Jeff,
In his book, Refactoring : Improving the Design of
Existing Code
http://www.bookpool.com/.x/t7itfr3lmm/sm/0201485672 ,
Martin Fowler help programmers tame their java code. I
now consider it the most important book for learning
the Java language.
Your example is excellent and I hope that we will see
more in the future. I have certainly learned alot
about REBOL by refactoring my code many times. Next
time I suspect there is a better way to do something,
I will ask this list.
Regards,
David
--- [EMAIL PROTECTED] wrote:
>
>
>
> There's a certain zen to REBOL and it takes time
> to
> understand-- something that I am always learning.
>
>
> REBOL has a lot of what might seem like idioms,
> which really
> are ways to do things that make life a lot easier.
> They
> stem from the craftsmanship in REBOL, the rather
> lengthy
> effort that went into its design, implementation
> and polish.
> Many problems you face in programming have a
> nicely crafted
> solution sitting inside this little binary
> interpreter, just
> waiting for you to discover it when you need it.
>
> The code that comes from REBOL should demonstrate
> that Zen
> because we all are lucky in that we can pick
> Carl's brains
> over the challenges we encounter. Also, we're
> lucky because
> we get to write REBOL code as an occupation, so we
> get to
> find all those little crafted edges inside. I've
> always
> hoped to pass on what little I have learned of the
> Zen of
> REBOL to any who would walk in that path.
>
> Here is an example of some REBOL Zen style idioms.
>
> ============================================
>
> Consider a block of similar objects:
>
> block: [make object! [name: "foo" phone:
> #222-1111 ... ] ... ]
>
> Now you're writing a function and you have this
> block and it
> is really long with many of the same kinds of
> objects, but
> you need to see if there is an object which has
> the name
> field set to "Waldo" and you need to see if the
> waldo
> object's phone field is set to none, If you don't
> find this
> object you want to do somehing. If you do find
> waldo and
> waldo has a phone you want to call waldo,
> otherwise you want
> to complain that he doesn't have a phone.
>
> Some people might code it like this:
>
> find-waldo: func [block [block!] /local found
> waldo no-fone?][
> found: false
> foreach obj block [
> if obj/name = "waldo" [
> waldo: obj
> found: true
> no-fone?: not none? obj/phone
> ]
> ]
> if not found [wheres-waldo?]
> either no-fone?
> [waldo-has-no-phone][call-waldo waldo/phone]
> ]
>
> That's a fair approach, similar to how you might
> tackle the
> problem in basic, maybe. But with REBOL you can
> get much
> more done in place. Most things return meaningful
> values so
> the left side of most functions represent an
> excellent
> place to dock another useful function, save space,
> save
> steps, and preserve the utility of results.
>
> How about this:
>
> find-waldo: func [block [block!] /local result][
> if not result: foreach obj block [
> if obj/name = "waldo" [break/return any
> [obj/phone yes]]
> ][wheres-waldo?]
> either issue? result [call-waldo
> result][waldo-has-no-phone]
> ]
>
> Okay, so we have less local variables, the code is
> smaller
> and therefore is more efficient usually (and in
> this case
> definitely). The first example trudged through the
> whole
> block before deciding the outcome, where above we
> BREAK/return as soon as we find waldo. The
> FOREACH will
> return the last evaluation, so if FOREACH makes it
> through
> the whole block with out ever finding waldo it
> will return a
> NONE from the last evalutation of the IF
> statement. We use
> the result of FOREACH to immediately determine if
> we found
> waldo. Now if result is not a NONE, it will be
> either an
> issue!, waldo's phone number (#222-111-3333), or a
> TRUE
> value (yes). The TRUE is arbitrary since we just
> have to
> return a non false / non none from BREAK/return
> and we only
> check if we have an issue which means it must be
> Waldo's
> phone number.
>
> Programmers will have different styles, but the
> language
> also has a style of its own.
>
> With REBOL it usually comes down to taking a
> function,
> writing it, then rewriting it a few more times,
> carving out
> the fat while expanding the capability. As a
> general rule
> most REBOL functions that are written can be
> reworked to
> accomplish more, to provide more use in the same
> amount of
> space or less. Code in the eye of the fly and
> seek to know
> the true path of the REBOL way! :-)
>
> -jeff
>
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=====
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