Tuesday, August 19, 2008

Option/Maybe monad is a generic NullObject

I've just reviewed the NullObject and Visitor post. It is so similar with the Option/Maybe monad.
ps. Thought's on Validation: Scala/liftweb has an nice Can.

Monday, August 11, 2008

Scala Marketing Challenge

Josh Suereth would like to improve the Scala's marketing strategy.
This is a tough sell. If we look at the Change Function:

ChangeFunction = F(PerceivedCrisis/PerceivedPainOfAdoption).

(btw. read Erik Meijer's paper: 'Confessions of a Used Programming Language Salesman', it's really, really good.)

So we'll have to ask ourselves what problem is Scala trying to solve, and how much it'll cost. IMHO, Scala is trying to make programming easier. It partially addresses the concurrency problem, but it is not its main-focus, I would say is the ScalaActors are a good side-effect of Scala's good (language + library) design.

What we'll have to pay in order to make the 'switch': the syntax is slightly different. Functions are 1st level citizens. (but functions/closure are scary). Operator overload is also scary (funny enough, method overload is not scary: we are afraid of symbols but we are not afraid of words). Then we have for a good generic support we have 'Generics of a Higher Type', type covariance/contra-variance. Pretty scary... booh! Did I say that IDE support is not yet at java's level?

On the other side we have a huge number of java developers. They are satisfied. Not really happy, not really sad. Ok, java is not that great, but it has been like this for years, why change? To be more effective? Probably to sell that to a manager you'll need 5 independent studies to show that scala is better then java and you'll need at least one big company to push the language. ('if they use it, we could use it too')

Regarding concurrency: a lot of java developers have problems to right correct code, so probably concurrency is the least of their problems. Other developers we'll say 'we have java.util.concurrency'.
If you look at the package you'll see they offer concurrency primitives, and to write shared-state concurrent programs is very hard. You'll have to think a lot more about object isolation and the threading context.

In conclusion:
- UserPerceivedCrisis: small
- PerceivePainOfAdoption: big
ChangeFunction -tends-to-> small.

sorry, scala...

Friday, August 08, 2008

Poka-yoke API Design

API Design should be Poka-yoke.
And if we look what zen aesthetic means to people, a good design is zen: clean, simple, minimalistic.