From: Chad Perrin <perrin@...>
Date: 2007-09-17T03:22:52+09:00
Subject: Re: Newbie help

On Sun, Sep 16, 2007 at 11:27:35AM +0900, John Joyce wrote:
> On Sep 15, 2007, at 8:10 PM, Jeremy Woertink wrote:
> >>
> >Welcome to ruby. First to start the question about Symbols. Well, they
> >are used in hashes a lot, you could very well do { 'shape' => 'sock' }
> >and it works the same, but just to be consistent you use the object  
> >as a
> >symbol and it's value as what ever else. There is a lot more to that,
> >and i'm sure someone else will reply to tell you that.

As I understand it, there's generally less processing time involved in
resolving symbols than strings, but if you have a very long-running
program that performs some very similar actions involving symbols over
and over again you might end up consuming a lot of RAM because symbols
never really go away throughout the run of the program.  There may be a
way to get the interpreter to clear the hash table that stores symbols,
but I don't really know what it is off the top of my head.  If there's
such a thing, it probably involves scoping rules in Ruby, and maybe a
little luck.


> 
> To give further detail a block has two possible delimiter pairs { }  
> or do end
> As far as the interpreter is concerned they're same.

Again, if I recall correctly, that's not strictly true -- but the only
difference as far as I'm aware is precedence.  I seem to recall that
braces have a higher precedence than do...end.  This should only really
come into play when you are doing some fancy stuff on the line where the
do or open-brace appears, before the beginning of the block, I think.

Keep in mind I'm not Matz, Why, or the Pragmatic Programmer guys.  I'm
not what I'd call a Ruby "expert".  I may have inadvertently
misrepresented some feature of the language.  Despite a growing
preference for Ruby in most cases, I still have more experience with
Perl, and know that language better.  Take what I say with a grain of
"maybe he doesn't know what he's talking about" when I start talking
about the quirks and gotchas of working with Ruby.

-- 
CCD CopyWrite Chad Perrin [ http://ccd.apotheon.org ]
McCloctnick the Lucid: "The first rule of magic is simple. Don't waste your
time waving your hands and hopping when a rock or a club will do."