> I wrote a tutorial that talks, among other things, about a somewhat
> different approach to understanding blocks and procs:
>
> http://pine.fm/LearnToProgram/?Chapter=10
Chris, I can't see "yield" mentioned on that page. Is it just me, did I
overlook it? Is this intentionally?
Yep. On the next page (Chapter=11), I talk about, among other things,
yield. But I wanted to bring it in later as another way of doing it.
I mean, "yield" would be the first
thing that I'd describe on such a page; IMHO it's the default way to go when
passing blocks to methods (it's also the fastest AFAIK).
Default way to go for an experienced programmer to use? Or for a
non-programmer to learn? Very different situations.
I only use &block
if I have to store the block in a variable and / or have to pass it on to
another (recursive) method call.
Me, too... unless I'm teaching someone about it, because "yield" just
throws people off in my experience (not just my personal experience,
but my experience in teaching others).
If you look at the block as anonymous function it's clear that one needs a
special syntax to invoke it (can't use the name). That's exactly what
"yield" does.
Well, there's "anonymous" (like &block), and then there's *invisible*,
like what yield is calling. There's a big difference. I'm just
trying to make it visible, which is an important step on the way to
understandable.
Plus, passing a function around, and calling a function... these
things are extensions of what the reader has already learned at that
point. "yield" is something totally new. Better to describe this in
terms of something the reader is more familiar with first; then I can
just say "yield is a magical shortcut". Because it sort of it, right?
It's magical, and magical is (among other things) weird. That's my
hypothesis, anyway.
Yield: it's something you do to traffic with the right of way. It's
how many cookies your recipe is "supposed" to make if you don't eat
any of the dough. I can see the (imho, weak) analogy to
programming... but I think that describing what is going on in as
plain of terms as possible is the best way to teach this.
In any case, the PickAxe does it the other way, so hopefully we have
every learning style covered.
Chris