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Video equipment rental costs paid for by Peep Code Screencasts.
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Um, okay. My name is Bruce Williams. I'm going to be talking about the next Ruby, which is Ruby 1.9.
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First of all, to give you a little bit of background on me, that's my name in big red letters at the top.
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I live here in Austin, Texas.
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So, seriously.
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As you can tell, we have a very large and vibrant Ruby community here.
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With very small voices, the community here is growing at a pretty good rate.
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It's nice to have all of you here.
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So, you know, grab somebody from Austin if you're looking for a good restaurant or a good bar. There's plenty of both.
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I've been a Rubyist since 2001, back when you didn't make any money doing it, and it was just a lot of fun.
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Now you can make money doing it, and it's still a lot of fun.
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So that worked out really well. I'm a language tourist.
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What I mean by that is I'm a Rubyist by trade and it's my tool of choice, but I play with Erlang, Haskell, and whatever makes sense.
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Ruby has a long lineage, and we owe a lot to many languages.
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I think we should float around a bit and take a look at other languages as well.
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If you had to distill my life into a series of URLs, those would probably be it.
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That's where I blog when I blog, which is probably not as much as I should.
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You can find me on GitHub there using my name.
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I work at a company called Five Runs, which is here.
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We have the Tune Up and the managed products, which you can see to the right.
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Basically, I just annoy people and talk about what I'm eating for dinner and things like that.
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My Twitter, I can't claim there's anything useful that comes out of that.
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So why Ruby 1.9? Why care about Ruby 1.9?
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How many people here are using 1.8.6 most of the time (MRI)?
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Okay, keep your hands up. Now, if you're using 1.8.7, keep your hands up.
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How about 1.9? How about 1.9 in production?
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Dave, you don't count; you're an early, early adopter.
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Actually, recently, oh yeah, okay Dave, I guess you do count, but only because you paid.
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Ruby 1.9 recently did a poll; I don't know if any of you took part in it.
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They found a pretty good percentage of people—about 10 to 15 percent—last time I looked.
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Now the poll is gone, so I can't find it, which is perfect for me because I'm speaking about it today.
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About 10 or 15 percent are using Ruby 1.9 on a regular basis.
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Thinking back a little bit, Ruby 1.9 reminds me a lot of Ruby 1.7.
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Back when everybody was using 1.8.6, there was 1.8.7, and people played in the world of 1.7 before 1.8 came out.
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It's a little bit different now because people have businesses that rely on 1.8.
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They're a little less willing to go forward willy-nilly and grab stuff because we're very much into robust enterprise software in this community.
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However, Ruby 1.9 does a lot of good things for us.
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We get a whole bunch of new syntax and language features.
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As the next version, it's not strictly backwards compatible with 1.8.
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There are definitely some issues when you're migrating code, which I'm going to discuss.
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It definitely has better performance characteristics.
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And of course, it has more bugs; that's just the way software works.
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Although, it's probably easier to maintain these days.
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What I am going to talk about is the new syntax and language features because that's what I really enjoy.
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I am going to talk about migrating stuff over; I'm not going to talk about performance.
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That's something that you can find loads of numbers about from the people who are far smarter than me.
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1.9, as a whole, is much, much faster than MRI 1.8.
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I'm not going to talk about the bugs that exist besides the ones that have immediately popped up to me.
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Because I'm not psychic, I don't know where they are.
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If I were, I would be helping Mats fix them, but that's not the case.
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So, still on the thread of things I'm not going to talk about: I'm not going to talk about the other implementations of Ruby.
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Most of which target 1.8, anyway, with the exception of Mac Ruby, which has the benefit of sitting on top of 1.9.
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I'm going to be talking about YAR, so Yet Another Ruby.
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Just the plain vanilla Ruby. Not that I'm not excited about those other implementations.
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So clearly, don't go out and grab 1.9 right now; this is where you would go to grab it.
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Ruby 1.9 is in Subversion these days. I think 1.8 is a branch as well that you can track.
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It's a version if you want to get it; it's still changing on a regular basis.
