Sunday, 26 June 2011

2009 Languages Overload

This year (or more to the point, that year, i.e. 2009) was for me a year of languages. Or maybe better, of languages overload! While I'm earning my bacon mainly with C++ (and a bit of Python), this year I had a look at a couple of new languages (adding to my last year's Groovy adventures) like: C# 3.0, Go, Scala, Clojure and even a bit of Haskell. In case of Haskell I'm feeling rather guilty, as I wanted to keep myself busy with Haskell this year but didn't manage more than some superficial reads about monads, and only becaue I needed to explain some Clojure code! Shame!

1. Java

But let me first comment on another language, which is ly dying these days: Java. Is it really dying? Looking at this post by codemonkeyism you'd say so. Why don't we like Java anymore? Let me cite:
Inheritance: outside of frameworks, inheritance is inflexible, leads to tight
coupling and is plain bad. Composition is most often a better choice. As are
mixins and traits
Noisy syntax: Lately there has been the enlightenment that too much noise in a language is a bad thing. Java is especially noisy in closures (anonymous inner classes) and generics.
Null / NPE: Null as the default for object references was a billion dollar mistake. An object should by default need a value. Otherwise NPEs will proliferate through your code. Newer languages prevent nulls or make the null behavior the non default one
List processing: As shown by functional languages, list processing should not be done
in loops. ... Java should have native support for easy list processing, not via the – best we have – constructs in Google Collections.
For me the 2nd problem is the worst, i.e. the noise. It's appalling how much of the Java boilerplate can be thrown away - check this presentation to see how much can be done with Groovy! But each of the new languages does a pretty good job here. Well, to be true, my biggest problem wasn't stated above at all mentionae above - lack of operator overloading! Whatever, the fact is that there's a host of new languages out thre, and the times seem to be more exciting than ever since the 70-ties!

2. Scala

Programming in Scala: A Comprehensive Step-by-Step Guide, 2nd EditionScala seems to be a language having every single feature from any language known to man. The overall impression was: OK, I know that one from ... One single feature I liked is the solution to the multiple inheritance conundrum (you know, the Deadly Diamond of Death) by linearization of the base classes. Clean, efficient, impressive! From the above list it's solving the Null/NPE, noise and inheritance problems. But the syntax is ML derived! Hate it! if this is a Java replacement, why cannot we stay in the old good C-lands? Another problem with Scala is poor tool support: I wasn't able to get the Eclipse plugin running, despite applying various workarounds found on Scala's homepage and upgrades of both the platform and the plugin. Even Martin Odersky (Scala's creator) is using Emacs for work!

On the other side, I think Groovy solves the list processing more elegantly, and it's DSL capabilites are more convincing too! (example to come)

3. Clojure

Programming Clojure (Pragmatic Programmers)I like Clojure! I don't know why. It's not typesafe, has Lisp-y syntax and very complicated mechanism for integration of Java class libraries, but it is somehow elegant and minimalistic. It includes mutithreading primitives in the language definition and it tries to achieve good performance while staying immutable!

As I watched this presentation by Rich Hickey I noticed one important thing: he's an architect who was facing design problems in complex real life systems* (somehow like me, although I must admit that he's been exposed to more complexity than me) an tried to find a solution. And he really knows his stuff - all the conventional wisdom of software architecture! And Clojure (and Clojure's features) is an answer to these problems: it takes from LISP what seems suitable and isn't afraid to change it** otherwise.

Contrast this with Scala - sometimes feeling like an academic exercise in trying implementing all the features known to man in a single programming language just to show that it can be done (caveat: totally subjective opinion here). Maybe this pragmatic legacy is one of reasons why I like Clojure much more then Scala.

4. F# (and C#)

C# 3.0 Unleashed: With the .NET Framework 3.5C# seems to be evolving very rapidly. From the ugly duckling it was a couple of years ago, it developed a respectable language with a decent amount of innovation. It has good lambda function support and the LINQ concept is rather interesting. I was surprised!

F# in its turn seems to be syntax-wise another ML derived langage like Scala, but it's not so overloaded with features. Sorry, I'm still not done with the free F# book...

Some (for example Scala Lift's creator here) say that it could be the single one of functional languages to success in the mainstream!

5. Go-lang

I didn't like it that much despite of its heritage. The obligatory, one and only true formatting rules, lack of subclassing... But on the other side, there is a CSP implementation on the language level! And as another programmer, who actually tried it out, stated here, it's much like writing in Python, only without its excruciating slowness. So maybe I should switch from Python to Go? Google Application Engine supports it now!

in the meanwhile I managed to have a look at Go!

