#1 testing against eof-object value believed non-portable

[Jörg Höhle]

Hi,

I believe there's a portability bug in SSAX.scm testing part:
(run-test (letrec
((a-tag (make-xml-token 'START (string->symbol "BR")))
(a-ref (make-xml-token 'ENTITY-REF (string->symbol "lt")))
(eof-object (with-input-from-string "" read))
...

1. I've a little problem because I haven't with-input-from-string in Kawa, but that's not the point
here.

2. R5RS provides an eof-object? predicate, not a eof-object constant, and says "The precise set of
end of objects will vary among implementations, [...]".
I.e. I believe code to be in error which invokes
(equal? token expected-token)) ; where expect-token is the above eof-object
because it may not work in the presence of multiple EOF objects.
[This is not a problem in Kawa which has a unique such object: #!eof]

I believe this fraction of the testing code ought to be rewritten in a way to use the R5RS
eof-object? predicate instead of the above test:

(if this-is-an-eof-test (eof-object? token) (equal? token expected-token))

Regards,
Jörg Höhle.

[Jörg Höhle]

patch to above and other small bugs

[Jörg Höhle]

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I made the above sketched patches and other tiny fixes which
I submit as an annotated diff/patch file against the CVS
snapshot that I downloaded.
Please include in CVS. I transfer copyright to Oleg Kiselyov
and put it into the public domain.

[Oleg Kiselyov]

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According to an interpretation kindly provided by an R5RS
author, R5RS systems are meant to have only one EOF object
(which may vary from one system to another).
See a message "Re: testing against eof-object value believed
non-portable SSAX code" posted on July 14, 2003 on the
SSAX-SXML mailing list for more details.

[Jörg Höhle]

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Well, even if you don't feel a need for that part of the
patch (but see my response from 30th of July), there's more
than that in the attached patch file and you should really
look at it and take note of what I put there.

Regards,
Jrg Hhle.

[Oleg Kiselyov]

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Applied suggested changes to SSAX.scm. For more details,
see a message posted on the SSAX-SXML list on
Aug 1, 2003.