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Certainly more stable than it used to be.
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The klaxon I guess was because it used to be very unstable.
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You can get 1.9 directly from the downloads page or from Subversion, and that's essentially how you build it.
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Make sure you build it with some type of program suffix or something like that so you don't get confused about what Ruby is on your system.
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I use 1.9 as mine.
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A little bit about the standard library: I apologize for this being a little out of date.
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I've done this version of this talk a couple of times and this one didn't get updated very well.
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So there may be some stuff here that is different, but in general what you have is RubyGems.
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They are now part of the standard library. They're built-in Solar, Rake, JSON, Ripper, etc.
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Some of these may seem a little crazy; you may not know what profiler is, for instance.
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Secure Random for those of you that are Sran users is for you if you really want random.
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Here's one for you to look at, and of course the HMAC digests.
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CSV was replaced by the faster CSV implementation, which I believe we have someone to thank for.
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That's a vast improvement, and in things that have disappeared, at least the last time I looked, SOAP, Wisdom and Base64 were removed.
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So for Base64, you're going to take a look at pack and unpack.
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Now we're going to talk about risk factors: parts of your code that you're going to have a problem converting over to 1.9.
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Because you're going to do it eventually, and you should at least be looking at it.
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The first thing I’ll say is that you need tests.
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If you don't have tests now on your code, first of all, you should have tests on your code.
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You have to have tests because people at conferences will annoy you to death if you don't.
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VDD, BDD, BDD; that needs to be said at least three times in every talk.
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Because it's new and cool and life-changing.
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Actually, yeah, I like it as a concept, just not as a buzzword.
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So yeah, write tests! James Edward Gray had a great quote in a Ruby talk thread many months ago.
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He talked about when he was switching over Faster CSV to 1.9.
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He talked about the fact that there are a lot of issues you didn't realize that were there.
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Your tests really helped him find them.
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That's something I keep coming back to when I've been converting some code over.
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If I didn't have my tests, it would be a lot harder to find these things.
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With Ruby, obviously, you're not going to find some bugs unless some branches of code are being executed.
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So the idea is to get those branches to execute, and tests are the way to do that.
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This is a really big change in 1.9: text processing.
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If you're writing parsers, Faster CSV is a good example of this kind of stuff.
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Regal parsers for instance, and Hpricot and Mongrel, etc., are good examples.
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You've got the issue now where we have new encoding support.
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Now when you're using the string sub-method and indexing into a string with a single index, you're going to get a character back.
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You're not going to get a number back, which is what most of us expected.
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That’s a thing we’ve brought up for years: yeah, when you index into a string, you get back a number.
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So that's gone now; we don't have to have that conversation with people.
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We need to convert over the code that relies on it.
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Now you can actually manage different encodings for your actual source files.
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This is kind of cool.
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Thank you very much. I wonder who that is? I have a wife and two kids, and it's during my talk.
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That's okay.
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Okay, where was I? Thank you, dear.
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Yes, encodings: we have these new encoding conventions, that's kind of an extra feature.
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You certainly do need to know about string, ord, and various unpack methods.
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Be familiar with unpack in general, and pack as well. They're very powerful.
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Now we'll look at some examples of changes in Ruby 1.8 and Ruby 1.9.
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Generally, in Ruby 1.8 to get what you see in Ruby 1.9, you do something like 0.1 or 0, 1.
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A major difference there is that it's not backward compatible at all.
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The recommended approach for instance, for those doing regal parsers is to unpack your string into numbers.
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You can either convert one way or the other or use character or to pull stuff out.
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Next, pulling the same kind of stuff out on the left-hand side, I'm only pulling out bytes.
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So it doesn't really work nicely for me. But on the right-hand side, it actually pulls out the multi-byte character, which is nice.
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This is obviously using some encoding trickery.
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Now granted, actually typing this in TextMate with bi-directional text and trying to put an index on the end was a complete nightmare.
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So I’ve taken the string and then taken the thing next to it and sat it down.
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It looks like it should. TextMate gets a little confused by bi-directional.
