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RubyMotion - Ruby for iOS (rubymotion.com)
485 points by acangiano on May 3, 2012 | hide | past | favorite | 240 comments

I love writing Ruby code, but today I'm finally at a point where I also feel happy and productive with Objective-C. What made my eyes bulge is this:


No XCode. Instead of obscure and impenetrable project files, a convention over configuration Rakefile. Clean and Ruby-like workflows and repositories.

While you can certainly configure an Xcode workspace to program in RubyMotion, we do not provide any support for Xcode out-of-the-box. We do not believe that Xcode makes a good environment for Ruby development (or development in general). Ruby also makes it very easy to write great Domain-Specific Languages that can be used as elegant alternatives to graphical user interface or data modeling tools. [1]

Laurent Sansonetti gets it. I've been writing iOS code for three years and have never been able to figure out how to have a frictionless workflow around XCode, everything about it is convoluted. The idea of automating frequent development tasks with Ruby generators and DSLs sounds exciting and promising.

[1] http://www.rubymotion.com/support/#faq

At first glance, I was skeptical of this. I was immediately thinking "jesus, wtf? yet another way people want to avoid Obj-C?". But last night I decided to take the plunge, bought a license and played around with it.

I dabbled in Obj-C over the years and jumped on the iOS dev bandwagon as soon as the first SDK was available. It was a long journey and coming from Ruby, I was very resistant. Once you're used to succinct syntax, it's really hard to use something as wordy as Obj-C (this was the main reason I never went back to Java). But over the years I came to appreciate Obj-C. I loved the speed and I clearly knew mobile was gonna be the next real fun thing to work on.

And that's where I've been the past 4 years, iOS land. I'm pretty comfortable now with Obj-C and the iOS framework and have worked on a number of projects in the app store. I can really say that I've seen all levels of crappy to great code. But last night when I went thru the samples of the Ruby Motion stuff, I was a little flabbergasted. I'm (now) so used to XCode code completing long method names and when I saw the Ruby equivalent and how condensed everything was, it kinda blew my mind again. I found myself thinking "whoa, that's right, there's no interfaces" when looking at the accessors (omg, so much less code vs. using typical ivar properties) and just all these little Rubyisms that I'm not used to seeing with iOS. It totally made me smile. Oh yah and blocks! They're, like, readable again. :)

Anyway, just to play around with the examples (which are pretty decent) was worth the intro price for me (I can expense it anyway). One big thing that does not yet exist is IB support. A few years back I switched to IB 100% (when possible) and so I'd much rather lay out my ui vs. code it all up. I've included a good Ars link below and in it Sansonetti says they're coming out with a DSL for easily laying out the ui. That will be interesting and it could push me over the edge for using this on a real project. Time will tell.

I kinda feel like I felt the first time I saw Rails. I would recommend anyone remotely interested just check out the Github demos.


Which makes me wonder.. is it possible to rig up such an environment for standard Objective C iOS app development? It could be huge.

It's entirely possible to use Make (or whatever you want) to build a project. There's no magic to Xcode. You just need to invoke to correct compiler and linker (Apple's GCC, usually), include the right flags and frameworks for them, and probably invoke some Apple tools for things like code-signing.

For writing iOS apps I tend to use the THEOS makefile framework by DHowett gives you fine grained control over everything :)

Do Makefiles count? Xcode project are largely (not so) shiny wrappers around Makefiles and keeping track of files.

This is from Laurent Sansonetti, the original author and long time maintainer of MacRuby. It doesn't say that anywhere until after you buy it, which they should really change since that made me go from "Uh, did some random guys just take MacRuby's code and hack in some extra stuff to sell it?" to "Holy crap so THIS is what he's been working on!"

Actually they say that this is based on MacRuby:


at the bottom of the page:

RubyMotion is based on MacRuby, a widely-used implementation of Ruby created and maintained by Apple for over 4 years. Starting from a solid and stable code base, the guys who originally created MacRuby now work on RubyMotion. You're in good hands.

Ah, now I see! I suppose I glossed over that. It should be bigger. ;)

I agree, I looked at pretty much every page on the site wondering what the connection was to MacRuby, until I found it in the FAQ.

Some impressive stuff here, check out the getting started video at around 4:30 The 'positioning a label' live from the simulator command line is way cool. http://www.rubymotion.com/getting-started/

A suggestion for Laurent Sansonetti will be to release this similarly with the way Xamarin has released Mono for iOS. Basically you should be able to download and use the library for free in the iPhone/iPad simulator and you will need to buy a license if you want to be able to export the app to the actual device. This licensing model has the advantage that is similar with what Apple does for developing apps for iOS.

This will let you, as a developer, try and learn to use RubyMotion before you actually buy a license.

I'd second this suggestion. I love the idea of using ruby on ios, this looks like a womderful solution, and it looks far more rubyish in syntax than Mobiruby (which isn't there yet anyway), but I would really like to try it out for myself in the simulator and develop a few simple apps before deciding whether I would want to use it professionally. If they could limit it to simulator only for free it would be much easier to tell if it is going to be really useful or more painful than just putting up with obj c. Having a demo might even boost adoption.

A question for the developers - did you consider this option and reject it for some reason?

2nd this, that would be awesome. I am very tempted to give Rubymotion a try, but not sure I am ready at the moment to shell out the cash for it.

I don't see the point of this. Objective-C is not hard to learn, and with ARC, blocks, the new literals for NSArray and NSDictionary, etc, Objective-C has actually become pleasant to write IMO. The example RubyMotion code also doesn't look very nice either.

The problem with Rubyists (being one for the past 6 years I feel qualified to say this) is in general they want to use Ruby for everything. It's not always the best tool for the job.

I've never understood this logic: The existence of this project is not an attack on Objective-C. Objective-C is not hard to learn and awesome, I agree. But what does that have to do with providing an alternative? There can exist multiple good solutions to one problem. You said it yourself: Ruby is not always the best tool for the job, perhaps Objective-C is also not always the best tool for the job. Perhaps the use of UIKit through Ruby will provide interesting insights that will later be used to make Objective-C better: all the Objective-C 2.0 additions (including the ones you mention) were certainly a response to modern languages that made a lot of things easier for programmers.

As an Objective-C programmer myself, I was initially really turned off by this attitude from the JavaScript community: (Why do we need we need a LISP implementation in JS? It's already a functional language! Why do we need Objective-J? JS already kind of has classes!). Hilariously enough, the only language that was "accepted" by the JS community was the one that specifically promised that it wouldn't add any new features: CoffeeScript. I missed the Objective-C community precisely because I had always found it quite unreligious and practical: to each his own when it comes to development -- I hope that with its latest success it hasn't become more dogmatic and insular.

I can't speak for the parent, but my take on it is that Ruby is considerably slower than Objective-C and one of the slower scripting languages in common use, IIRC. I wouldn't go out on a limb and suggest that it's unsuitable for iOS development without having a chance to see it myself, but it's something to keep in mind.

As I'm sure you've seen, even Objective-C is too slow for many things when developing for iOS - for instance, if you want to get halfway decent UITableView performance it's best to write a custom UIView where instead of laying out nested subviews, you drop into C and do all your layout in drawRect using only CoreGraphics API calls.

If you're attempting to do anything more complicated than hooking together pre-fab components, your performance is probably going to suck if your views are written in Ruby. And it's the silky smooth graphics people have come to expect that give iOS the reputation it's earned for slick UI.

It doesn't mean you shouldn't necessarily use a framework like this, but you don't get all that convenience for free. I've often felt that the reason Objective-C remains in use (aside from the fact that it's kept alive by Apple) is that it sits in a really practical middle ground between the bare metal performance of C and the convenience (and tradeoffs) of "nicer" languages. As I said above, though, this is just my default reaction, and I'd love to see this stuff in action if it's truly usable for a reasonable subset of use cases.

I can only assume you didn't read up on the technology at all. RubyMotion does not use a Ruby VM, instead it's a static compilation to machine code. So any previous Ruby performance benchmarks are invalid in this instance.

Also, Objective-C is not the slow bit in the example you described. There is a lot of logic overhead in laying out views in Cocoa. While it's true Objective-C (the language) may have some overhead, it's not much. And it's certainly not anything compared to laying out a complex view tree.

It's true, I didn't read up on the tech at all. That was just my initial reaction. If it's fast, great! I'd love to see some performance benchmarks.

As for Objective-C, whether the language in and of itself is the source of the slowness I was talking about is somewhat beside the point, IMHO. I'm aware that laying out views in Cocoa involves a lot of overhead, and that it's as much to do with the complexity of what's going on under the hood as anything. The fact of the matter remains though that you take a performance hit when laying out non-trivial views that need to be updated as fast as possible (e.g. when a table view scrolls by even one pixel and all the views have to be redrawn). You could probably convince me that Objective-C isn't the reason this is the case, but in any event, when you find the need to drop down into direct drawing API calls in order to get the performance you need, the "not much" overhead you're talking about can become much more noticeable. In a tight loop, a factor of 2 can make a huge difference, even though "2x slower than C" would be an enviable benchmark for many languages.