6. Summary
Warning: You see, it's not the comprehensive comparision I wanted to write back in 2009/10, but before I ditch the project altogether, I'd rather write this stub and extend it when I find some time. But the summary is already complete now, so... ---->
As I said above, I'd use Scala as a "better Java" as to avoid Java verbosity, lack of operator overloading and multiple inheritance. I'd use Closure for the joy of if (pun intended), I'd like some of my clients to want me to use Go, but wouldn't propose it myself, and I probably won't use C# unless I switch to .NET which is rather unlikely. On the other side, I might install F# on my PC - just to play with it a little.

* according to InfoQ "...Rich has worked on scheduling systems, broadcast automation, audio analysis and fingerprinting, database design, yield management, exit poll systems, and machine listening."

** e.g. even the venerable parentheses!

Exegi Monumentum...

"Exegi monumentum aeris perennis"* - I don't know why but this line is always coming to my mind when I'm thinking about my father, who passed away more than 2 years ago. Just because he was fond of classical studies and Latin?

He also cherished that other lines of poetry, in a language that you can't possibly know, but which, as I can assure you, are work of a genius (I cite form memory):
"Wsrod takich pol przed laty, nad brzegiem ruczaju,
na pagorku niewiekim, we brzozowym gaju,
stal dwor szlachecki, z drewna, lecz podmurowany,
swiecly sie z daleka jego biale sciany,
tym bielsze, ze odbite od ciemnej zieleni,
topoli, co go strzegly od wiatrow jesieni."
You're right, that's a single sentence. And he could recite one after another in the endless flow of the language. Yes, you are right again, this is a hommage to my late father, which I'm writing 2 years too late. The first thing I'll always associate with him will be the classical poetry. The another one, linked via the above phrase of Horace, is a story of an interview and things which it revealed to me in retrospect.

It was my school appointment to interview someone and I choose to interview my father. I remember just a single question I asked: what do you want to be remembered for? The answer was somehow unexpected to me: he cited the line of  Horace, and said: I want to be remembered for the things I accomplish. And he did, he was working in local political bodies and was involved in building roads and water supply lines in our rural neighbourhood.

So when it came to finding a vocation, I wanted to build things! Not maths, physics, literature or music (things I was interested in), but engineering!

As for us in life there are 2 things which are worth of pursuing: for yourself, trying to understand the great scheme of things in that world (for practically minded, if you are more ambitious it's the universe then). But secondly, you owe it to the others, those before you and those to come after you, to keep the world running smoothly, and build new smootly running things to replace old ones.

I think, that's my father's heritage. And that's why I cannot be a geek - because I grew up listening to poetry, looking at nature of the rural coutryside and experiencing very practical achievements in very real world.

* fom Horace, translation mine: "I build a monument [to stay] for perennial ages"

Monday, 6 June 2011

Agile Rant Update

After you've read my Agile rant you may have though: "just another old-fashioned hacker who just doesn't get it...". Fair enough, I'm myself not that sure if that what I'm saying isn't just result of lack of experience with Agile? Maybe with even more exposure all my reservations would vanish?

So I'm happy to find out that there are other people thinking roughly along my lines. For example here: Agile Hokum, in DDJ reader mail. He (the reader)says exaclty what I said:
But the "TDD corrupted by writing the tests after coding" is about as extreme as the Taliban. Testing is good. Write them before, during, after, much after, etc., all have their place.
and doubts usefulness pair programming as well. The standard TDD answer of the expert goes than like that:
I agree that tests written at anytime will generally have value. However, TDD was not designed as a way of validating code — plain unit testing will do that. TDD is first and foremost a design practice. And so doing TDD by writing the tests after the code is simply a misunderstanding of what you’re actually doing.
Well, that opinon is already dealt with in my Agile rant. But taking the simplistic road I'd just say that's the way it is handled in agile projects: not as a design technique but rather as a testing one. OK, here seems to be some confusion on the term itself: it's either Test Driven Development or Design...

On the other side the author (i.e. the reader) openly admits that he's not an Agile practitioner, so that opinion doesn't give any earnest support for my criticism?

But look what an ex Googler says here:
This is not to say that all unit testing is bad--of course not. The dispatch logic in Guice Servlet and Sitebricks benefit from rigorous, modular unit tests. If you have ever used Gmail, Blogger, Google Apps, AdWords or Google Wave (all use Guice Servlet to dispatch requests) you have seen the benefits of this rigor first-hand. But take it from me, we could have achieved the same level of confidence with a few well written unit tests and a battery of integration tests. And we'd have been in a much better position to improve the framework and add features quickly.
That strikes a chord with me, because it's exactly the way I tested my last system - a lot of integration and pre-integration tests, and a couple of unit tests for classes which couldn't be easily tested thorougly that way. Wouldn't that be allowed at your company? Because this isn't Agile?