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For those of you who are dying to type Arabic, your time isn't here yet.
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You see some unpacked stuff here with actually pulling out the Unicode multi-byte.
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You know; use ri unpack to see all the crazy options.
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If you do C-star, you get a bunch of crazy negatives for the Arabic word, so that's not very helpful.
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Now this is another point: this should only affect you if you're insane.
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There's this really neat trick, very clever, I always put clever in quotes.
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Because it’s a synonym for stupid.
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This kind of stuff, usually a bug, is when someone hasn't realized they're accidentally assigning to a variable that's outside the scope using a block argument.
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You see some people do crazy things, like assigning an instance variable inside a block.
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This shouldn't exist in any code you ever show anybody else.
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And you see the output difference here; the very last loop is going to assign the last yield.
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The block variable won't take place here; it’s going to shadow it.
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It'll warn you if you're using Ruby -w, which you should be.
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So you're going to want to name your variables in your blocks something different.
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If there's anything here that...
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So in a solution, just don't do that.
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We're not going to talk about arrow lambdas just yet.
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There's a way of declaring a variable as local so that you can use it inside without assigning outside.
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Just pretend that little arrow is the lambda.
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Inside of it, you can see you're reassigning d, but on the right side, you aren't because you're declaring it local.
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But you will still get the shadow warning.
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This is kind of cool; the principle of least surprises has changed.
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Hash select now returns hashes, which is nice.
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You don't get an array of arrays, which I used to just flatten and splat to a hash.
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So you're creating an array and making a hash, which follows the principle that when you do a select it should return a hash.
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You probably could remove code to migrate this code since you're generating a hash again.
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You might be expecting arrays back and doing other things with it, so be careful.
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You see, if you had a hash called conferences, you could select on it and pull stuff out.
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Another issue is that the array does matter on select.
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In the past, with one block argument, it would get both the key and value assigned.
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Nowadays, it looks out.
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So Sam Ruby actually originally did this talk at Scotland on Rails in Edinburgh.
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That's another regional conference across the ocean.
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I put out a PDF, and people looked at it on Ruby Inside.
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Sam Ruby recently came out and did another talk; he's much more focused on string encoding.
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This is a really good point he made: one of the main obstacles for us to decide if 1.9 is cool.
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Especially in production applications, is the fact that we have all these gems.
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It’s not like we're Red Hat Enterprise Linux where we have some kind of idea of maintenance status.
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These gems are just sitting around; they might have 1.8 code that's not compatible.
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If you get 1.9, install some gems, and some of your dependencies aren't working right, that's a real problem.
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As a community, we need to do something about that.
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We need to identify these gems.
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Certain gems, for instance Rails, run fine on 1.9.
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The dependencies run fine on 1.9.
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What 37 Signals is using probably runs fine on 1.9.
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That's great, but there's a lot of other stuff that you may be using.
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Maybe you have some crazy list of gems that nobody outside your industry uses.
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You're going to need to do something about that if you want to continue to use your software with 1.9.
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So there's no easy solutions there.
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Now, new features: let's talk a little bit about the mostly syntax changes.
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Some of the encoding changes I don't want to go too deep into.
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M17N—obviously, there's a lot.
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I try not to put a lot of text on the slide, but here it is.
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The main points here are that strings have encodings nowadays.
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Your source files can actually have an encoding.
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You can read things in encodings.
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That encoding affects a lot of things: regular expressions, various methods on strings.
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You can't just do .each on strings these days.
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You have to iterate over characters in each line and each byte.
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You can examine what the encoding is on the string; you also have different ways of setting what your encoding is.
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You can use command line stuff from Ruby and also magic comments.
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If you have the Emacs style comment because you're using X, you can use those.
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I'm sure there's something for Vim as well.
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If you're using TextMate, whatever else—there are basic versions that don't give hints.
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Obviously, I already talked to you a bit about string sub and how to pull stuff out of a string.
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It supports a lot of different encodings; this was a complete list a few months ago.
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It might be different nowadays; it's just a lot of stuff here.
