Programming in the Ruby Language

ShoeHorn writes: "Here is a good article (1st of a 4 part series), that introduces you to the Ruby language. If you are currently a programmer coming from the likes of C++, Perl, or Python, you will see some strong similarities (especially to Python)."

Comments

Why worry about importing IT workers,

[niekze]

when you have to deal with another stupid language every 6 months. You should only need 3 languages:

Pick one from each of the following:

(C/C++)
(Perl/Tcl)
(sh,ksh)

Now for the 'bonus' round. [pass go and collect $200 more a month]
(php,python)
and for the MS route, you only get 3:

(C++/C#)
(Visual Basic/there is no other option)
(Java/no other language is as useless to compete with Java)

Now...how far off am I?

Re:missing the point

[rowland]

Wow! I nominate you for the "Sweeping Statements Award." I especially like the way you say "The object models of Python, Perl, and Ruby."

So far, I haven't heard anyone nominate these languages for "large system development," but a lot of large systems are made out of small systems, and while it is tempting to create these large systems in a uniform language (*cough*)Java(*cough*), this can be a mistake. I read a magazine article recently about a shop where they were replacing shell scripts with Java for automating tasks--which turned out to be a big mistake, considering the overhead of the Java VM.

You're right about compilation to native code being of limited benefit to these languages. For the most part, it is a "benefit" they don't need. Take, for example, creating a complex web site in C or another statically-typed, and therefore easily-compilable, language. By the time you're on your third page, you'll realize you need some kind of templating system. Next, you'll discover you need to vary the appearance of pages based on aspects of your business logic, so you add conditions to your templating system. Next, you'll find management wants to be able to update the site quickly using cheap HTML monkeys and is reluctant to spend expensive programmer time recovering old ground, so you make the site entirely data-driven. So now you have a buggy, ad hoc, poorly-documented excuse for PHP! Sure, the code you wrote is compiled, but the system as a whole is slower, and it took a whole lot longer to write.

You said, "If the scripting languages ever evolve into something like Lisp or Smalltalk, their object models, syntax, and semantics will have to change dramatically and incompatibly."

Have you ever considered that maybe these languages ARE the evolution of Lisp and Smalltalk? With all due respect to Lisp and Smalltalk, their creators didn't have the benefit of Lisp and Smalltalk when creating their languages. Larry and GVR and Matz didn't create their languages in a vacuum. Even PL/1 must be of benefit to current language designers (here's what NOT to do!).

Perhaps it would be of benefit to aspiring language designers if you could elucidate exactly how "objects models, syntax and semantics" could be improved and what the benefits would be--keeping in mind the purpose(s) of these languages.

Granted, the best programming language doesn't always win out, but the purpose of evolution is to thrive, or at least survive. I am therefore equally suspicious of praise for highly-evolved-yet-dead languages and snubs of unevolved-yet-wildly-thriving languages.

Brent

Re:Why learn another language?

[helixcode123]

I appreciate and share your view that by learning multiple languages you enlarge your toolbox, and in the big picture all languages are intertwined. (Jeez. I sound like I'm rambling on about "The Force" or something.)

I've noticed a similarity in my "night job" as a musician, where playing different types music acts in a similar way to programming in different languages. You pick up stuff in one style that can enrich your playing of another style. Well I sure am staying on topic, eh?

One comment I wanted to make regarding Picking up another language in a day. I agree somewhat. There was no question that after programming in (time order) Pascal, C, Fortran, Ada, Lisp, Clips, and Scheme I was able to "pick up" Perl pretty quickly. That said, it took some time to really learn the Perl idioms and to do things in the "Perl Way". I've seen my share of C code that was really Fortran written in C, or Java code that was really C written in Java (procedural vs OO). With appologies to Heinlein, it takes longer than a day to grok a new language.

Re:I think this said it all...

[RevAaron]

Speeds up development my arse.

Heh. Does perl speed up development? Everytime I've tried to use it, I had to have multiple browser windows open for docs and other people's code, in an attempt to figure out what the hell it's goofy syntax stood for. The small script I ended up making kind-of worked- doing the same read, search-and-replace, and write back to file only works some of the time on some of the files- I try it on a different and directory and BAM it doesn't work!

I'm not saying perl is completely flaky and useless- but contrary to Wall's silly assertions, perl isn't a language you can pickup gradually, there are simply too many rules and funny symbols ($/, @_, $_ anyone?) to learn just to do simple things.

And why the hell can you only store scalars into hashes? Pffft! And don't tell me I can just use references to non-scalar data, as refs are scalar- if I wanted to deal with C's bullshit, I would.

15 languages is enough.