Again, I'm certainly not denigrating Ruby or other languages, but to me, that aspect of iOS development is a reminder that one needs to choose tools carefully for the job at hand. Hence my hesitation at the announcement of alternative toolkits for iOS apps, the vast majority of which I have yet to see any stellar examples of. Here's hoping this will break the mold.

The fact of the matter remains though that you take a performance hit when laying out non-trivial views that need to be updated as fast as possible (e.g. when a table view scrolls by even one pixel and all the views have to be redrawn).

Not true, on a bunch of different levels.

A. Go do a benchmark with a nib loaded with UINib, and then with your "non-trivial view". The difference is negligible. You won't get more than 1-2 fps more by keeping it in code. And honestly? If you're that desperate for 1-2 fps, you're not likely bottlenecked at drawing code.

B. If you scroll by one pixel, at most, you'll have one new cell to redraw: the one that appeared on screen at the end. You don't redraw everything all the time.

C. I find that custom code is usually slower than loading some images and placing them on screen. CoreGraphics functions, for example, don't use the GPU. Set the wrong property on your layer (try touching CALayer's shadow properties on a large scrollview)? You lose ~20FPS. GPU is too busy calculating stuff to actually put stuff on screen, so CA drops frame.

Hey, thanks for the comments. I like talking about this stuff.

A. I wasn't talking about loading a nib vs programmatically wiring up a view. Many people never touch interface builder and write all their views from scratch, but in that case you still have the choice between compositing your view using subviews and overriding drawRect with drawing calls. Have you ever has the pleasure setting up a tableview controller on an older (first or second generation) iOS device? The difference in responsiveness there can be quite striking. This may be a topic rendered somewhat moot with newer hardware.

B. That's not my understanding, but if you have a source on that I'd appreciate a link. I was under the impression that while the cell will only be requested once it comes into view, scrolling the table still requires the visible to cells to be re-layed out, which is where the relative inefficiency of subview rendering starts to hurt you. I certainly could be wrong about that though.

C. If I recall, CoreGraphics is implemented on top of OpenGL. You still don't want to do complex graphics in your cell's drawRect in this sort of situation (I'm just imagining an image and a few labels, nothing fancy). Drawing a static image, pre-generated or cached, is a nice solution in some cases.

Many people never touch interface builder and write all their views from scratch, but in that case you still have the choice between compositing your view using subviews and overriding drawRect with drawing calls.

Many people overestimate how expensive a view is to lay out, and jump straight into code (I'm as guilty of this as anyone else), without actually stopping to see how nibs perform, due to misunderstanding some part of the pipeline.

Have you ever has the pleasure setting up a tableview controller on an older (first or second generation) iOS device? The difference in responsiveness there can be quite striking. This may be a topic rendered somewhat moot with newer hardware.

Yup. Fun times. Glad we're not there anymore. And given AT&T gives away 3GS's for free, I'd have to agree that the topic's moot and go on to say that it isn't worth the time or effort to support a device that no one has anymore ;)

..but if you have a source on that I'd appreciate a link

Add a log to -layoutSubviews of your cell subclass, and look at how often it gets printed out when you scroll.

If I recall, CoreGraphics is implemented on top of OpenGL. You still don't want to do complex graphics in your cell's drawRect in this sort of situation (I'm just imagining an image and a few labels, nothing fancy). Drawing a static image, pre-generated or cached, is a nice solution in some cases.

Go far enough back, and everything UI-related is OpenGL. CoreGraphics, however, is not built directly on top of OpenGL. It's part of Quartz, (specifically, QuartzGL). QGL on Mac can use either CPU-backed or GPU-backed drawing. On Mac, QGL defaults to CPU-backed drawing, but an app can use the GPU backing instead, by setting QuartzGLEnable to true in Info.plist. This option isn't available on iOS. You're stuck with CPU, only, for CG.

I am personally concerned that the Rubyists will flood the iOS development space, bringing their culture and introducing a dogmatic and insular environment.

We already have -- and without great fanfare -- Lua, JavaScript, C# (MonoTouch), et al. This seems somehow different.

How ridiculous. You do realize that every programming community has "dogmatic and insular" people, right? There are Cocoa people I've talked with who were, seriously, the rudest human beings I've ever had the displeasure of talking to.

Douchebags are everywhere and it's sort of silly to paint an entire community with a broad brush. We're doing lots of good things, too, despite our own share of jerks.

Rest assured that your attitude is far more insufferable and real than the "culture invasion" you're concerned about.

Goodness - what a hateful, stereotyping, and narrow-minded comment. I'm enjoy ruby and spend a lot of time writing it, but would never pass judgement like this on anyone who uses another language. I've never interacted with anyone writing in any language that has an attitude like this - let's hope that you are an edge case...

Honestly, I'm part of the mostly-silent majority of polyglot programmers that choose the best language for the job and have grown increasingly weary of Rubyists wheel invention and focus on rock star programming and rock star rants. It's the only community that I find socially insufferable, and while an unpopular opinion here, I don't relish the notion of Rubyist culture.

Culture aside, simply technologically, Ruby has nothing significant to offer as compared to the many existing languages and technology stacks, especially those pushing forward language and runtime research. The only argument for Ruby here seems to be opening the market to developers unwilling to move beyond it.

"polyglot programmers that choose the best language for the job"

You just described the majority of Ruby coders I've ever worked with. (mentally scrolls work history roster of Ruby devs...)

Yeah, in fact you've just described all of them.

I'm sorry your sampling of Ruby coders has been so poor, and I'm sure you could present examples to defend your prejudice. I know the stereotype you're talking about. I haven't worked with one of them, but I know they're out there.

Nevertheless, it seems to me you've become the thing you claim to despise: insular and closed off to experiences that would contradict your dogmas.

If that describes said ruby programmers, then why are they using Ruby?

> Nevertheless, it seems to me you've become the thing you claim to despise: insular and closed off to experiences that would contradict your dogmas.

That would be the opposite of "polyglot". I can find value in Clojure's concurrency design, Python's scientific community, Scala's marriage of OO and functional, F#'s modernization of ML environments, C#'s language design, ObjC's UIKit/AppKit libraries, C's propensity for close-to-the-metal optimization without dropping to assembly, Haskell's lazy evaluation and functional purity, OCaml's mixture of pure functional with mutable state, Erlang's micro-thread actors, Java's virtual machine, Smalltalk's REPL-on-steroids, lua's JIT.

However, almost nothing from Ruby. The technology there is almost totally uninteresting -- it's just yet another imperative scripting language with a poorly designed runtime -- and the community, unlike Python's, doesn't make up for it. In fact, that Ruby community is one of the primary things that seems to give technologists a bad name outside the technology industry. When I hear tales of sexist conference behavior, inappropriate language in presentations, and outright bad wheel-reinventing technology, the tales are almost always tied to either Ruby, youthful startups, or both.

So -- no, I don't look forward to them joining the rest of us in the iOS space.

You're describing a sub-group of young Valley-centric developers (and the occasional outspoken charismatic CEO), drawn to Rails because of its prominence in the start-up environment. It's simple numbers: since Rails is arguably the most popular for ambitious SV companies, then sure, it's going to reflect that culture to some extent. But the community runs deeper than that, and the "Matz Is Nice So We Are Nice" world still exists and thrives. That's the majority of the Ruby and Rails world I've encountered.

Again, I'm sorry your poor sampling seems to have traumatized you into an an irrational, confirmation-bias myopia, but my experience has been very different.

You like C#'s language design? Me too. I especially like its adoption of Ruby-ish idioms like lambdas and the LINQ collections DSL, and the C#-on-Rails framework goodness of ASP MVC.

"it's just yet another imperative scripting language with a poorly designed runtime"

Sweet Lord what an ignorant statement.

Here's the thing that Ruby does astonishingly well that none of those others you mentioned can do: metaprogramming. None of the languages can touch Ruby for its ability to consolidate expressive, DSL-like idioms that eliminate code duplication (and therefore bugs), increase communication and application logic clarity. This is where Ruby really eclipses everybody else, in its ability to create frameworks, DSLs and micro-solutions that drive interesting and expressive conventions that drastically reduces the time it takes to code and deliver a feature out the door.

This is why frameworks like Rails and Sinatra have been so successful with polyglot programmers like the ones I work with, and why new frameworks like Merb and Padrino keep popping up and offer new idioms and expressive possibilities. It's just a creative, open language to work with, that allows a creativity and level of surprising possibilities that have real business consequences. At the application level, where code conciseness and time-to-delivery are at a premium, Ruby simply shines.

I strongly disagree with your statement that Ruby excels and metaprogramming and DSLs. Other languages (Scala, C#, F#, etc) with coherent type systems have demonstrated an ability to define equivalently useful DSLs with the added property of validating correctness of a declarative language at compile time.

