NYCPHP Meetup

[Tim Gales]

 Adam Maccabee Trachtenberg writes
> On Wed, 21 Jul 2004, Tim Gales wrote:
> 
> > Ah yes, the old we'll refactor it later ('packed into a lib 
> later') -- 
> > very similar to we'll document that later.
> 
> XP is a software engineering methodology that removes 
> dependencies in your code and places them upon your developers.
> 
> The only reason you're allowed (required) to write the 
> simplest code possible is that you're required to refactor it 
> mercilessly. Failing to do the second invalidates the first.

If I understand refactoring, it means to rearrange your classes and 
methods so that common code is more easily inherited from or delegated 
to with the goal removing duplicated code (or code which expressed 
another way -- but with identical meaning -- would be a duplicate).

I am under the impression that the goal is to achieve some sort of 
'ne plus ultra' state with no (or very little) duplication of code so 
that you can enhance a routine in just one place (since it is not 
duplicated anywhere else -- or hardly anywhere else).

Mixed in with the methodology is also a concept of delivering 
working pieces of code early. And from what I can make of the 
reasoning behind this is that once users use the working 
pieces, they may change their mind about what they want the 
final system to do.

And so it would seem that one of the lines of reasoning which 
argues for this way of doing things is that you can avoid wasting 
time creating a 'wrong' design initially -- and you should (to some 
degree) discover what the design is, and the design may be changing 
along the way, from building working parts of the system.

In theory I guess this could work. But it strikes me that if the 
deadline for delivering the system overtakes you, you might run 
the risk of delivering a system into production without much of a  
coherent design -- though you would have avoided an initially 
wrong design.

The result would be an awkward system where developers 
would have to memorize the places where pockets of code must updated 
together -- of course this is  something which can happen anyway when 
you do things the 'old fashioned' way.

I will be the first to admit that I don't fully comprehend this method. 
But it just strikes me as fraught with danger -- maybe that's why it 
is called 'Extreme'

T. Gales & Associates
'Helping People Connect with Technology'

http://www.tgaconnect.com