[Futurepower(tm)]

I'm just guessing, but I think I have learned at least 15 programming languages. Maybe it is 30, if you count assembly languages. At some point, learning languages must come to an end. At some point, I would like to see all the good features put into one or two languages. I have no intention of using my life learning languages that then die very quickly, like Pascal.

It seems that, at some point, every skilled programmer becomes interested in writing either an editor or a computer language. I wrote one myself, for use with some H-P data acquisition equipment. Now both the equipment and language are obsolete.

With every new language, there are years of extending the language, finding and curing the bugs, and wrestling with incompatibility problems. At some point, this must stop.

Language writers should put their creativity into extending C++ rather than abandoning it.

Consider Java, for example. There have been literally years of hassle and discussion about Java, when it could have been implemented merely as a compiler switch to a C++ compiler. The compiler switch could have provided automatic garbage collection, given error messages for use of pointers, and provided the other features of Java.

Microsoft, following its usual abusive practices, put many ease-of-use features into Visual Basic, while keeping them out of Visual C++. The result was that there are maybe 1,500,000 programmers who know Visual Basic, but don't know a real language. And what language is Visual Basic itself programmed in? C++, of course.

When you write in Visual Basic, you are just a dog on a leash. Anytime Microsoft wants to yank your chain, it can. If Bill Gates happens to lose interest, Microsoft can kill this one-OS language, the way it killed xBase (dBase, FoxPro), for example, by making quirky additions that no other vendor could/would follow, and then abandoning development.

It is a shortcoming of the U.S. culture that so many men feel that they must play King on the Mountain, and try to knock everyone else down, rather than cooperate.

Like everyone, Bill Gates has inner conflict. But don't let his anger and obsessive desire to make money reduce the quality of your life!

So now it is Ruby, supposedly the next big thing. How long will it be until the books are all written? How long until we discover the shortcomings? Is there some feature in Ruby that can't possibly be added to another language?

I reviewed Ruby a little about a year ago, but came to the conclusion that the documentation was extremely poor. The overall value of a language is the value of the language itself, plus the quality of documentation of the language.

At some point, I want the merry-go-round to stop, so that I can get off.

Is there something in C# that simply could not be made a compiler switch to C++? Do we really need more syntax? I'm not saying I know all the answers to some of these issues. But I sense that something bad is happening.

For a few years, languages were interesting to me. But now, I just want to do the job, not discover other ways to do the job. Let's move on, rather than repeating what we have done before. Let's improve what we have, rather than starting again.

Re:15 languages is enough.

[rowland]

"For a few years, languages were interesting to me. But now, I just want to do the job, not discover other ways to do the job. Let's move on, rather than repeating what we have done before. Let's improve what we have, rather than starting again."

You sound like a guy I work with. I sympathize with him, because he's getting close to retirement. Maybe you are too. I think it was the "Pragmatic Programmers" who said you should learn a new language every year. I find it helps to keep the brain plastic. It's all too easy to get into ruts, but soon the joy is gone too, and you might as well be flipping burgers.

Brent

Re:Why learn another language?

[StrawberryFrog]

Great post, but IMHO any 3-year CS course that aims to teach only one language is going about things completely the wrong way.

You should spend time in (for e.g.) a simple teaching language to start off, 1 mainstream procedural/OO language, one functional language, one scripting language and study briefly a sampling of languages of comercial or academic interest, and what makes them interesting or sucessfull.

IMHO when you learn your second language is when you start to 'get it' about what is an essential feature, and what is an accident of syntax or history in programming.

I wouldn't call knowing only 1 language a "the Computer Science Student mentality" because a CS graduate should definitely not know just one language - they should know how to pick up any language quickly, having had practice at it.

Other languages teach other ways of thinking.

[Futurepower(tm)]

In the second half of his post above, Dalroth has made a very sensible case in my opinion, for learning other languages.

(Dalroth seems like the kind of programmer employers want to hire. But he has provided no way to contact him. In fact, he is very negative about being contacted in his bio.)

I'm tired of new languages (read my post #128), but Dalroth has a point that other languages sometimes teach other ways of thinking.

The answer seems to be to put all the knowledge in one place, or as few places as possible. At some point even Dalroth will decide that one more language is too many.

Re:Strict languages vs. hacked languages

[Hrunting]

Usually the latter turns out to be some baroque conglomeration of features piled on features, creating a very top heavy feeling to the language, while the former classification languages all have a purity to them, e.g. smalltalk, lisp, and c.

Well, I mean, as long as we're talking in generalities here, the latter also seem to be geared towards getting jobs done where the former are geared towards elegant problem-solving. Purity is great when you're admiring something, but no one wants to hang out with the righteous virgin when they feel like getting laid. Personally, when I program, I'm not looking for my code to fit some elegant theory. I'm looking for the job to get done as succinctly as possible.