You mention LINQ as somehow deriving from Ruby -- it doesn't, it derives from set theory, relational algebra, and some very careful consideration of how to model those in a typesafe environment. You fail to mention that LINQ is type-safe, which is an enormous advantage to its use compared to traditional approaches of modeling set theory / relational data problems, and has value for things well beyond databases or querying simple data structures, eg: http://msdn.microsoft.com/en-us/data/gg577609

You claim lambdas as Ruby-ish idioms, and yet totally ignore where "lambda" derives from: lambda calculus. This is not a Ruby-ism, and Ruby discards much of what is of value in lambda calculus: http://en.wikipedia.org/wiki/Lambda_calculus#Lambda_calculus...

Ruby is a "me too" on those fronts, and not a particularly novel one.

Since I have gone to Ruby and adopted the Religion of Testing First (ok, sometimes Testing In The Middle), I have never missed any sort of type checking whatsoever.

I'm afraid this might come down to a philosophical difference for you.

"Ruby is a "me too" on those fronts, and not a particularly novel one."

Of course. No one, especially not Matz, ever claimed Ruby was novel. Why should I care whether a language feature is new when I have features to ship? What you seem to be dogmatically, blindly ignoring is that Ruby's peculiar amalgamation of existing techniques, borrowed from (standing on the shoulders of) Smalltalk, Perl, Python, certain aspects of Lisp and others, created an expressiveness with those idioms that invited widespread adoption that Smalltalk and Lisp in all their glory only ever dreamed of. Innovation was the least of Ruby's concerns, and it's irrelevant to the conversation at hand.

Type-safety seems to be a big thing for you. This may seem to be an enormous advantage to you, and I wish you well. I personally think type safety is the most overrated language feature in CS history. In my crankier moments I'd say it's essentially a compile-time unit test and refactoring/code-browsing crutch for IDE-jockeys that don't test their code. In my less-cranky moments...I'll probably say the same thing. And that's after a decade and an half in Java and C#, not quite a decade in Ruby. To me, type safety imposes far more overhead than it's worth -- generics, abstract classes, interfaces, all irrelevant and basically built-in and implicit in dynamic environments like Ruby. But that's another digression. Suffice it to say, in my entire software career I've kept track of the sum total of bugs I've fixed related to passing the wrong type to a method, or receiving a wrong type from a method, and that number, to date, is (whirring, calculating sounds): 0. Total number of times I wished I had a refactoring shortcut for "extract interface", "rename method", "introduce parameter object" in a Ruby environment: 0.

I've not written a line of Scala or F#, so I can't speak to those, but the notion that C# could construct a DSL a fraction as concise and expressive as Ruby could is absurd. I like C# quite a bit, but let's not be ridiculous.

And I never claimed that LINQ or C# lambdas were derived from Ruby, just that they were Ruby-ish. Clearly someone in Redmond is watching Ruby and Rails. ASP MVC directly borrows Rails idioms, and many aspects of LINQ seem to have at least had Ruby in view, like 'Select', etc., even down to using hashrockets, although in a different manner. I certainly wouldn't be the first to point these parallels out:





> Suffice it to say, in my entire software career I've kept track of the sum total of bugs I've fixed related to passing the wrong type to a method, or receiving a wrong type from a method, and that number, to date, is (whirring, calculating sounds): 0

This is the classic response. It's also ridiculous. It's not just a matter of "passing the wrong type", it's a matter of using the type system to express higher-level constraints that make it impossible to introduce bugs in a complex system -- bugs more fancy than "I passed a string when I should have passed an int".

Of course, passing a string when you should have passed an int happens with regularity, too, and claims otherwise are a lie, especially if you don't spend a ridiculous amount of time pretending to be a compiler by writing extensive unit tests that would be totally unnecessary if you had one.

> And I never claimed that LINQ or C# lambdas were derived from Ruby, just that they were Ruby-ish. Clearly someone in Redmond is watching Ruby and Rails.

What? I ... no. I point out a 1965 paper on lambdas and you claim MS R&D is watching Ruby? You're comparing LINQ -- which implements a coherent model of relational algebra and set theory -- to Rails?

Ruby didn't pioneer these things, didn't add anything novel to them, implemented inconsistent models of them, and can't take any credit for them.

"This is the classic response."

It's classic because it's true.

"bugs more fancy..."

Fancy? Fancy?? (thumbs through Knuth and SICP looking for "fancy" bugs...looks for "fancy" anti-pattern...)

Nope, not there. Consistent with my own experience, rather than anecdotal FUD (Fanciness Uncertainty and Doubt), after years and years and thousands and thousands of lines of code in type-safe and dynamic environments, I've yet to encounter a significant issue that would have been caught by a type-safe system.

"...especially if you don't spend a ridiculous amount of time pretending to be a compiler by writing extensive unit tests that would be totally unnecessary if you had one."

Complete. Nonsense. I write the same unit tests in RSpec and TestUnit that I write in NUnit and JUnit, and far, far, FAR, fewer lines of code for the same coverage in Ruby. I do NOT write extra unit tests because -- holy crap! I don't have type-safety!

No, type coverage is a side-effect of a well-written unit test. No extra effort whatsoever is needed.

"I point out a 1965 paper on lambdas and you claim MS R&D is watching Ruby?"

This is starting to sound like a debate between a CS student who just got out of a Set Theory final and just figured out who CAR Hoare is, and someone who is just trying to ship features and make sure his company makes money. Yes, I have a decent handle on lambda calculus (thanks for the Wikipedia link) and I know the differences between Ruby's collections DSL and LINQ, having used both pretty extensively.

It doesn't matter. The notion that MS is not paying attention to the most influential application framework of the last 10 years is a ridiculous idea. The fact that Ruby didn't pioneer lambda calculus is...just as obvious as the fact that C# didn't pioneer VMs, GC, generics, etc., and can't take credit for those either, and just as much of a non-sequitur.

Since you're arguing by authority, I've been doing this for 15 years.

"The rest of us" like you're some shining beacon of acceptance and awesomeness as a human being. Your statements directly contradict your message.

You might want to learn the difference between Ruby and Rails. Just an idea.

"have grown increasingly weary of [..] rock star rants"

That's funny, because to me it seems you've taken a few of them at their word about what "the Ruby community" is like (or even the existence of a singular one in the first place).

Following up to note that:

- Despite the opinion clearly being unpopular here, I stand by it: the ruby community is toxic-at-best, and totally technogically uninteresting.

Individual Ruby developers may be very nice people, but that doesn't make the technology any more notable or novel, and doesn't change the general tenor of the Ruby community, which seems to be driven by larger than life personalities and a general lack of solid applied computer science.

Though you seem completely uninterested in anything but repeating your toxic, dogmatic, and insular refrain, I may as well add my voice to the chorus of those who see a different community than the one you do.

But I also want to respond to the somewhat more interesting portions of your argument - is ruby "technically interesting", "notable", "novel", and/or lacking in "solid applied computer science", and to what extent do those things matter? I think it is technically interesting because you can do much with little, notable because it combines the elegant OO of Smalltalk and the weak functional programming of Lisp with an intuitive syntax reminiscent of though dissimilar to Python, not at all novel because it prefers to embrace good ideas from its predecessors, and quite thankfully lacking in leakage of hard computer science into mundane programs. It is wrong for many jobs, but right for many others, and for that it is interesting. It is one of a multitude of languages for which the same can be said.

How does it combine the OO of smalltalk and the functional programming of lisp? What was smalltalk lacking that ruby added?


No he means specifically with respect to Lispiness, what does Ruby have that Smalltalk doesn't. I thought of a few different answers, and then I found them all in Smalltalk, so I think GP is right, on both the OO and FP front, Ruby is pretty much just Smalltalk.

1) Extremely good developer community/support (gems, the #ruby channel on irc.freenode.net, blogs, books, etc.) Just a shit-ton of smart people.

2) Pure command-line interface that works with text files, that makes it work easily with any toolchain. Seems that GNU Smalltalk is the first version which only recently did not require an IDE.

3) All the basic and most useful objects are literals. Enumerators are stupid-easy to use.

4) Much lower learning curve than Smalltalk.

5) Adopts some useful Perlisms into the language mix.

6) A large focus on unit testing, and TDD. And they are very easy to use.

I agree with all of that, and that each of those matter, but those things don't make it Lispier than Smalltalk is...

I thought this rhetorical style sounded familiar. http://news.ycombinator.com/item?id=3844851

I don't think many here are arguing that Ruby is particularly interesting technology-wise. Amongst languages, well, it isn't particularly. But the baseless FUD about the "culture" or the "community" is unnecessary.

A simple Google search would show that issues with unprofessional, sexist, and outright ridiculous behavior in the Ruby community is hardly baseless.

Its driven from the top, largely because most mature programmers that would provide a counter to community immaturity have no reason or need to use Ruby.

Sure, things like that have occurred. They occur in many fields. The Linux kernel mailing lists could make your eyes water at times :-)

Things like "the [whatever] community is toxic-at-best" or "I don't relish the notion of [whatever] culture" are opinions that in Ruby's case are based on the behavior of a minority. It's like if people say all C developers are "fat bearded men." Quite a few are, but it's an unhelpful generalization.

If the Ruby community had a general atmosphere or a policy of encouraging sexist or unprofessional behavior, I'd let these remarks slide. But it doesn't. The articles and rants that make it to HN are usually the controversial parts because that's more likely to get votes on social voting sites like HN, alas.

