Another question about EQL. Again quoting from the CLHS dictionary
entry for EQL, it returns true
3. If they are both characters that represent the same character.
What does "same" mean here. (= (char-int c1) (char-int c2))? (I looked
up "same" in the glossary but it doesn't shed any light on this
situation as it says, "eql is the default predicate when none is
mentioned explicitly", which obviously doesn't help here.
-Peter
P.S. I'm asking all these picky questions because I'm trying to write
something that explains this and I want to make sure I get it
technically correct.
--
Peter Seibel ·····@javamonkey.com
The intellectual level needed for system design is in general
grossly underestimated. I am convinced more than ever that this
type of work is very difficult and that every effort to do it with
other than the best people is doomed to either failure or moderate
success at enormous expense. --Edsger Dijkstra
In article <··············@javamonkey.com>,
Peter Seibel <·····@javamonkey.com> wrote:
>Another question about EQL. Again quoting from the CLHS dictionary
>entry for EQL, it returns true
>
> 3. If they are both characters that represent the same character.
>
>What does "same" mean here.
That (char= c1 c2) => true.
--
Barry Margolin, ··············@level3.com
Genuity Managed Services, a Level(3) Company, Woburn, MA
*** DON'T SEND TECHNICAL QUESTIONS DIRECTLY TO ME, post them to newsgroups.
Please DON'T copy followups to me -- I'll assume it wasn't posted to the group.
Barry Margolin <··············@level3.com> writes:
> In article <··············@javamonkey.com>,
> Peter Seibel <·····@javamonkey.com> wrote:
> >Another question about EQL. Again quoting from the CLHS dictionary
> >entry for EQL, it returns true
> >
> > 3. If they are both characters that represent the same character.
> >
> >What does "same" mean here.
>
> That (char= c1 c2) => true.
Which also, implies:
(= (char-int c1) (char-int c2))
right?
-Peter
--
Peter Seibel ·····@javamonkey.com
The intellectual level needed for system design is in general
grossly underestimated. I am convinced more than ever that this
type of work is very difficult and that every effort to do it with
other than the best people is doomed to either failure or moderate
success at enormous expense. --Edsger Dijkstra
"Peter Seibel" <·····@javamonkey.com> wrote in message
···················@javamonkey.com...
> Barry Margolin <··············@level3.com> writes:
>
> > In article <··············@javamonkey.com>,
> > Peter Seibel <·····@javamonkey.com> wrote:
> > >Another question about EQL. Again quoting from the CLHS dictionary
> > >entry for EQL, it returns true
> > >
> > > 3. If they are both characters that represent the same character.
> > >
> > >What does "same" mean here.
> >
> > That (char= c1 c2) => true.
>
> Which also, implies:
>
> (= (char-int c1) (char-int c2))
>
> right?
>
What is char-int's contract in the face of multiple character sets?
"Scott McKay" <···@attbi.com> writes:
> "Peter Seibel" <·····@javamonkey.com> wrote in message
> ···················@javamonkey.com...
> > Barry Margolin <··············@level3.com> writes:
> > > That (char= c1 c2) => true.
> >
> > Which also, implies:
> >
> > (= (char-int c1) (char-int c2))
> >
> > right?
Yes.
> What is char-int's contract in the face of multiple character sets?
Good question. However, it's not an interesting question, because the
answer is "none". ANS 13.1.9 states that CHAR-INT produces a fixed
representation of the character, that is allowed to vary even between
images.
There aren't any character sets in CL as such. (External formats
allow interfaces to the external world to use the appropriate
character set.) A CL CHARACTER object represents a character, not an
encoding of a character. The Character chapter goes into some detail
about this, particularly ANS 13.1.2 "Introduction to Scripts and
Repertoires".
--
Pekka P. Pirinen
A definition tells you something about the way words are used,
not about the way the universe is put together.
- Simon van Dongen <sgvd(at)pi.net>