[REBOL] Re: Speeding up code
From: sunandadh:aol at: 13-Feb-2002 10:23
Hi Joel,
> I'd refactor the code to separate the behavior of an individual
> watch (as an object with its own state) from the behavior of
> the total collection of watches in existence at a given time
Thanks for the complete rewrite. It's always useful to get a completely
different view on how to do something, and I hope that between us we've
produced some functionality that is of use to others.
A few thoughts about the difference between object+functions and
function+refinements, inspired by your rewrite.
Object+functions of course give a lot more room to breathe -- it is easier to
have persistent variables in them than it is with function+refinements.
>From the outside there is almost no difference between calling an
object/function and a function/refinement. If I rewrote my code to be an
object but with the same interface, you couldn't tell the difference from
seeing the invocation:
>> unit-timer/start "A code unit"
I say _almost_ no difference for two reasons:
01 -- In the original code, an invocation without a refinement executes the
code and returns False:
>> print unit-timer
== false
If it was an object, invocating the object name alone returns the object:
>> print unit-timer
?object?
There is no implicit init code for a Rebol object.
02 -- Help Unit-timer in the original returns an "overview" plus help for
each refinement. If Unit-timer were an object, there'd be no obvious place
for the overview. And I don't know any easy way of getting help for a
function embedded in an object --
>> help watchmaker/start
watchmaker/start is a path
(This seems an obvious design oversight that RT could fix one day).
Objects of course don't just give more room to breathe, they open an
opportunity to work in a quite different way. Your code is a good example of
this in that it assigns the functionality to user variables. I'm not sure
what this next example does to your collection and report-all, but if I want
a timer than lives on between program runs, I can do it with your code:
LongTime: watchmaker/new "long-life"
Longtime/start
...
Longtime/stop
write %longtime.wat mold longtime
......
Longtime: do read %longtime.wat mold
longtime/start
(This would be more useful if the function worked across midnights)
One tiny question. You have a to-seconds function I just use to-decimal. Any
significant difference there?
Thanks again for the rework,
Sunanda.