> Sure, things like that have occurred. They occur in many fields. The Linux kernel mailing lists could make your eyes water at times :-)

And unsurprisingly, Linux is a terrible overall example of quality kernel development and design.

> If the Ruby community had a general atmosphere or a policy of encouraging sexist or unprofessional behavior, I'd let these remarks slide. But it doesn't.

Except that the only times I've ever had to deal with (or hear of, third-hand) a general atmosphere of sexist, unprofessional behavior in technology has been in relation to the startup community in general, and the Ruby community in particular.

> general lack of solid applied computer science

Programming is becoming a huge part of everyone's lives. Languages that ease the learning of CS and lower the barriers to entry are very welcome. And some of them also happen to be great business tools.

Many Mac devs who attended WWDC before the iPhone shipped say the same thing now about iOS developers…

> Rubyists in general want to use Ruby for everything.

Well… why not?

This is a relatively objective statement; the problem with ruby tends to be the crappy interpreter we're forced to suffer through - not the language itself. The Ruby language, in my biased opinion, as far as OO-functional languages go is pure awesome.

My initial reaction was: "A Ruby to Obj-C ABI compiler? Fuck no, what is wrong with you."

Upon learning it was the MacRuby dude: "Holy shit fuck yes".

I really don't want to ditch my entire development workflow to pick up Xcode, and Objective C, and miss out on all of the development libraries and vibrant community that I already have access to.

The problem with company led development environments is that they're tailored to the vendor's, and not the community's, needs. Development is rigid and low on innovation.

If this framework is half as good as it seems to be, within a month we'll see a dozen libraries that abstract all sorts of pain away from iOS development. Abstracting the pain away is something the Ruby community tends to do well.

I've gone from being totally uninterested in iOS development to being excited in what I can do inside UIWebviews. Naive, maybe, but it's probably significantly lowered the amount of investment I have to make into creating an iOS app.

I like ruby but please, do not call it a functional language. Its not even remotely close.

Why not? Sure, neither ruby nor python emphasise immutability, and recursion isn't optimised, but both lend themselves to a functional style if you're so inclined. See http://stackoverflow.com/questions/159797/is-ruby-a-function...

I think 55pts makes an important distinction: just because it's possible to write programs in a functional style doesn't mean it's a functional language. The answer with the most votes in your SO link sums it up: Ruby is an imperative, OO language, and you can be generous and add that it has first-class functions and lexical closures. But JavaScript, Python, Perl, PHP, and C# fall in this category, and maybe Java 8 will too. If they are all "functional languages" then the phrase is meaningless.

Well said. Functional features do not a functional language make.

Actually MacRuby does do tail call optimisation (and so does MRI 1.9 if you turn it on).

> Upon learning it was the MacRuby dude: "Holy shit fuck yes".

Couldn't have said it better myself.

I already know both languages — in fact, I've known Objective-C for 10 years and Ruby for only six — and I still see some reasons why this is interesting.

Anecdote: When ARC was first released, I decided to turn it on for a small project. The very first method I wrote blew up with a memory error. The reason? I used the NSFontMatrixAttribute of NSFontDescriptor. For some reason, ARC doesn't handle it correctly. I've never had such a thing happen in Ruby.

There is still a long way to go from where Objective-C is. It's moving in the right direction, but there's still a long road ahead of it. Ruby is closer to being there, though the lack of tool support (particularly autocomplete) makes it a much less compelling proposition than it would otherwise be.

Also, Ruby can be considerably easier than Objective-C to read because there is a lot less line noise. Objective-C's method names read very smoothly out loud, but they can also be visually overwhelming at times and make code sort of melt together into a wall of text. It's maybe a little bit easier to read Objective-C quickly when you're being very deliberate about it, but it's much easier to skim Ruby in my experience.

I probably won't be using this, and I think your criticism of Rubyists is kind of valid, but I think — for this particular project — you're dismissing it too readily.

> Objective-C has actually become pleasant to write IMO.

Yeah, well, you know, that's just, like, your opinion, man.

Haven't you heard? New shit has come to light man.

In much the same way as JavaScript developers want to do everything in JavaScript, including write mobile apps (PhoneGap/Titanium) and server-side apps (Node.js).

Learning is hard, and doubly so when you're in your comfort zone. You can deride that and make it about a person's "toughness" as a programmer, or you can think about exactly how much time it takes to learn a language and its idioms, highlights, lowlights, problems, and features.

A person who's really good at C# or Java is not going to be really good at Obj-C without losing a significant amount of time. That's why these kinds of projects appear. There's only so much time in the day to learn a new language well. :)

Forgive my ignorance of iOS, but do the current Objective-C based tools deliver "An interactive shell [...] for introspection, live coding and debugging" ? If RubyMotion can actually deliver a real first-class REPL that works, that would be a pretty huge deal. Lack of a REPL is the biggest reason why I dislike mobile (Android) development.

No, it doesn't, and it is the thing that I miss the most going from Ruby to Obj-C. All of the other benefits of ruby over obj-c are great, but it's the interactive shell that is the highlight of RubyMotion to me.

Yes, it's called GDB or LLDB, depending on your compiler. Not live coding though, but I don't know if that's a big deal.

Yes, it's a big deal. Being able to live code completely changes (and dare I say, improves) one's ability to construct rather complicated structures that work because the small building blocks are live-tested. It's fantastic.

And now I'm left wondering how Apple ships anything without a REPL.

It's not a big deal*

* former smalltalker

What are you looking for with an Android REPL? Asking because this is something I might be interested in building. Feel free to take the conversation to email (@gmail) or twitter (@jbrechtel) if you'd rather limit the off-topic discussion.

It would have to be very close to as powerful as deploying code in an APK, in other words few limitations on what kind of code can be run via the REPL. There are two big limitations with Android here, as far as I understand it: there's a fair amount that you're not allowed to do dynamically (like create new Activities), and Dalvik has limitations with dynamic class generation. To be honest I haven't experimented with it much, but I was disappointed that the Clojure and Ruby REPLs didn't quite deliver what I was hoping they would (no fault of the project authors)

In reference to your first paragraph, that's all your opinion. You are completely entitled to it and I respect it. My opinion is that this looks awesome and I really want to try it out. Especially since I know Ruby (and C) but I don't know any Obj-C.

As for your second paragraph, you can say that about any '-ists'. I've met java, python and .Net people who all love their respective languages and just want to code in that. To me, Rubyists aren't better or worse in that respect.

Especially since I know Ruby (and C) but I don't know any Obj-C.

Interestingly, from my point of view, Obj-C made perfect sense to me when I realized that it was basically Ruby with C syntax. Given the heritage of Ruby and Obj-C, they come out as very similar languages, so I found it a breeze to pick up the other.

The hard part was learning the Cocoa (Touch) frameworks, but I'm not sure a Ruby API would have made that any easier. It's simply a massive amount of information to take in all at once.

I think you'll find the difference between working with Cocoa APIs in Obj-C vs Ruby is that it's much easier in Ruby to turn what you've learned into a simple, boiled-down, easier to digest set of helper methods/objects/modules.

For example, in using the RubyMotion beta, after I understood the UIView animation flow, I created a helper method using "yield" to do the actual animation. If I were working in Obj-C, it would've been a lot more work to do the equivalent (and I probably would've just copy-pasted existing code around instead).

Isn't that really the difference between something like:

    def animate

    animate do
      # Do something

    void animate(void (^block)(void))
        [UIView beginAnimation];
        [UIView commitAnimation];

    animate(^ {
        // Do something
Which to my eye are pretty much exactly the same. In fact, UIView already provides a similar method built into the API.

Anyway, I don't want to diminish what you've accomplished. It's an awesome achievement regardless of the language you choose.

In RubyMotion, you can do something like:

    def animate(*args)

    animate(myButton, &buttonAnimateBlockFromSomewhereElse)
    animate(myView, myOtherView, &genericAnimateBlockFromSomewhereElseWithTwoArgs)
    animate do
      # Do something locally ignoring args
And, yes, you can do the same thing with Obj-C and some creative casts...but it's nicer in RubyMotion! (ymmv)

You do it this way:

    [UIView animateWithDuration:1.0f
Not so hard.

But what if I want to have my animations in one object, and my elements to animate in another? Yes, you can have an Obj-C method return a block, but you're going to have to do some nasty casting if you want to be able to call those blocks with an arbitrary number of arguments. (That, or box everything up in an NSArray, which kinda sucks.)

I think I'll try and write up a demo app to explain what I mean...

Yes please do because you are making absolutely no sense whatsoever.

I think you are over thinking things.

He wants to be able to pass any Proc to his method, and any arguments supplied to the method are yielded onto target. A rough Objective-C equivalent would be something like this:

    void animate(void (^block)(va_list), ...)
        va_list args;
        va_start(args, block);

    void (^first)(va_list) = ^(va_list args) {
        NSLog(@"%@", va_arg(args, id));

    void (^second)(va_list) = ^(va_list args) {
        NSLog(@"%@", va_arg(args, id));
        NSLog(@"%@", va_arg(args, id));

    animate(first, @"Hello World");
    animate(second, @"Hello", [[NSNumber alloc] initWithInt:10]);
I would like to see the real-world code too. The frameworks in question revolve around Obj-C-isms, so to see something that completely deviates from those patterns will be interesting.

