Re: [Axiom-developer] Must hear...

[Martin Baker]

On 11/05/14 21:33, Tim Daly wrote:
> Unless there is some overarching reason it is hard to see the need to
> rewrite existing code. A new design that regularizes many domains
> might make a good reason. A complete extension of the whole area, such
> as a major matrix package might make DHMATRIX a useless subset. But
> changing the API of an existing domain so that old code doesn't work
> is, by definition, broken.
>
> Mistakes in the code will occur both in old code and in new code.
> Unfortunately new mistakes are only likely to be uncovered by new
> people using the new code... which by recursion on the motivation
> to rewrite the code...  leads to yet a different set of mistakes.
>
> Code doesn't rust. It doesn't "get old". Especially computational
> mathematics code. Tearing down the cathedral because we now know
> how to make stones that lasts longer seems ... I don't know ...
> disrespectful of the genius of the original architects?

One of the ideas I seem to be getting from the Robert Lefkowitz talks is 
that most of the life-cycle of a piece of software is in maintenance 
(i.e. change) and that is why this type of documentation is needed. It 
seemed to me that a corollary of that is that, if the code does not need 
to change, then documentation is not required.

The thought also occurred to me that the wider axiom community has two 
types of factions, those who want to change without documentation and 
those who want to document without change. I don't mean this to be taken 
seriously, its totally unfair of me to write down such an untrue 
thought. I apologise unreservedly to people who are working very hard to 
improve a program they believe in strongly.

I agree about the genius of the original architects who were years ahead 
of their time. I think more history should be made available to let more 
people know about this.

However I don't want to use, or work on, software that is a museum or 
shrine to the genius of the original architects. I have convinced myself 
that the sort of changes, that I would like, are driven by real needs to 
support new mathematical structures and so on and not just a wish to 
tweak the margins of the program for the sake of it.

see my wish list:
http://www.euclideanspace.com/prog/scratchpad/fricas/wishlist/

I think what you are hinting at is that the original scratchpad software 
was written by a large number of brilliant people and I am a single, 
humble individual who is very far from being a genius. I assure you, I 
know that already. I really should set myself more realistic goals.

It seems to me what Robert Lefkowitz is saying is that programs need to 
change over time, and for that they need documentation and of course the 
meaning of the word 'documentation' changes over time and everyone 
understands the meaning of words differently. Mathematical truth may not 
change over time, but the way that people use it, what is considered 
important, notation and just about everything else does change. Perhaps 
'documentation' does not mean what I think it means but, for me, its 
about not freezing the program in time.

Martin