[MUD-Dev] TECH: programming languages (was: Re: TECH: STL / Heaps, etc.)

[Jon Lambert]

Ola Fosheim Grøstad wrote:
> Jon Lambert wrote:

>> SQL is a 4th generation programming language and is
>> algorithmically non-predictive by design.

> 4th generation... blah... All SQL provided was syntactical sugar
> and a lack of expressiveness... It is better described as a query
> language IMO, designed to be so close to English that your CEO can
> use it.

> Shouldn't 4th generation actually have domain knowledge?

Opinions on 4GL means are widespread.  The first time I encountered
the term was one of James Martin's books.  If I'm not mistaken he
originally coined the term.  In that book he defined 4GLs as
"non-procedural" languages.  He wrote a another book later just on
4GLs during the 4GL craze.  In that one he changed the definition to
"any tool capable of performing a development task in one tenth of
the time necessary to perform that task using a 3GL".  Quite a
general definition.  In both cases SQL fit his definitions.

  Nijssen, wrote a more specific definition:

    1) primarily declarative
    2) highly interactive
    3) relationally complete
    4) should employ associative addressing
    5) should include support for
       a) dynamic optimisation
       b) data security
       c) a data dictionary
       d) automatic recovery
       e) a relational screen interface

He also claimed SQL was a 4GL, despite ANSI SQL standard not having
5-e above.  ISQL(DBQ) which Nijssen developed does have all the
features.

>> The speed of RDMSs has nothing to do with the original issue of a
>> high level languages determining an optimal approach to solving a
>> problem.  I think the example is an excellent one.  You are
>> perhaps taking the example literally though.  Don't assume there
>> is an RDBMS at all.  SQL can just as easily interface to a file
>> system, as well as an in-memory structures of some sort.

> Can you easily deal with hierarchical/recursive structures in SQL?

Of course.

> I thought SQL was pretty much tied to fixed tables.

Dealing with the above is done with normalization, joins, foreign
keys, etc.  For example, IDMS and IMS are best defined as
network/hierarchical databases.  But most anything done in them can
also be done in a relational database, just differently.

>> Besides, IIRC, haven't you argued in the past _for_ a mud design
>> that supported non-predictive, open and undefined user actions!!!

> So what? I haven't claimed that you can't do a MUD using a
> relational database. (and I don't think I've explicitly called for
> undefined user actions, I am in favour of a small and powerful set
> of user actions)

>> It's obvious, at least to me, that such a beast, if ever written,
>> would have to sport a smart high-level or abstract "language" of
>> some sort.

> I don't think it has to, (the physical world does not), but I
> think it is a good idea to have an optimizing search/unification
> engine "down there".

I'm not sure exactly what you mean here by the physical world not
having abstract interfaces or languages.  I mean in communicating
with another individual we use a number of abstract interfaces like
language and gestures being rather popular these days.  In deciding
to "pick up that rock over there" our brain uses some sort of
pre-visualization planning technique (possibly an abstract language
in itself) which is somehow optimized into a series of interruptible
(scratch that itch on the way to the rock, or dodge that mountain
lion hiding behind it) low level mechanical instructions.

Pre-visualization may be one key why some text interfaces have a
better "initial" feel to more people than others do.  Without a
doubt with repeated usage we relearn and reprogram ourselves so an
interface's abstract symbolics feel "natural" even when they're not.
(i.e. PIP file, CP file, COPY file).  I don't know about you but the
split second before I've started typing "MV file dest" I know I've
literally seen it take place in my "mind's eye".  Anyways what do I
know?  I'm not a biologist or a psychologist, although I have had
experience and access to the same equipment they've been using for
quite a long time. :-P

--
--* Jon A. Lambert - TychoMUD        Email:jlsysinc at ix.netcom.com *--
--* Mud Server Developer's Page <http://tychomud.home.netcom.com> *--
--* If I had known it was harmless, I would have killed it myself.*--


_______________________________________________
MUD-Dev mailing list
MUD-Dev at kanga.nu
https://www.kanga.nu/lists/listinfo/mud-dev