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UTF-8 is obviously the big one for most people that want to do surface languages.
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Being able to pull stuff out of files and do I/O stuff with different encodings—that is now possible directly.
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You notice in the second example I'm using an open version of the new hash with a symbol.
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It reminds you a little bit of keyword arguments, probably, or maybe a little bit of JSON.
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This is a really, really cool feature.
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It's one of the features that checks off that enterprise box that people pass around.
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This is a good thing; it's something people complain about a lot.
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We don't have support for Unicode, etc., and that’s been a valid concern for years.
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It's been worked on, and we're going to continue to work on it.
00:20:26.160
This is really cool because if you're a text-processing person like I am, having good regular expressions is really important.
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One of my main reasons for switching from Python to Ruby years ago was that Ruby's regular expressions were much more natural.
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But it was missing some really, really cool features from newer regular expression engines.
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Now, Oniguruma has been integrated into Ruby 1.9.
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It provides cool things like named grouping, various look-aheads, and look-behinds.
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It also supports encodings, which is obviously an important feature.
00:21:04.000
There are some differences with enumerables and the enumerators.
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In Ruby 1.8, you have to require enumerators.
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In 1.9, all enumerable methods will return an enumerator.
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You can call next on that enumerator.
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You can stop complaining about not having hash each with index.
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This has been a constant complaint for years.
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Now you have it; you can even add your own crazy things onto an enumerator if you like.
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However, this does change things like each with index, so you have to be aware.
00:21:58.560
Dot instead of underscore. If you use RSpec, you're going to be confused where to use a dot and an underscore.
00:22:04.000
You'll probably figure it out just fine.
00:22:10.720
In enumerables, there are some other cool things you can do.
00:22:16.400
You’re familiar with symbols of Proc from Rails.
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That's now in 1.9. Some like it, others don't—that depends on who you ask.
00:22:28.800
There's also something reduce, which is essentially the same as inject.
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You can pass it either a symbol or a symbol to proc.
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It flattens things down; you can think of this like dot sum.
00:22:47.680
There's lots of methods on enumerable that make sense to take a look at.
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Some of which are here: cool things like take and group.
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Group is now part of Ruby, which is nice.
00:23:05.440
Back in the old days, you only had sort, then got sort by, and now you have min by and max by.
00:23:11.680
You can do count, which I believe is essentially dot size.
00:23:17.760
So there are new features; we got take and drop, a way to quickly grab something out.
00:23:23.040
Hash changes: at least the last time I checked, hashes track their insertion order.
00:23:30.240
You can actually go over a hash in the order things were inserted.
00:23:36.320
This is probably familiar to those using PHP with associative arrays.
00:23:43.680
Now, you can see I'm putting stuff in, taking stuff out, and what you're putting in is staying ordered.
00:23:50.720
Tap is a little thing on an object; if you're familiar with Active Support, this is similar.
00:23:58.000
This is very similar to returning, and some say it's not great for performance.
00:24:04.880
Just be aware it's there, and it's kind of neat.
00:24:10.000
What it's doing is passing itself to that block; you can do stuff with that block.
00:24:15.680
This is kind of cool, especially for things where you're fiddling with an object in a method.
00:24:22.560
Returning that object back means you want the scope to be explicit.
00:24:28.960
This is probably the thing when people think of 1.9; it’s the new proc literal.
00:24:35.040
Forgive me if I use the words proc and lambda interchangeably, as they are interchangeable for me.
00:24:42.320
The main thing here is we actually now have something built into the parser.
00:24:48.640
It's flexible compared to using the goal marker type.
00:24:55.200
You can pass blocks to them; it's great.
00:25:01.520
You can also do things like default arguments, which is nice.
00:25:08.720
Also, you can declare things as local variables, which is experimental.
00:25:16.080
I thought I had another slide, but I guess I don't.
00:25:23.440
So simple changes: we’ve got proc; like I mentioned, there’s less sibling rivalry.
00:25:29.920
You know that Rails created this idea of using symbols for keys in hashes, etc.
