Re: Guile and GNU TeXmacs

[Joris van der Hoeven]

On Thu, 13 Dec 2001, Thomas Wawrzinek wrote:

> e0: set outgrammar tex;
> 
> However, this suffers from the same bug as standard grammar-
> 
> I have patched my version of JACAL with the append patch.
> 
> This seems like a real bug in JACAL to me. Also, I'm not sure this does what
> was originally intended (see the comment in the patch).
> 
> --- unparse.scm.old     Thu Dec 13 11:31:52 2001
> +++ unparse.scm Thu Dec 13 11:05:26 2001
> @@ -156,6 +156,15 @@
>          (display-line (car line)
>                        (cadr line)
>                        (cddr line)))
> +       ((symbol? (cadr line))
> +        (display (make-string (- (car line) hpos) fillchr))
> +        ;; Hmm! I don't know whether this is exactly what is intended.
> +        ;; See remark for symbol 'BREAK at beginning of this file ...
> +        ;;(if (eq? (cadr line) 'BREAK)
> +        ;;    (newline))
> +         (display-line (car line) 
> +                       fillchr
> +                       (cddr line)))
>         (else
>          (slib:error 'display-line line))))

Thanks for the patch, which improves the output.
Unfortunately, the output remains buggy.
For instance, you may try to enter the first expressions
from the first example of a jacal session:

e2: a:[[1, 3, 5], [2, 4, 7]];

...

e3: b:[2, 4];

...

e4: a + b;

Jacal breaks...

Other bug: try to expand (a+b)^50. Not only Jacal is extremely
slow on this example, but the output is hyphenated incorrectly.

> And for TeX output, it still seem's to be semantically wrong :-(

That is also a problem. We usually need  a very good algorithm
for TeX/LaTeX output, preferrably with an option in order to enhance
the semantics (for instance, we recommend the multiplication to
be output as '\*' instead of ' ' when interfacing with TeXmacs;
this helps us to copy and paste expressions to other
computer algebra systems).

In fact, in would be nice to have some Scheme tools inside TeXmacs
for parsing mathematical expressions, for rewriting them,
and for displaying them (either as TeX/LaTeX or directly as
TeXmacs expressions). If someone is interested...

> BTW: http://www.math.u-psud.fr/~vdhoeven: Is this link broken?

Not that I noticed, but the page is quite out of date;
when I will have time, I intend to completely redesign it.

Regards,

-Joris-

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Joris van der Hoeven <address@hidden>
http://www.texmacs.org: GNU TeXmacs scientific text editor
http://www.math.u-psud.fr/~vdhoeven: personal homepage
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