Some would defend the "hack languages" as a means to Rapid Application Development, but Smalltalk has been shown to be the most productive language, and Ruby/Python/Perl all seem to me to have a BASIC odor to them; I'm wondering if people are afraid to learn a new way of speaking?

I would say that Perl stinks more of shell and C than it does BASIC. If you're talking because it has a lot of built-in features, there are plenty of languages that have it. But out of all the languages you've mentioned, I found it ironic you say that because Perl has problem undergone the most intensive language development of any (and the new process probably blows efforts for other languages out of the water). Larry Wall has a great affinity for languages (both spoken and programming), and it shows, because, for English speakers, Perl is designed so that you can write it like you almost would speak it. Now, you might say that that is "hack"-ish, but that shows a lot more care for the process of programming than a language that idealistically sticks to a theoretical truth in favor of making the language easier to use.

And provide a link to a study that shows Smalltalk is the most productive language. I'm not saying I don't believe you, but I personally find the "hack languages" to allow a much more natural flow between my brain and the screen, so I'd be interested in seeing how that conclusion was reached.

Re:Strict languages vs. hacked languages

[smallpaul]

I get the stronger sense that you don't know Ruby -- most Rubyists tend to be ex-Pythoners and not the other way around, but nevermind.

People do tend to progress from more well-known languages to less well-known ones. They don't go to a bookstore and pick up a K book and think: "this would be a good first language." I've played with Ruby enough to decide that it is neat but not appropriate for many of my projects and not a sufficient improvement over Python for the rest.

Python lacks metaclasses, lacks a true unified object hierarchy, and supports multiple inheritance (considered a very bad idea by most experts in OO. Like the "goto" statement, multiple inheritance may seem useful at times but it leads to unmaintainable code). All these are simple repeats of the mistakes of C++.

Python 2.2 has metaclasses, a unified object hierarchy and supports multiple inheritance which is quite useful and safe when used thoughtfully.

It is simply a matter of historical fact that Python was not based upon C++. If it shares features with C++, those would probably be traced back to Simula through Modula-3. Smalltalk is also based upon Simula.

Yes, Python is improving, but all these improvements (like allowing the subclassing of primitives) only serve to point out flaws in the design (why aren't primitives normal objects in the first place?)

Nobody would claim that Python 1.0 was perfect, nor that Python 2.2 is perfect. Nevertheless, you haven't yet mentioned a feature of Ruby that isn't in Python 2.2. There certainly are such features -- but they get increasingly esoteric as Python improves. If I have to choose between Bertrand Meyer-approved-OO-cleanliness and native threads that don't block when you do I/O, I would choose the solid threads. OO-cleanliness is about conceptual elegance and native threads are about getting the job done.

And how deep is Ruby's Unicode support? If you can please point me to documentation on using Ruby's regexp engine to match Unicode characters, I would appreciate it.

My current Python projects depend heavily on both threads and Unicode. Mixins, multiple inheritance and the ability subclass "integer" really don't matter one whit! I am mostly happy that Python is unifying its type system for rhetorical reasons. Practically it hardly matters at all!

If you want to impress the vast majority of programmers who are not language collectors, you'll have to show us some program that are hard to solve in (e.g.) Python and easy to solve in Ruby.

For this and other reasons, it is not accurate to paint Ruby as the next step after Python. It is another good language with strengths and weaknesses. One day it will have a superset of features that Python currently has...but Python will itself have evolved by then.

so many choices

[RestiffBard]

I'm just learning python now. There just aren't enough hours in the day for me to learn all of these languages.

Re:so many choices

[Ghoser777]

There isn't enough hours in the day to learn every tongue used around the world by people either. The amount of languages is a partial indicator of the diversification of programming. Each language brings something different to the table. French, Spanish, German, Russia: they all have their different connotations and ways of expression. It shouldn't necessarially be your goal to learn all these languages, but choose the language that best meets your needs. And hey, having that Ruby reference book can be as useful when you get in a jam as when you end up in Mexico with an English-to-Mexican and vice-a-versa dictionary.

F-bacher

Re:Why learn another language?

[RevAaron]

That is, for the most part true, but there are languages that make it difficult and some that make it easy. For me, no matter how much I am forced to use it in school, C++ is still a lot harder to express ideas (especially well-designed OO ones) than some of the other languages I know. This is for a lot of reasons, from syntax to manual memory management. Now, it's not that what I want to do is impossible in C++, but there's a lot more crap I have to think about and deal with to get the same basic stuff done.

Re:Why learn another language?

[Anonymous Brave Guy]

The simple fact of the matter is, if you know one language, you know them all.

