Re: Is strong typing worth the cost?

[Darren New <dnew@san.rr.com>]

Wes Groleau wrote:
> 
> > You've still implemented the stub. To run the test, you still have to
> > code the declaration of the subprogram and you still have to code the
> > body of the subprogram. The body doesn't have to be *right*, but it
> > still has to be coded.
> 
> I must be missing something.  Why do you want to
> run a test when the item being tested doesn't
> exist?

Already addressed with at least two examples. See the other XP papers.

> > count "won't compile" as a failed test, but since XP uses Smalltalk and
> 
> I avoided saying it until you brought it up, but
> in the limited reading on XP that I've done. it
> continues to look like a methodology designed to
> promote Smalltalk and to not work with anything else.

Errr, no. Only someone who thinks it's trying to promote one language at
the price of another would think that. Smalltalk fits very well with XP,
and the folks who invented XP (or at least who first popularized it) use
Smalltalk to its best advantage. 

> If "extreme programming IS Smalltalk" why fault Ada
> for not "fitting in" ?

Where do I "fault" Ada? I'm simply saying that Ada doesn't seem like it
would work very well with XP to me. Nor would I use Smalltalk in a
safety-critical real-time embedded system. Is that a fault of Smalltalk?
 
> > > Why not make a hundred copies of the program each cycle,
> > > make random changes, and keep the few that look promising?
> > > Genetic algorithm--sort of.
> >
> > Well, you could, but it wouldn't be XP.
> 
> Sounds like it would be a faster version of the same thing.

Err, no.
 
> > I'm not trying to say XP is superior to the normal mechanisms used by
> > Ada. I'm just saying that *if* you're doing XP, doing it with something
> > like Smalltalk is better than doing it with something like Ada, in part
> > because of the strictness of Ada's type system that requires extra work
> > to make things compile/link and extra redundancy that assures the
> > compiler you mean what you said.
> 
> Since XP and Smalltalk seem to be in a chicken and egg
> cycle, I think "Is Ada bad for XP?" is not a very useful
> question.  A better question would be,

That wasn't the question I'm trying to answer. See the subject line.

The question I'm trying to answer is "is strong (static) typing always
superior to dynamic typing?" (Note that Smalltalk doesn't have weak
typing, but rather dynamic typing, so I'm fudging the question just a
touch to actually address something slightly different.) If the question
is "is strong typing worth the cost", then I'd argue "Not if you're
using an XP development cycle." 

That is, *given* that you've chosen to use XP, which will work better, a
dynamically-typed language or a statically-typed language. I think the
answer there is that a dynamically-typed language will work better.
 
>   "For a particular application domain, does using
>    Smalltalk with XP or Ada with its 'best practices'
>    produce better code sooner?"

And since the OP didn't state their particular application domain, I'd
say this is an impossible questin to answer. And the OP didn't ask this
question either. My only point is that there are times when strong
typing (as the OP seemed to mean it)is not worth the cost. Not that Ada
is good or bad or that Smalltalk is good or bad or that XP is good or
bad.

-- 
Darren New 
San Diego, CA, USA (PST). Cryptokeys on demand.
   The 90/10 rule of toothpaste: the last 10% of 
         the tube lasts as long as the first 90%.