Re: defclass and defconcept

Thanks Thomas,

I was a little confused by the fact that some classes are subsets of others. 
For example, the following query indicates that some stella classes appear 
to be related via powerloom's subset-of relation:

PL-KERNEL-KB |= (retrieve all (subset-of ?x number))

There are 3 solutions:
  #1: ?X=NUMBER
  #2: ?X=INTEGER
  #3: ?X=FLOAT

Also, the following query suggests that the interval-integer class is 
related to powerloom's thing and scalar-interval concepts via the subset-of 
relation:

PL-KERNEL-KB |= (retrieve all (subset-of integer-interval ?x))

There are 4 solutions:
  #1: ?X=INTEGER-INTERVAL
  #2: ?X=THING
  #3: ?X=SCALAR-INTERVAL
  #4: ?X=SCALAR

I suppose there is a measure of inter-mingling of stella classes and 
powerloom concepts, relations etc.

Once again, thanks for the info,
Cameron.

----- Original Message ----- 
From: "Thomas Russ" <[email protected]>
To: "Cameron Ross" <[email protected]>
Cc: "PowerLoom Forum" <[email protected]>
Sent: Wednesday, August 22, 2007 12:22 PM
Subject: Re: [PowerLoom Forum] defclass and defconcept


>
> On Aug 20, 2007, at 8:54 PM, Cameron Ross wrote:
>
>> What is the difference between defclass and defconcept?
>
> DEFCLASS is used to define Stella classes, in other words,  programming 
> language level classes.
>
> DEFCONCEPT is used to define PowerLoom concepts, a particular kind of 
> unary relation.
>
> You would only use DEFCLASS if you want to do Stella programming.   For 
> PowerLoom, you need to use DEFCONCEPT.
>
>
>>   Also, what is NON-OBJECT?
>
> From the documentation string associated with it:
>
>   "A data structure that cannot be a dispatch argument to
>    a (real) method, because its type is not accessible at run-time."
>
> This is used by the Stella code translator to identify types that do  not 
> have a realization in the native object system, and thus cannot  have 
> proper method dispatch work for it.  Some examples are literals  like 
> INTEGER, which are not legal dispatch types in Java (int) or C++  (int) or 
> even Common Lisp (FIXNUM).  So they need to be handled  specially by the 
> translator.  Currently the only non-objects in  Stella are all programming 
> language literals such as numbers, boolean  values and strings.
>