It is a special syntax for indexed queries, used for detect:[ifNone:] and
select: as you have suggested.

The ability to quickly access elements in an associative array is one of the
things that makes GemStone special, IMO. It also has some nice "fast" Set
operations (IdentitySet operations now, I guess) which lend themselves to
some interesting traversal patterns.

This is worthy of mention because of the large data volumes required to
implement sophisticated knowledge-based applications, such as the NL parser
that Dan proposed. I would love for Squeak to have these capabilities (along
with persistence, transactions and concurrency control).

There is a paper called "Making Smalltalk a Database System" (or something
like that) written by some of the original GemStone kernel engineers. I can
find the correct reference if anyone is interested and someone else doesn't
have it handy.

When you start to think of a database as a semantic network instead of a
bunch of data in tables (especially when you have Smalltalk as an engine),
it's really hard to go back.

Steve

> -----Original Message-----
> From: Benoit St-Jean [mailto:lamneth at aei.ca]
> Sent: July 18, 1999 12:55 PM
> To: squeak at cs.uiuc.edu
> Subject: re: Re: Status of braces.
>
>
> At 12:54 99-07-18 -0800, Alan Lovejoy wrote:
> >
> >> ** Original Sender: "Mike O'Brien" <obrien at rush.aero.org>
> >> Oops, nope, I'm wrong, it was the -> operator which was
> >> introduced to create Associations.
> >>
> >> 	I know I've seen {} used for something, but I'm darned
> >> if I can remember what.
> >>
> >> Mike O'Brien
> >
> >Hmmm... I seem to recall that Gemstone uses the "{}" delimiters
> >for something or other.  Was it some sort of special block,
> >perhaps?
>
> As I recall, they use the "{}" for iterating through records...
>
> e.g.
>
> aDatabaseOfMembers select: {:each | each programmingLanguage = 'Squeak'}
>
> Not sure about that one though!
> __________________________________________________________________
> __________
> Benoit St-Jean                           Creative Technologies
> International
> 871-8585 #234                           1440 Ste-Catherine ouest,
> Bureau 400
> email (work) : bstjean at creative.ca        Montreal, Quebec,
> Canada,  H3C 3R7
>       (home) : lamneth at aei.ca
>
> The opinions expressed in this message are my own personal views
> and do not
> reflect the official views of CTI
>