One of the weirdest, but oft repeated, "criticisms" I hear of Ruby is how much "weird punctuation" it uses. A groundless claim compared to most other languages, though, as this snippet illustrates.

> UIView already provides a similar method built into the API.

Yeah, it's actually much, much simpler to do it in Objective-C in this case.

    [UIView animateWithDuration:0.5f animations:^{
        // Do something


UIView.animateWithDuration(0.5, animations:lambda { //do something })

in RubyMotion. Basically the same.

totally agree with you. just for your statement "I really want to try it out. Especially since I know Ruby (and C) but I don't know any Obj-C.": Would be interesting to really know what is the steeper/longer part of the learning curve: learning ObjC or learning the frameworks. To me, ObjC is a lean language (with an awful bracket syntax just like lisp) but learning the ins and outs of the frameworks is what took me the most time.

Yep - In times when ARC was not invented, memory management took some time to get used to (what with object ownership and such), but you can strike this from the list now. Another thing is that one has to get used to the ObjC way of doing stuff. E.g., Devs who are used to Java will make subclasses instead of categories, add comments instead of expressive method names, and make nil checks where they are not necessary. Or ask where all those open-source projects' unit tests have gone :)

Objective-C's heritage as a strict superset of C means that it's great for doing high-level stuff while still keeping your hands in the low-level (necessary when performance becomes a main concern).

Objective-C's heritage as a strict superset of C means that, ultimately, it's syntax is limited (why do you think all the new literal forms are prefixed with "@"). Ruby, on the other hand, excelles at constructing DSLs.

I think you'll find that this strength of Ruby will make RubyMotion a compelling solution for a wide range of tasks in iOS development. That said, CocoaPod support is built in, so you really can have the best of both worlds.

I use Ruby since 2004 (but not exclusively).

I've been using Ruby to create pleasant to use APIs around more complicated (native) APIs in both Java and .Net and it has always been a very big win in my situations.

I just bought a RubyMotion license and can see it going very far :)

Speed is what you're missing.

Not to denigrate you or your statement, and yes Objective-C is not that hard to learn, but it comes down to speed.

If I've never programmed in Objective-C and if I'm experienced in Ruby my time from concept to live iPhone app can be FAR quicker by using the tools/language I'm already familiar with (regardless of which tools/language).

Remove the concept of learning a new language, a new IDE, and only require that I learn a new lib to work against and I'm FAR quicker.

Yes, there may be some limitations. But this is iterative development. Build something as solid and quick as possible, and give users the chance to play with it. If it works, and you need more flexibility, it's reasonable to spend the time on learning new tools/languages.

Compared to learning Cocoa (Touch), Objective-C is really nothing — especially since to use MacRuby you have to learn a bunch of kinda-awkward hacks they've stuck on top of Ruby to make it compatible with Objective-C (e.g. the "def foo(bar, baz:quux)" syntax and Pointers). It's a very simple language. Unless you are exceptionally bad at learning syntax, you're really not saving yourself a whole lot of time.

You're missing something here. I understand Objective-C, I can write Objective-C code. But it doesn't come as naturally to me as Ruby does, there are certain nuances that I stil don't understand intuitively. Ruby is the complete opposite, coding it is almost instinctive for me.

RubyMotion doesn't just slap on a Ruby syntax, its objects inherit from both Ruby and Objective-C classes with some mixed in Ruby modules.

The RubyMotion development environment is, in my opinion, an improvement over XCode. And of course, there's the REPL.

The "awkward hack" you mentioned is nothing. I don't particularly like the way he's implemented pointers to pointers, but that's also minor. The benefits, for me, easily outweigh the negatives.

I couldn't agree more, and I'm glad to see you picked up on this.

I feel the same way. I'm far more comfortable, and have far more trigger time on one language over another, and those inherent nuances make me far more productive.

Of course it's easy enough to learn a new language/library, but that's not the point. The point is what do I know now, and what can I be productive in, the quickest.


You've completely missed my point. Feel free to re-read what I wrote.

Just for reference, yes I code in both Objective-C AND Ruby.

There are significant speed gains when using the tools/language you're most familiar with. I've seen this first hand with myself, and in others... It's not about "how easy it is to learn" it's about "how much time it takes."

You're mixing together two entirely different topics.

I was specifically addressing this point (which seemed to be the crux of your comment):

> Remove the concept of learning a new language, a new IDE, and only require that I learn a new lib to work against and I'm FAR quicker.

That's a bit like saying, "Remove the concept of putting on running shoes and warming up and only require that I run a marathon and I'm FAR quicker." The time to tie your shoes is nothing compared to running the marathon. Likewise, the trouble of learning Objective-C (especially with a background in Ruby) is insignificant compared to the time it takes to learn Cocoa.

> That's a bit like saying, "Remove the concept of putting on running shoes and warming up and only require that I run a marathon and I'm FAR quicker."

It's not at all like saying that. Feel free to keep your words out of my mouth :)

> ...is insignificant compared to the time it takes to learn Cocoa.

I see you've changed from using the word "easy" to the word "learn." That's a step in the right direction :)

Though, we are not comparing the time it takes to learn Cocoa vs. Objective-C. That was NOT the crux of my comment. Again, you're missing the point (you seem to be very talented at this).

The comparison is with Ruby ;)

I know you aren't comparing the time it takes to learn Cocoa vs. Objective-C. My point is that if you did make the comparison, you'd realize that if you have the time to learn Cocoa, you have the time to learn Objective-C, because the latter takes basically no time compared to the former. You get a time savings of like 0.05% by learning MacRuby instead of Objective-C.

No hostility :)

You're just on the defensive, so it feels like hostility. It's understandable...

> My point is that if you did make the comparison...

But I didn't.

I never compared the two.

My statement was one of a speed gain by simply using the languages/tools you're most familiar with, instead of learning new languages/tools.

It cuts out a lot of time, it's not a hard concept to understand ;)

> No hostility :)

> You're just on the defensive, so it feels like hostility. It's understandable...

Really, no. I don't know if it's intentional or not, but you come across as very passive-aggressive and condescending. I don't even know what it is I'm supposed to be "on the defensive" about — the fact that learning Objective-C takes much less time than learning Cocoa? I feel pretty secure in that knowledge.

> But I didn't.

> I never compared the two.

Yes, that is my point — your opinion has no sense of scale, because you haven't compared the two. You're talking about saving pennies on the price of a sports car. I just don't think it's a particularly pressing concern. If you're that worried about pennies, you're probably not in a position to buy that car.

But, you know, whatever works for you.

Apparently the disconnect here comes because you think of a language as trivial (as compared to an API), however it's often hard to separate the language (syntax, and its built in methods), and the libraries which make up an API/standard library. In addition to the cost of learning a library/language, there is also a day to day cost in using it - a certain friction which encourages you to take some paths and not others. A language and the available tools constrains the way you think about problems you are solving, and in some cases might dictate the sort of solutions you come up with.

For example, consider using regular expressions in Ruby to check a string -

  puts "The limits of my language define the limits of my world" if string =~ /foobar(\d*\w)/
or in Objective C:

  NSError *error = NULL;
  NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:@"foobar(\\d*\\w)"
  options:NSRegularExpressionCaseInsensitive error:&error];
  NSTextCheckingResult *match = [regex firstMatchInString:string
                                                  range:NSMakeRange(0, [string length])];
  if (match) {
    NSLog(@"The limits of my language define the limits of my world - Wittgenstein")
Until quite recently it wasn't even possible to do this in ObjC without an external library.

I don't understand how this relates to anything I've said. How is this meant to show that the time it would take to learn Objective-C while you're learning Cocoa is prohibitive?

Actually, I think your code examples support my point. You're not contrasting Ruby and Objective-C, you're contrasting Ruby's standard library with the Objective-C library Foundation, which is what you need to learn to get any real use out of MacRuby/RubyMotion. Here's the MacRuby/Cocoa version of that code:

  error = Pointer.new_with_type '@'
  regex = NSRegularExpression.regularExpressionWithPattern("foobar(\\d*\\w)", options: NSRegularExpressionCaseInsensitive error: error)
  match = regex.firstMatchInString(string, options: 0, range: NSMakeRange(0, string.length))
  NSLog "The limits of my language define the limits of my world - Wittgenstein" if match
Do you really feel that Objective-C is the biggest difference between the three examples?

BTW, if it sounds like I'm trying to say RubyMotion is pointless, I'm not. I'm just saying that "I don't want to go to the trouble of learning Objective-C" is a weak reason to use RubyMotion, because you'll have to do 99.95% of the same work anyway.

Are normal ruby regex expressions not available in macruby/Rubymotion? If so, why would you bother to use the above code using cocoa regex when the idiomatic ruby version is so much shorter and simpler?

