Why Rubyist Will Love Swift

Why Rubyist Will Love Swift(littlelines.com)

36 points by mattsears 11 years ago | 40 comments

Argorak 11 years ago |

I'm not buying this. It basically says "there are a few concepts in Ruby that map nicely to Swift". There are quite a lot of concepts that don't map, for example evaluated classes, which enable things like:

    class Foo
      include Virtus.model

      attribute :foo, String
    end

Now, I could go on like this, but that would be moot. I just question the basic premise of saying that just because 5 features match somewhat nicely (even if it involves more braces of different kinds), those would be reasons for Rubyists to love Swift. Much in contrast, similarity might not be the most compelling reason to switch to something different.

heydenberk 11 years ago |

Optional binding in JavaScript is a misfeature, and Ruby's looks that way too, because 99% of the time when you do this:

    if (hasAccess = true) {
        doSomething();
    }

you meant to compare, not assign. So when I saw this Ruby example, I was not amused:

    if current_user = find_current_user
       notify_user(current_user)
    end

However, the Swift equivalent is the best of both worlds:

    if let currentUser = findCurrentUser() {
       notifyUser(currentUser)
    }

chc 11 years ago | |

The thing that's interesting about optional binding is Swift is that it is a special construct for unwrapping optionals, not a normal assignment. If you try to bind to something that is not an optional using that syntax, it won't work. For example:

  if let currentUserIsAuthorized = true { // COMPILE ERROR
    ...
  }

This makes it useful for the one case where you'd actually want it without introducing any pitfalls, because using it incorrectly will be a syntax or type error.

angersock 11 years ago |

  if current_user = find_current_user
    notify_user(current_user)
  end

Funny to see an anti-pattern in C/C++ so lauded in another community.

Also, you know what I like about Ruby? I can write it and it'll run everywhere, and it is maintained by a vibrant community effort. Where's that on this list?

Karunamon 11 years ago | |

You realise that you're talking about a prerelease, right? The language hasn't even been available to developers for a month yet, let alone the general public.

Give the vibrant community effort some time.

jerluc 11 years ago | | |

I could be wrong, but I believe the parent is referring to the inability for a "vibrant community" to maintain Swift as a language implementation (instead of Apple), which is very different than Ruby. There's no doubt in my mind that there will be swarms of people developing with the language, but AFAICT, we'll mostly only see Apple developers working on the language itself.

yxhuvud 11 years ago | |

It is just as much an anti pattern in Ruby as well.

While I can think of usages where I could see myself use it, the given example is definitely not one.

mcosta 11 years ago |

Why Rubyist Will Love Swift? Because Apple has published it.

Disclaimer: I have walked the tutorial and reference and I belive it is fantastic. I am waiting for someone to release a linux compiler.

sigzero 11 years ago | |

That might be a long while.

asolove 11 years ago |

The comparisons with scala and c++ are stronger. This is a large language, with a lot of complexity from having to maintain compatibility with an existing environment, plus lots of new concepts bolted on top. Like those languages, the time to basic proficiency may be faster than with their predecessors, but the time to mastery will be much longer.

tendom 11 years ago | |

Scala, yes, but not C++ at all. Indirectly from C#, perhaps (and there is a fair bit of that), but there is very little that borrows from C++ at the language level.

Glide 11 years ago | | |

Oh I would love to see a write up comparing it with Scala idioms. As a person who has done C# for a while a lot of idioms translate very well to Swift.

The if let x = whatever {} syntax in Swift is damn brilliant after looking at a ton of C# code with the as check.

Karunamon 11 years ago |

As a wannabe-rubyist who thinks reading Obj-C is somewhere between having a migraine and using H2SO4 eye drops, so far I'm in love with the language. I'm doing lots of tripping over the Cocoa APIs, though, in no small part due to Xcode.

The error messages you get when you've done something wrong are unintuitive at best and downright misleading at worst.

Example: I've got a field I want to render an image in. It's represented as an object of type NSImageCell.

I've got my image file defined as an object of type NSImage. So far, so good.

I type the . after the image cell, and I'm presented with a number of autocomplete suggestions. One of which is a method called "setValue" which accepts an object as an argument.

Okay cool.

    myCell.setValue(NSImage(named: "myImage"))

Compile and.. instacrash with "Unrecognized selector"

What?

Some research turns up that this error means you've tried to send a message to (call a method on) something that doesn't accept that type of message.

Turns out that the method I needed is called setObjectValue. And it also accepts an object as an argument.

So, Xcode. Why did you give me setValue as an autocomplete when it isn't valid on that object? Why are these method names nearly identical? facepalm

And that's before I get into the almost completely worthless inline error messages. "Cannot convert to $T1". What?

I really, really like the language, but Xcode is trying its damndest to turn me away. I've got a stack of bugs/feature requests that need to be entered into Apple's reporting tool - hopefully some of these are just warts that'll get fixed as Xcode 6 comes out of beta.

allsystemsgo 11 years ago | |

It's still in beta dude. Night and day difference between beta and gold master. If you're turned away from a brand new language due to an IDE's autocomplete, then you're in for a world of hurt when you start learning all the Cocoa APIs.

galfarragem 11 years ago |

I'm not a rubyist, neither I am a professional programmer, but I'm sad that Apple didn't/couldn't choose Ruby as their main language. Nowadays I'm deciding what programming language to learn as a hobby. Reality (market) tells me that should be JavaScript or right now Swift (looks like javascript for me). It makes me sad, I wish it could be Ruby. So clean and clear. Everything makes sense, I don't need to memorize almost nothing.

Edit/Disclaimer: My first contact with programming (besides BASIC) was Autolisp (Autocad scripting) and my professional field is design.