[Fwd: Re: Functional Programming in the Larger or Functional Oriented Software Engineering]

Joe Marshall wrote:
> I've also debugged a lot of complex programs.  *Many* *many* bugs
> are the direct result of someone modifying something that someone
> else didn't expect to be modified.  Large complex systems spend
> a huge amount of time copying structure to protect themselves from
> accidental mutation.  Look at a large system coded in Python and
> see how much time it spends in deep-copy.
>
> Given how many bugs and kludges I've seen to work around bugs
> in a stateful system, and given that I've seen a number of large
> complex systems that are state-free (and simply *cannot* exhibit
> state-associated bugs), I've started to rethink this idea of `state
> is bad'.  I'm coming to the conclusion that state is *far* worse
> than most people think, and even the rabid Enemies of State
> are underestimating it.
>
> On the other hand, I don't think `world-passing-style' (monads)
> are the solution, either, so I'm not quite ready to jump on
> the absolutist platform.
.....
>
> Now it may be the height of wastefulness to tell people that if they
> if they want to change the color of their car that painting is not an
> option --- they must purchase a brand new car of the correct color,
> but if you have the resources (if cars are cheap or free), this really
> isn't such a bad option.
>
What if resources aren't cheap, or I have to manage my own memory.  Is 
avoiding mutation still practical?

Matt

-- 
"You do not really understand something unless you can explain it to your grandmother." - Albert Einstein.




-- 
"You do not really understand something unless you can explain it to your grandmother." - Albert Einstein.