The example was supposed to illustrate that some things are easier and more concise in ruby, and thus also presumably in something like Rubymotion. The relevance to your posts is that you are ignoring some very good reasons to use ruby in your focus on the cocoa api - not all programming in ios consists of calls to the api so learning it is not the only thing required to make an iPhone app. In some apps api calls might make up half of the code, with the rest being back-end stuff. Evidently Rubymotion does not mean you can avoid learning the api, it just helps you write the rest of your code in a preferred language while painlessly calling the apis to show stuff on the screen. Not having to deal with Xcode would be a bonus too.

I really feel like you believe I'm arguing that you shouldn't use Ruby or RubyMotion. I'm not! Ruby has been my go-to language for half a decade now. Heck, I even follow both the MacRuby mailing list and Twitter list. To reiterate, this is the entirety of my argument:

> "I don't want to go to the trouble of learning Objective-C" is a weak reason to use RubyMotion, because you'll have to do 99.95% of the same work anyway.

The fact that Ruby can express things very concisely has nothing to do with whether or not learning Objective-C adds an appreciable amount to time to the process of learning Cocoa. That's why I was ignoring it. If you simply like Ruby on its own merits, that's a good reason to use it.

> The fact that Ruby can express things very concisely has nothing to do with whether or not learning Objective-C adds an appreciable amount to time to the process of learning Cocoa.

Here's the disconnect. That was never my point.

Please re-read my initial comment. You responded to that comment, hence you're responding to my initial point, which has nothing to do with your argument.

Do you get it?

The problem is your just not able to express your point, clearly, in relation to the context of this topic. Maybe face-to-face, verbally, you'd do a brilliant job of it. But in the written form, well... Not so good.

A little humility on your part would go a long way. Just saying ;)

def foo(bar, baz: "something") is perfectly valid ruby(1.9).

Really? What on earth does it mean? The "baz: something" ought to parse as a hash literal, which isn't legal in a method declaration.

Now I know where I got that from: its the proposed keyword argument syntax for ruby 2.0.


Sorry, I really should get some sleep: i read "foo(a: b)", but wrote what you wrote and complained about it. :)

You are right :).

I agree, language itself is not a problem. It is iOS API that matters (or needs to be fixed, in context of this thread).

Actually, I can say the same regarding Java/Android API correlation.

The point is that compared to Ruby, Objective-C is just aging, bloated, and incomprehensibly loaded with special traps designed to keep you wedded to the platform.

Ruby skills: applicable across a very broad range of computing devices. Objective-C: not so much.

It might not be the best but it's good enough. Most of the heavy lifting GUI code is still in Obj-C, it's just going to be hitting ruby for microseconds.

Sure if you're writing the unreal engine it's not going to be the best idea, but it should do fine for a Facebook/Three20 type app.

a big different is, now the ruby eco-system is in play. the ability to write DSLs to further enhance the development effort.

>problem with Rubyists...want to use Ruby for everything

This is generally true of the Java community as well. There was a solid decade where there was a jSomethingOrOther for everything in development.

Now that typically means it's a jQuery plugin ;)

By all means, rub in further how old I am now :P

Objective-C sucks as a language. It's just awful to look at, isn't really that much more efficient than C++ or even C itself, and realistically the only reason we use it in the first place is because it's the language of iOS.

Sure, it's not hard to learn. But in my spare time, am I really going to work with a language I can't stand to make my iPhone app or am I just going to want to make a web app in Ruby? The latter sounds a lot more fun, but the former is obviously more efficient. The fact that we can now combine both? Holy shit.

For me, the REPL is the key that makes this interesting. I don't really know much ruby, but I would consider picking it up again just for the interactivity you get with a REPL tied to the app running in the simulator.

This is a step in the right direction, a step toward getting immediate and interactive results when you code.

The piece that I find a tiny bit lacking is disconnect between what you futz with in the REPL and what is your source. By that I mean, all the manual tinkering in the REPL isn't saved anywhere, you have to copy and paste.

Emacs rectifies this sort of thing a little with swank and slime. Maybe there will be a mode for RubyMotion.

This is really awesome, but I found some bad news in the FAQ:

> Because RubyMotion implements a dialect of Ruby that is statically compiled, regular Ruby gems will not work in RubyMotion. We provide documentation which describes how to architect gems to work with RubyMotion.

Anyone who has done any serious MacRuby development would already tell you that normal Ruby gems aren't usually the best way to go (slow, don't use Objective-C frameworks).

I can see where this could be a problem if you typically just glue gems together to make products, but if you're used to rolling your own solutions it isn't a big deal.

Sucks, but not a show stopper.

On the upside, CocoaPods support is integrated with RubyMotion. Sure, there is a whole world of useful Ruby gems, but, generally speaking, the libraries you'll find in CocoaPods have been developed specifically for iOS.

I personally don't care, as I will mostly use a mixture of well-tested, iOS specific ruby libraries I will write and share, together with ObjC libraries.

I didn't see any documentation describing the ins and outs of statically compiled Ruby. Anyone know how it differs from normal Ruby?

Part of me is happy. Apple pushed MacRuby before Lion and effectively killed it internally going forward after the ARC announcement. MacRuby relies on the GC capability of Objective-C which is incompatible with their new ARC baby. Just a few days ago I wanted to take a backend framework we wrote and build a command line tool to call some of it's methods in MacRuby (lots of command line parsing and Ruby has good facilities for that) but forgot we converted that framework to ARC. No dice.

This looks promising but at the same time I really wish the backend compiler was open sourced and worked on Mac and not just iOS.

It doesn't sound like they're using ObjC garbage collection, which I do not think would be available in iOS anyway:

"Our memory model, similar to Objective-C ARC in design, does not require any extra memory or processor footprint to allocate and reclaim unused objects"

Since Laurent Sansonetti is the author of MacRuby AND RubyMotion, he already said feature from RM will be backported (and hence open-sourced) to MacRuby

I'll simply point you at Laurent's email to the MacRuby-devel mailing list about a month ago. I think re-reading it in light of today's announcement could be...informative ;-)


I've played around with what seems like ever alternative framework under the sun (Titanium, Rhodes, PhoneGap, MonoTouch, Corona) and have been pretty frustrated with how clunky they usually feel. However with everything its claiming and the decent price point I'm toying with purchasing site unseen...just wish I could try it for a few hours first.

MacRuby is probably a decent place to start. While it won't mirror a true RubyMotion environment, it should be close enough to get a feel for what you're in for.

This looks really cool -- would be nice if there was some way to try it out before buying.

Cool free 50 min video on RubyMotion -


Just a note, not sure if this is intentional, but the audio on the video is in stereo, but with no right channel.

edit: also, please stop the heavy breathing into the mic. Driving me crazy!! :)

I could not watch the video (on headphones) because it is physically painful to do so. That's a HUGE problem.


Be sure not to miss all the sample code: https://github.com/HipByte/RubyMotionSamples

In particular, for those looking for a side-by-side comparison of what it means to use Ruby instead of Obj-C, be sure to check out the GestureTable sample: https://github.com/HipByte/RubyMotionSamples/tree/master/Ges... which was based on the JTGestureBasdeTableView: https://github.com/mystcolor/JTGestureBasedTableViewDemo

"At the end, a RubyMotion app looks pretty much the same as an Objective-C app." ( from bottom of: http://www.rubymotion.com/features/ ).

pretty much the same as an Objective-C app? Anyone have any clue as to why they didn't state apps in the two languages would look identical?

Different compilers will generate different compiled code, even on identical input (ie, clang vs. GCC). So the binary will be different.

I think he's commenting on why they wouldn't LOOK identical, as in UI.

UI is a finicky thing, but assuming this allows you to use all Apple APIs, there is no reason you couldn't get an identical-looking UI using this.

I'm fairly sure that section is talking about compiled code, structure of the app, the archive, etc, considering it says "compiled ahead-of-time, never interpreted, and you access the entire set of iOS public APIs." the previous paragraph.

You're right though, there's no reason the UI wouldn't look identical as well.

nice, but where is the advantage over just using objc? the hard part of coding for iOS isn't objc, it's learning how to use all the API's.

I write code in both Ruby and Objective C pretty regularly, but man oh man is my Ruby code SO MUCH shorter and cleaner in a lot of respects. A lot of the Objective-C API's are just terribly terribly verbose. My favorite one to whine about is NSTask; it shouldn't take me 10 lines of code to spawn a simple external process. :P

For me, I prefer working in Ruby. Some people don't. But I think this will probably spurn me to get more serious about writing more iPhone apps, and it should open the door for a few more people who work on Ruby-based apps to write their own simple iPhone apps rather than paying a consultant to do it for them.

But you're going to be coding to those same Apis in ruby too, just with a lightly different syntax.

No, actually.

I can use Ruby's nice facilities for external processes (e.g., "x = `ls`" to get a directory listing or "system('do_something')") or simple regular expressions (i.e., "'string' =~ /my_regex/" and friends vs. NSRegularExpression's verbose syntax). I'm not forced to use Cocoa's verbose API if it has a nice Ruby wrapper (and if it doesn't have one, I can make one).



