allocations http://ruby-doc.org/stdlib-2.1.0/libdoc/objspace/rdoc/Object...
- matsadler 13y ago#reachable_objects_from was added in 2.0, and I think #memsize_of was introduced in one of the 1.9 releases. The documentation is new though. I wrote a little about them here: http://globaldev.co.uk/2013/03/ruby-2-0-0-in-detail/#id6 http://globaldev.co.uk/2013/03/ruby-2-0-0-in-detail/#id6
- conorh 13y agoAh nice, thanks, missed the part about requiring "objspace" to mix them in and assumed they would be on the already existing ObjectSpace module.
- taylorfausak 13y agoI'm looking forward to `def` returning a symbol (page 11). private static void def main(args) ...; end
- ngcazz 13y agoThat slide was a bit confusing for my underslept mind. Is that meant as an example of calling methods which work over the result of defining main (in this case static and void)?
- lectrick 13y agoIf you say "private def methodname(args); end", the "private" keyword already takes a symbol for a method name to privatize, so in this case the return of "def methodname(args); end" is ":methodname" which then gets passed to "private" and everything magically works.
- hderms 13y agoyeah it's an example of how you could implement higher-level language features much easier if def returns a symbol rather than nil
- cmaggard 13y agoIt's unclear from the intro summary, but I'm assuming from the lack of further explanation that refinements are just GONE, and not just "no longer experimental"?
- jameskilton 13y agoNope, by "no longer experimental" they are now officially in the core language. More information here: http://rkh.im/ruby-2.1 http://rkh.im/ruby-2.1
- cmaggard 13y agoAh, well that's something then. Thanks for the clarification.
- danso 13y agoEverytime I read a Ruby version announcement/explanation, it reminds me that I've been a coder working and thinking exclusively in English, but my current programming language of choice is prominently steered by non-English speakers...and somehow things work pretty peachy. But it always makes me wonder how much more in-depth and richer the discussion of Ruby amongst its Japanese maintainers, before they translate it for us in English?
- steveklabnik 13y agoYou can subscribe to ruby-dev and find out. ;) It's actually much more low-traffic than ruby-core, and someone has volunteered to translate any email if you ask.
- thinkbohemian 13y agoKoichi is gives some of the best presentations. It is hard enough to be funny in one language, yet to be funny and understandable in two is quite an accomplishment. If you're ever at a Rubyconf, go to his talks. Also love the speed work he's been doing with generational GC. For a primer, Pat Shaughnessy has a great talk you should check out, also Ruby Under a Microscope is a good dive into Ruby.
- dylandrop 13y agoCan someone explain the "write barrier" stuff? It's hard to glean what the problem is that they're solving here... And what they're saying about Arrays, Strings, Hash, etc, in relation to WB protected vs. WB unprotected.
- matsadler 13y agoI've not read the code, so someone may have to correct me, but I think this is the gist of it: Ruby 2.1 introduces a generational garbage collector, this divides all objects into young and old generations. A regular GC run will only look at the young generation, with the old being collected less frequently. An object is promoted to the old generation when it survives a young generation run. If you have objects in the old generation referring objects in the young generation, but you're only looking at the young generation it may seem like an object doesn't have any references, and you might incorrectly GC an in-use object. Write barriers prevent this by adding old generation objects to a 'remember set' when they are modified to refer to a young generation object (eg old_array.push(young_string)). This 'remember set' is then taken in to account when collecting the young generation. Most generational garbage collectors need these write barriers on all objects, but with the many 3rd party C extensions available for Ruby this isn't possible, so a workaround was devised whereby objects that aren't write barrier protected won't ever be promoted to the old generation. This isn't ideal as you won't get the full benefit of the generational GC, but it does maximise backwards compatibility.
- Slackwise 13y agoI'm uncertain why they've added an `f` suffix for frozen string literals/instantiation. I can understand needing to freeze an existing String, but you can do that with Object#freeze, but a literal syntax seems to overlap with the usage of Symbols. The only benefit I can think of is not needing to use Symbol#to_s when working alongside strings. I'm not saying frozen strings are not useful, because they can be after taking in some input/params to work with/store, but a literal syntax seems extremely edge-case-y. Now instead of "foo".freeze it's "foo"f, but how frequently will that save you time/trouble? The bigger implication is that slides 23/24 shows that immutable strings and symbols will share their heap locations, if I'm reading the diagrams correctly, but have different object_ids. This seems a bit bewildering and focused on micro-optimization, which is not the mental model I have in mind when I'm coding in a very high level language. It's also blurring the semantic difference between Symbols and Strings.
- jamesbritt 13y agoNow instead of "foo".freeze it's "foo"f, but how frequently will that save you time/trouble? Worse, it seems to break the model of "interact with objects by sending messages", where you send a message using <object>.<message> Is "foo"f _not_ sending a message? If so, then what is it doing? If yes, then why new syntax?
- bct 13y agoIt's not sending a message - that would defeat the purpose. It's constructing a frozen string, reusing an existing one when possible. Prior to 2.1: def foo "bar".freeze end does these things every time `foo` is called: 1. copies the characters 'b', 'a', and 'r' into a mutable string 2. sends the message `freeze` to the new string, which... 3. marks the string as frozen. In 2.1 `"bar".freeze` is equivalent to `"bar"f`, which will not make a copy every time `foo` is called. See https://bugs.ruby-lang.org/issues/8579 https://bugs.ruby-lang.org/issues/8579 for more discussion.
- jamesbritt 13y agoI see. Thank you.
- andyl 13y agoI've upgraded one of my Rails4 apps to 2.1.0-preview2. Everything seems to be working fine except pry-debugger. What is it with the ruby debugger? It has always been problematic for me.
- thedevelopment 13y agoI believe the debugger is broken in Ruby-2.0, and you should use byebug instead. There are pry wrappers for byebug - https://github.com/deivid-rodriguez/pry-byebug https://github.com/deivid-rodriguez/pry-byebug - maybe that'll work?
- andyl 13y agoYesss - that worked. Tip of the day - thanks a ton !!
- diminish 13y agoI wish they dedicate 2.2 and 2.3 only to performance improvements of the core and std lib.
- ksec 13y agoYes, JIT to Native Code, Better GC. We have yet to see any "substantial" improvement.
- dgregd 13y agoIs it possible to add optional typing to Ruby? Something similar to what Dart has. Optional typing would be very useful for big Ruby apps.
- rev_null 13y agoI'd be intrigued to see how a ruby type checker would handle boolean expressions.
- venus 13y agoThe most important feature for me is mandatory named args: def foo(bar:) Named args with defaults solved one half of the problem we'd been solving with the "options hash"; now that's the second half. Can't wait!