I was about to object to that, but then you wrote...

Unless you are making the jump from procedural to OOP, or OOP to Functional for the first time, you *CAN* pick up a book and learn a new language in a days time. The only thing stopping you is yourself.

Thank you for being one of the few to acknowledge that while languages using similar ideas may be easy to learn once you know the first, languages using fundamentally different approaches might take some effort! Sadly few people seem to realise this.

Having said that, I'm afraid I have to disagree with your "one day" as well. You can learn a new syntax in one day, sure. But how long does it take to learn the new idioms? Java and C++ have similar syntax, but Java uses a GC and finally for resource management, while C++ has predictable destruction and uses the abysmally-named-but-rather-neat "resource acquisition is initialisation" idiom. Anyone working seriously in these languages needs to appreciate this distinction, but it's not written down in (m)any of the books.

Re:Strict languages vs. hacked languages

[Jonathan]

And how deep is Ruby's Unicode support? If you can please point me to documentation on using Ruby's regexp engine to match Unicode characters, I would appreciate it.

Here you have an issue of implementation, not design, but at present a legitimate issue. Ruby is a product of Japan, and ironically, from the perspective of Westerners, who generally see Unicode as a sort of peace offering to Asians to make up for the dark ages of ASCII, the Japanese hate Unicode and prefer their own multibyte solution. So, the status of Unicode in Ruby is somewhat primitive at present. However, as Ruby was designed with multibyte characters in mind, it should be much easier to improve the Unicode support than in other languages.

Re:missing the point

[RevAaron]

Have you ever considered that maybe these languages ARE the evolution of Lisp and Smalltalk? With all due respect to Lisp and Smalltalk, their creators didn't have the benefit of Lisp and Smalltalk when creating their languages.

I would definately agree that it's evolution, however, it's not a controlled evolution pointed forwards, like the evolutions that created Lisp and Smalltalk.

Python, Ruby, and others are adaptations of Lisp and Smalltalk to a way of thinking that people used to C and Unix can handle. Smalltalk and Lisp are too advanced and forward thinking that languages like Python and Ruby have to take a forced step backwards to accomodate those who cannot advance. It's kind of sad in a way, but I suppose it's still a step in the right direction, as there's a better chance of converting C++, Java and Perl people to Ruby than converting them to Smalltalk or Lisp, unfortunately. Better part way than none!

Time for an icon....

[jeffy124]

I think it's time for Slashdot to draw up an icon for Ruby topics. This story is about the 5th maybe 6th Ruby related item to appear on /. in the past few months. A simple picture of a good red-ruby you would find in a jewelery store would do fine, such as one of these. Anyone for it? Against it? Got a better pic to use?

missing the point

[mj6798]

If Python was the result of Lisp and C++ having a baby, Ruby is the result of Perl and Smalltalk having a baby.

The key features of Lisp are the use of a uniform notation for programs and data, a notation that makes it very easy to write syntactic extensions, and full support for functional programming. Python 2.1 now has some limited support for lexical closures, but users almost never extend its syntax. The key feature of Smalltalk is its programming environment. As a language, Smalltalk's main feature is the use of very descriptive method and argument names. Neither of those is shared by Ruby.

Python, Perl, and Ruby are nifty little scripting languages, but don't think for a moment that if you are using them you are using the next generation of Lisp or Smalltalk. The object models of Python, Perl, and Ruby are general but slow and memory intensive, their programming environments are oriented towards scripting, not large system development, and compilation to native code, when it exists at all, is of limited benefit. If the scripting languages ever evolve into something like Lisp or Smalltalk, their object models, syntax, and semantics will have to change dramatically and incompatibly.

Re:Strict languages vs. hacked languages

[Peaker]

I agree Ruby and Perl seem to be like the latter type.
Python, however, is a truly clean, well-designed, quite-pure, strong-typed language.
I wouldn't say it has a Basic odor at all, besides for a built-in 'print', perhaps :)

Basic is braindead and has no library - instead, it has its entire library built into its syntax in a horrid way.
Python is the exact opposite - many many libraries separated into modular modules, with only flow constructs, OO organization, functions and exception handling built in.

Re:Strict languages vs. hacked languages

[FFFish]

FWIW, within a week you'll learn to love whitespace. Yes, it imposes a visual "order" to your code. You'll soon appreciate the consistency: you can look at other code and immediately make sense of it, without having to mentally adjust for the other programmer's weird habits.

Re:word math

[ConsumedByTV]

but is there anything wrong with making it a simpler operation?

Okay, it looks simple enough..

[jcr]

..so, what does it offer over Python once you get past "Hello World" * 3?

Is there anyone who can fill us in on why this language is worth using?

-jcr