Is what 95% of the code in your app is going to look like and I don't really see what it's buying you. You're also throwing away all the type checking you'd get on essentially the same code in Obj-C.

I really like Ruby but I don't intend to use it for iOS apps.

Having been part of the private beta I can tell you that it's a huge time saver. Objective-C is nice be ruby is much more expressive, you can use the same API with much less code, you can skip XCode altogether and use your favorite editor, ...

I can't express properly how awesome it is, really.

In the Ars article, I noticed the author mentions you can't use XCode's layout tools.

In practice, how big a problem is that?

Some people hate interface builder and don't use it at all. I really like it and would have a really hard time getting rid of it. The amount of code you would need to write to make all of your views would be terrible.

I would liken it to not using HTML when you're making a web app and you can only use javascript to generate (by hand) all of the UI.

Except that I feel the control you lost by using IB is smaller compared to the control you lose by using an HTML builder. But then again, it's been forever since I last used an HTML builder.

In both cases, there are border cases that need to be handled in code (or markup).

I quite like Interface Builder, and this sounds like a bit of a deal-breaker for me. I'd rather not have my controllers cluttered with UI-positioning code, etc. It's a much more elegant way to create you UI (most of the time).

I bet they are working on it, though...

I tried a bit, technically it works but currently you have to compile your xib to nib manually using ibtool.

That may have changed tough because I dropped the xib as I didn't really needed it.

How does that work? Layout the view, convert the XIB to NIB, and load it at runtime?

In relation to working with Appcelerator or a similar system that allows you to load in images/views/visuals & position programmatically, I wouldn't say it's a problem, more a shift in practice.

The call syntax is still painful compared to straight Objective-C as it actually uses more characters and is not as clean. I really wish he had come up with something that resembled Objective-C better.

I may have missed something but API calls looks like a regular Ruby call with a hash and since all [] are dropped it's systematically shorter (not even counting the fact that you don't have .h/.m, declaration/implementation, it's not just a matter of API calls).

i.e. [obj method: param second: param2]; vs obj.method(param, second: param2) which is exactly two characters shorter in ruby.

And what would be the point of having something that looks like Objective-C?

I was looking at the example and their are a fair number of commas. If you pass 3 selectors it is longer.

  UIColor.colorWithRed(red/100.0, green:green/100.0, blue:blue/100.0, alpha:1.0)

  [UIColor colorWithRed:red/100.0 green:green/100.0 blue:blue/100.0 alpha:1.0];
>And what would be the point of having something that looks like Objective-C?

Because the name of the function is not colorWithRed(), it is colorWithRed:blue:green:alpha:.

Seeing as we're splitting hairs... :)

In the Ruby version I wouldn't use that selector with any parens. The resulting line would be one character longer than the ObjC version but use the Shift key one less time and would avoid two pinky trips out to the square brackets. (unless I am miscounting)

All other things being equal between the two options, and of course they aren't but let's just keep splitting hairs for a moment, it sounds like a typing win for the Ruby option. Readability is of course in the eye of the beholder.

If you want objective c syntax and behaviour surely you'd just use objective c?

Ruby is really nice for everything else, but the call syntax over to Objective-C is not quite good.

I agree, but many young developers have C phobia and somehow seem not to be able to grasp C based languages.

I like C but have Obj-C-aversion because "high level" languages that still need header files all over the place just ain't right.

There I agree with you.

Header files are so 70's.

Or they've been spoiled by certain language features and it seems unbearable to go backwards.

What language features does Ruby have that Objective-C lacks? It's a bit more succinct, perhaps, but when you're calling out to Cocoa all the time, that succinctness is going to get thrown out the window.

Ruby has "yield" which, while possible to replicate in Obj-C, it's not nearly as nice. Also, Ruby can yield arguments, and the block being yielded to is free to ignore those arguments. That's the sort of flexibility that can make Ruby so much more enjoyable to work with in high-level code.

That's a great example, thanks!

I did some looking, and I found a few[1] examples[2] of coroutines in Objective-C, though none of them seemed fully fleshed-out. Even if they were, none were, as you say, nearly as nice as "yield".

[1]: http://cocoadev.com/wiki/CSCoroutineTest

[2]: https://gist.github.com/1033477

Personally I find great that we have a native Ruby compiler, even if it means a static language with Ruby like syntax in the end.

I hope for the day when we have better and more type safe languages for system programming.

Most attempts so far, Modula-* family, Ada, Oberon and so on, failed to catch on, to my dismay.

Still it does not hurt to know some C.

It depends, if your background is in dynamic languages like Perl, Ruby, Python than using Ruby for iOS makes a lot of sense. On the plus side Ruby is better for programmer productivity.

If you have a good background in C than yes, using Objective-C is not so difficult.

I concur with the other posters who say Objective-C itself is not the barrier, the API is. Such is the design and verbosity of the API (which is great for self-documentation and talking about, less so for typing), it'd be an absolute nightmare to work with without the extensive auto-complete Xcode offers.

This is a very exciting (and very positive) development, but at this moment in time I would still bite the bullet with Objective-C. I came to it with a background in PHP of all things and didn't struggle with picking it up in a few weeks.

I can't wait to see the things people do with it and with Ruby's metaprogramming.

I don't understand all the hate for Objective-C, and at the same time love for Ruby. Objective-C is far easier to read, with named parameters and types everywhere. Ruby is often so minimal that you need to interpret the whole program yourself to understand what's going on...

The most exciting part of this for me is the automation and integration with Apple's tools.

For instance, built-in TestFlight rake task, or build and run on device/simulator. I'd love to borrow some of that for a CI build system (which for me is currently a large shell script that could be improved on).

I'm also very interested by the interactive REPL that can run code inside my application. LLDB is good, but falls short for me occasionally.

Will apps created using this have any problems getting approved with App Store?

No. From the FAQ (http://www.rubymotion.com/support/#faq):

"Applications submitted to the App Store must conform to the Review Guidelines dictated by Apple. RubyMotion implements a dialect of Ruby that conforms to those rules. RubyMotion apps are fully compiled, do not download or interpret code and are using public iOS APIs through the exact same machinery as regular Objective-C apps."

I would rather see confirmation from Apple (doubtful) or developers who have successfully submitted apps to the App Store.


At the bottom of the features page

>RubyMotion is 100% compliant with Apple's App Store policies. Your code is compiled ahead-of-time, never interpreted, and you access the entire set of iOS public APIs. At the end, a RubyMotion app looks pretty much the same as an Objective-C app.

Looks very promising. I love Ruby and I initially hated Objective-C but I have to admit now I find it very powerful. The biggest missing link here seems to be the Storyboard. Its a really nice option in xCode. Have I missed something, how are layouts defined separately from code?

I love this. It looks like exactly what I've been looking for since the iPhone SDK was first announced. I've been a web/RoR developer since high school but could never find the motivation to get used to all of Objective C/XCode's quirks. I've tried everything from PhoneGap to Appcelerator to mimicking native feel in a browser, but it was never enough. This is perfect.

But quite frankly, I can't afford it. I'm a college student living on $25/week for food - I can't justify spending 6 weeks of food on an experiment.

If I could try it out? If I could build my killer app first and know that it works? It wouldn't hurt as much, but $150 is still a lot of money.

But you could justify spending 4 weeks food on an experiment? Because you'll need that $100 to put an app on your device, as well.

Ahh yes, that's not particularly fun either.

If you'd sat down and spent all that time on Obj-C you'd be coding away at it by now.

Sometimes searching for an easy way out is a waste of time.

Fair point.

I am not criticizing. This is a perfectly neutral question:

Isn't the issue with a lot of these "look Ma, no Objective-C" approaches in that there are always little nagging issues here and there?

I mean, Apple is constantly moving Objective-C/Xcode/iOS (notice I didn't say "forward"). Isn't it somewhat dangerous to adopt peripheral approaches for development rather than staying (suffering?) with the Apple-provided tools?

Now, if someone has an alternative IDE that truly allows me to record Xcode to a DVD and perform a ritual burning ceremony of said DVD...that would be something.

What you have to keep in mind is that RubyMotion is not "just another wrapper". It is actually implemented on top of the Obj-C runtime. So that means Apple would have to make breaking changes to the runtime (the thing documented here: https://developer.apple.com/library/mac/#documentation/Cocoa...) in order to break RubyMotion.

I said this in another reply, but I'll reiterate here. It's not the lack of Objective-C that is the big deal here. Afterall you are still interfacing with cocoa, and are stuck with a lot of the verbosity in doing that.

The real key to this is the REPL and interactivity between coding and the running app. Being able to edit bits of functionality and structure in the running app, and immediately see the results is AWESOME!

I don't know Ruby. Therefore, by my own admission, this comes out of complete ignorance.

I am currently working on a project that uses a genetic solver and some fairly complex state machines driven by fairly involved databases. I can't possibly see how something like this could be made to be interactive in terms of the development process. Generally speaking you are writing a lot of code before you get to compile and see the results. And, personally, I don't have any issues with the compilation process.

What do you mean by "interactive"?