00:25:37.440
Stuff coming in from parameters were strings.
00:25:43.920
You check them out; especially when you were indexing, it would all fall over.
00:25:49.760
Now you can actually pretend to be a string in certain ways.
00:25:56.560
I know the idea of symbols being frozen strings was flirted with.
00:26:01.920
That was removed due to performance concerns.
00:26:08.080
But now they pretend to be the same, though you can't use = to check them.
00:26:14.160
That would be a bit too much.
00:26:20.000
But triple equals works, so case statements work.
00:26:26.080
Threads have moved to a native threading model from a user threading model.
00:26:33.440
There are actually three different models if you open up thread.c.
00:26:39.760
You do things like that for some reason, like reading through C code.
00:26:45.680
One is user threads, one is native threads with a giant VM lock, and one with finer grain locks.
00:26:52.000
The one built-in now, I believe, is model 2.
00:26:58.560
I don’t read a lot of C in my leisure time.
00:27:05.760
Also, I’m not a VM guy, so I haven't dug in deep.
00:27:10.640
When 1.9 comes out, hopefully this Christmas, we’ll have all the locks down.
00:27:16.560
This is cool; it's nice to run Ruby, kick off a bunch of threads.
00:27:23.680
Performance should be much better; you can look at Top and see the thread count.
00:27:32.000
This has been another checkbox we needed.
00:27:37.040
Especially for people coming from the Java world, this is something they absolutely needed.
00:27:42.720
It's been something that has kind of hounded us.
00:27:47.680
Fibers are essentially semi-coroutines.
00:27:54.640
You can think of them as lightweight, user-level threads.
00:28:00.320
They're manually scheduled.
00:28:06.000
They're kind of neat, especially for I/O frameworks.
00:28:12.640
But this isn't something I generally do.
00:28:18.280
There are good blog entries to read on fibers.
00:28:25.760
Dave has a really good series of articles on fibers.
00:28:31.680
We're going to go into questions. We have about 15 minutes.
00:28:44.960
So questions?
00:28:50.560
I don’t think I can explain the history behind the tap method.
00:28:56.960
Mats may be willing to talk about that later.
00:29:02.560
The tap method seems to owe a bit of debt to returning.
00:29:07.840
So there seems to be that connection.
00:29:13.440
That reminds me of Smalltalk semicolons for chaining.
00:29:20.960
If you can put that up there, you can chain things onto the same object.
00:29:27.280
I can't say specifically why it's called tap. Maybe tapping into the chain?
00:29:33.040
It also reminded me of jQuery if I can go back but in a less gross manner.
00:29:41.760
I really like jQuery.
00:29:49.040
I can’t tell you the etymology of it, but from a usability perspective it owes a lot to returning.
00:29:55.200
There’s a good subset of people in the Rails community that use returning as a pattern.
00:30:02.480
So, yes?
00:30:09.040
Just give us your personal opinions on the changes that happened to lambda.
00:30:14.960
At first, I really hated it.
00:30:22.880
Partially because I’ve used Ruby long enough, seeing any change can be scary.
00:30:29.760
But I love lambdas; it’s my background.
00:30:36.560
At first, it took me back because it felt like a step away from clarity.
00:30:43.520
But knowing all the new, cool things means that there will be great use cases.
00:30:49.680
I'm hoping the Ruby community self-regulates with all this.
00:30:55.760
We can create a schedule of punishments for horrible lambdas.
00:31:01.960
I have disliked making things as obscure as possible to read.
00:31:07.840
I love elegant code.
00:31:13.920
The utility is also pretty significant.
00:31:20.960
One point I want to stress is that the syntax may feel less clear.
00:31:26.280
So, it’s okay to let it sit for a bit.
00:31:32.000
You can play with it; you might feel more comfortable after a while.
00:31:39.040
Does that kind of answer your question?
00:31:44.640
I think I do have time for two more questions.
00:31:49.440
Okay, so do we have another question?
00:31:57.520
If not, thanks for your time, and thank you Mats for being here.
00:32:03.040
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