Re: JESS: Who cares about chars?
Just my two cents: Returning int or char is far better than returning String. Object creation time is one of our big problems in Java. Right? SDG jco [EMAIL PROTECTED] wrote: > Well, Jess has its own LISP-like type system, following the one from > CLIPS. Jess has one type that Java doesn't (symbols) and doesn't make > many of the distinctions that Java does. For the most part this > doesn't matter; in a very high-level language, you're generally not > worrying about data types. Having the full range of Java data types in > a pattern-matching language would be a nightmare -- do two values not > match because they're not equal, or because one is an int and one is a > short? > > When Jess calls out to Java functions, though, it has to map the Java > types onto its own types and vice-versa, and that mapping has to be > predictable. In my code snippet below ( i.e., (call "foo" charAt 0) ) > that -is- the java.lang.String.charAt() function, and it -does- return > a char. The question is, given Jess's available types (INTEGER, LONG, > FLOAT, ATOM, STRING, EXTERNAL_ADDRESS) how should Jess represent that > char? What I'm suggesting is that INTEGER is a better match than > STRING, and I'm wondering if anybody has any code that would break if > I made this change. > > I think Bryan Talbot wrote: > > > > Why have it return an int instead of a char like the > > java.lang.String.charAt() method does? Also, with a method name like > > "charAt", I would intuitively expect a char type to be returned. > > > > >From: [EMAIL PROTECTED] > > > > > > > > >Currently, Jess maps Java char values onto Jess Strings; i.e., > > >the result of (call "foo" charAt 0) is "f". I'm starting to > > >think that this is the wrong mapping -- a Jess integer would > > >make more sense (i.e., 102.) Does anybody have an opinion, one > > >way or the other? > > > > > - > Ernest Friedman-Hill > Distributed Systems ResearchPhone: (925) 294-2154 > Sandia National LabsFAX: (925) 294-2234 > Org. 8920, MS 9012 [EMAIL PROTECTED] > PO Box 969 http://herzberg.ca.sandia.gov > Livermore, CA 94550 > > > To unsubscribe, send the words 'unsubscribe jess-users [EMAIL PROTECTED]' > in the BODY of a message to [EMAIL PROTECTED], NOT to the list > (use your own address!) List problems? Notify [EMAIL PROTECTED] > To unsubscribe, send the words 'unsubscribe jess-users [EMAIL PROTECTED]' in the BODY of a message to [EMAIL PROTECTED], NOT to the list (use your own address!) List problems? Notify [EMAIL PROTECTED]
Re: JESS: Who cares about chars?
Well, Jess has its own LISP-like type system, following the one from CLIPS. Jess has one type that Java doesn't (symbols) and doesn't make many of the distinctions that Java does. For the most part this doesn't matter; in a very high-level language, you're generally not worrying about data types. Having the full range of Java data types in a pattern-matching language would be a nightmare -- do two values not match because they're not equal, or because one is an int and one is a short? When Jess calls out to Java functions, though, it has to map the Java types onto its own types and vice-versa, and that mapping has to be predictable. In my code snippet below ( i.e., (call "foo" charAt 0) ) that -is- the java.lang.String.charAt() function, and it -does- return a char. The question is, given Jess's available types (INTEGER, LONG, FLOAT, ATOM, STRING, EXTERNAL_ADDRESS) how should Jess represent that char? What I'm suggesting is that INTEGER is a better match than STRING, and I'm wondering if anybody has any code that would break if I made this change. I think Bryan Talbot wrote: > > Why have it return an int instead of a char like the > java.lang.String.charAt() method does? Also, with a method name like > "charAt", I would intuitively expect a char type to be returned. > > >From: [EMAIL PROTECTED] > > > > > >Currently, Jess maps Java char values onto Jess Strings; i.e., > >the result of (call "foo" charAt 0) is "f". I'm starting to > >think that this is the wrong mapping -- a Jess integer would > >make more sense (i.e., 102.) Does anybody have an opinion, one > >way or the other? > > - Ernest Friedman-Hill Distributed Systems ResearchPhone: (925) 294-2154 Sandia National LabsFAX: (925) 294-2234 Org. 8920, MS 9012 [EMAIL PROTECTED] PO Box 969 http://herzberg.ca.sandia.gov Livermore, CA 94550 To unsubscribe, send the words 'unsubscribe jess-users [EMAIL PROTECTED]' in the BODY of a message to [EMAIL PROTECTED], NOT to the list (use your own address!) List problems? Notify [EMAIL PROTECTED]
RE: JESS: Who cares about chars?
Title: RE: JESS: Who cares about chars? -BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Why have it return an int instead of a char like the java.lang.String.charAt() method does? Also, with a method name like "charAt", I would intuitively expect a char type to be returned. - -Bryan >-Original Message- >From: [EMAIL PROTECTED] >[mailto:[EMAIL PROTECTED]] >Sent: Friday, January 04, 2002 4:07 AM >To: Jess Mailing List >Subject: JESS: Who cares about chars? > > > >Currently, Jess maps Java char values onto Jess Strings; i.e., >the result of (call "foo" charAt 0) is "f". I'm starting to >think that this is the wrong mapping -- a Jess integer would >make more sense (i.e., 102.) Does anybody have an opinion, one >way or the other? > >- >Ernest Friedman-Hill >Distributed Systems Research Phone: (925) 294-2154 >Sandia National Labs FAX: (925) 294-2234 >Org. 8920, MS 9012 [EMAIL PROTECTED] >PO Box 969 http://herzberg.ca.sandia.gov >Livermore, CA 94550 > > >To unsubscribe, send the words 'unsubscribe jess-users >[EMAIL PROTECTED]' in the BODY of a message to >[EMAIL PROTECTED], NOT to the list (use your own address!) >List problems? Notify [EMAIL PROTECTED] > > -BEGIN PGP SIGNATURE- Version: PGP Personal Privacy 6.5.2 iQA/AwUBPDYU0kzuKKcxAa+OEQJ8NACgsjAOO+SdIS05Wsqk1Q0j1WV81yoAniYF oGaGH0XxpK1aT+XpqUmOdMaD =tKQI -END PGP SIGNATURE-
JESS: Who cares about chars?
Currently, Jess maps Java char values onto Jess Strings; i.e., the result of (call "foo" charAt 0) is "f". I'm starting to think that this is the wrong mapping -- a Jess integer would make more sense (i.e., 102.) Does anybody have an opinion, one way or the other? - Ernest Friedman-Hill Distributed Systems ResearchPhone: (925) 294-2154 Sandia National LabsFAX: (925) 294-2234 Org. 8920, MS 9012 [EMAIL PROTECTED] PO Box 969 http://herzberg.ca.sandia.gov Livermore, CA 94550 To unsubscribe, send the words 'unsubscribe jess-users [EMAIL PROTECTED]' in the BODY of a message to [EMAIL PROTECTED], NOT to the list (use your own address!) List problems? Notify [EMAIL PROTECTED]