Your application is something that doesn't lend itself to the problem that this solves. With UI related things, it is often very helpful to be able to tweak UI elements while the program runs, instead of the tweak, compile, run cyle.

This is huge from a programmer productivity perspective.

Now there is an alternative to Objective-C in iOS development(for Rubyists). This is similar to development of Coffescript. There is nothing wrong with Objective-C, it is just that folks who prefer the elegance and beauty of Ruby have an option. I think this will be great combination - beautiful & elegant language for creating apps on a beautiful platform.

Are there any example apps in the wild that were made using RubyMotion?

There's a few example rubymotion apps at: https://github.com/HipByte/RubyMotionSamples

I find them really easy to follow.

From the screencast it looks like they altered Ruby syntax by adding named parameters to conform with Obj-C's way of specifying prototypes. I guess this is a trade-off for the fact that Obj-C has some unusual syntax that has no real analog in Ruby -- if you've ever tried developing with PyObjC you'll be familiar with how odd it looks.

Problem in search for a solution? Apple is walled garden - provides the best integrated IDE for iphone development that is a pleasure to use. Language is just a small part of the puzzle. For each task, the best suited environment and language. There is no panacea.

How does memory management work with ruby and iOS? I did not find the information on the website.

From the Features:

"It's Ruby, you don't need to think about managing memory. Ever. RubyMotion will by itself release the objects you create when they are no longer needed. Our memory model, similar to Objective-C ARC in design, does not require any extra memory or processor footprint to allocate and reclaim unused objects."

I still wonder how they did that. The classic problem with reference counting is correctly releasing cycles, which ARC handles by allowing "weak" references. How does MacRuby know when to insert a weak reference as opposed to the usual "strong" reference? If that could be automatically detected, why does Obj-C ARC not automatically do it for you?

"Object cycles, when two or more objects refer to each other, are currently not handled by the runtime, but will be in future releases."

So, basically, you're stuck with retain cycles right now. My bet is that they implement a way of marking weak references rather than becoming more intelligent than ARC.

I wonder how big a deal this will be. Relying on GC feels like it goes hand in hand with dynamic languages. I'm used to not having to worry about cycles.

Of course, I guess I'm use to not having to worry too much about memory, either ...

Weak references aren't a panacea. It's not that uncommon to have cycles where all edges are equally strong. Any social graph ...

I use use counts to collect those cycles. ARC doesn't let you use use counts, but you don't have to use ARC everywhere. You do have to access to the underlying use counts ... MacRuby should allow access to that (it's just a standard Cocoa call) as long as it doesn't keep stray retains around that screw up my count balances ...

You can still use counts — you just can't use Foundation's retain count.

And I think CoreData is the answer to problems like a social graph. It does its own specialized memory management. But you're right, it's awkward to have to think about it.

Figuring when to use strong and weak is the only problem I have with ObjC.

Ruby :

"The limits of my language define the limits of my world" if string =~ /foobar(\d\w)/#

Objective-C :

  NSError *error = NULL;
  NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:@"foobar(\\d*\\w)"
  options:NSRegularExpressionCaseInsensitive error:&error];
  NSTextCheckingResult *match = [regex firstMatchInString:string
                                                   range:NSMakeRange(0, [string length])];
  if (match) {
    NSLog(@"The limits of my language define the limits of my world - Wittgenstein")
Enough said?

What's with the price difference between Canada and US orders? It's CAD$152.82 versus US$149.99.

With the Canadian dollar currently worth about 1 cent more than the US, I'm surprised to see that there is a price difference at all.

The nominal exchange rate you see has only a passing resemblance to exchange rates charged by CC processors.

I'll say this again: No programming language is fundamentally bad.

Bad programmers have a tendency to move from language to language, blaming their tools for their lack of skill.

This stuff is exciting.

I wholeheartedly disagree. There are bad programming languages. Brainfuck is a good example. I don't mean that as a joke, but only as proof that programming languages can be objectively bad. As an extension of that I'd say that languages can be bad because of their constituent parts (syntax, semantics, constructs, features or lack of, etc..).

Some languages have constituent parts that I'd say are objectively bad. I'll argue all day that Objective-C's handling of nil is stupid beyond belief. Nil/Null itself is bad enough...

At the very beginning of the presentation he underlines the importance of the static compiler RubyMotion is based on, yet at 7:30 when he compiles a file with a name error in it the compiler doesn't even file a warning. Such non-existent methods and other similar errors should be caught at compile time if we're talking about solid AOT compilation.

I thought Flash got in trouble for targeting iOS with something not originally written in JS or ObjC, is that still true?

I don't remember the last time I was excited about some new technology, but rubymotion is a thing I was looking for since the release of iOS SDK. I was doing ruby for 5 years, and switched to iOS/ObjC half a year ago, and I still can't stand the Objective-C syntax.

missing trial period so i'd rather wait for mobiruby

The difference is that, as far as I can see, mobiruby is a Ruby interpreter/VM embedded in an Obj-C application. This is in contrast to MacRuby which is implemented directly on top of the Obj-C runtime. So, MobiRuby still has to go through the work of converting Ruby objects into Obj-C objects, whereas in MacRuby a Ruby object is an Obj-C object.

For a practical example of what this means, see the most recent sample code that was released for mobiruby: https://gist.github.com/2577620

But mobiruby does not compile to native code, does it?

No interface builder? Depending on what type of apps you make it can be a big issue I think

The problem with interface builder is that it only exposes some properties and others you have to set in your class anyway. Why can't I set the background image of a view in interface builder, for instance?

With RubyMotion you get to roughly lay out your controls, and then you get to use the interactive interpreter for fine-grained adjustments. See around the 5:30 mark in the getting started video for an example.

It's nice, I'm new to using ruby (I've been an iOS dev for a while now), I'd give it ago.

But I assume it uses storyboards in the same way as ObjC, set it in the target and in the Info.plist, and it figures it out... it'd be nice to see it working though.

I second this.

> RubyMotion is built on top of iOS. You have access to the entire set of public iOS APIs and can also use 3rd-party Objective-C libraries or Gems

So this should be compatible with cocos2d right?

cocos2d is writen in Objective-C so in principle it should be compatible with RubyMotion. Not so sure about the ARC integration (last time I've checked cocos2d was only "ARC compatible"). I've seen some work arounds using a cocos2d as a static library (no ARC enabled) linked with a main Objective-C application that uses ARC. It should work ... but I can't give you a final answer.

There is already an example project on Github using Cocos2d in a RubyMotion app. https://github.com/anydiem/cocosmotion

I could see this really taking off.

My worry is that it would take off so well that the ruby gem community could get fragmented into libraries for RubyMotion and libraries for regular ruby projects.

There are already exclusive libraries for MRI/JRuby, so adding a third platform doesn't seem like it would break the world. Tools like Bundler do a great job of keeping things moving smoothly.

Didn't realize bundler kept track of what ruby you were using.

Yeah, check the "platforms" directive.

I'm supposing that they will probably implement it as another platform option like you can do right now for JRuby/Windows/etc. It shouldn't affect much. I haven't looked at the documentation, though, so I can't say for sure.

As mentioned above, CocoaPods will probably be used for this purpose as it is already the de-facto repository for MacRuby.

I am wondering is anybody asked for a debugger/stepper. Will a dev survive without those? Also, are you ready to write all the code behind xibs?

Purchased. Good job, @lrz. Glad to know your departure from Apple and (apparent) distancing from MacRuby were in a good cause.

He did not distance himself from MacRuby, though: http://lists.macosforge.org/pipermail/macruby-devel/2012-Apr...

What annoys the crap out of me isn't objective C, it's XCode.

This looks worth it just to have an XCode-free toolchain.

Should make for some good bridge FU on hypercritical this week...

Sounds awesome - gives me another reason to buy a Mac.

Anyone know if this comes with the ruby stdlib?

It doesn't look like it. You need to use the iOS alternatives (in this case, NSDate).

  (main)>> require 'date'
  => #<RuntimeError: #require is not supported in RubyMotion>
  (main)>> Date
  => #<NameError: uninitialized constant Date>

anybody understood what rubymotion offers over the standard macruby? edit: got it, static compile and no gc

so, we need a mac for this. right?

Yes... "You will need a Mac running OSX 10.6 or higher."

- http://www.rubymotion.com/support/#faq

My thoughts: "Hey! This looks pretty neat. Oh it's $150 on sale, forget this. Oh it's only for macs, glad I never bought this piece of garbage."

That being said, it could be great, I have no idea.

The iOS SDK itself is only for Macs. It seems like a reasonable requirement for something that depends on the SDK to run on the same platform.

Maybe that's because Macs don't generally deal with pieces of garbage. Whether that's tools, or users.

If you really think one platform is so superior to another, you're missing the point entirely.

I think you've clicked on the wrong site. Digg/Myspace is --------------> that way.

There's a reasonably new language called HTML that is a good development platform too. Works on all devices.

"Good" and "Works" being relative terms, of course. YMMV, especially amongst devices in the installed base where web views aren't GPU-backed (e.g, on one common platform, that being the vast majority).


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