Re: breaking a string at record ends

[Brandon Ibach <bibach@xxxxxxxxxxxxxx>]

Quoting Jany Quintard <quintard.j@xxxxxx>:
> So I process the contents of xmp with a function :
> (define (output-xmp liste)
>   (let loop ((chars liste)
>              (result (empty-sosofo)))
>   (if (null? chars)
>       result
>       (loop (cdr chars)
>             (sosofo-append 
>               result
>               (if (char-property 'record-end? (car chars))
>                   (make empty-element gi: "br")
>                   (literal (string (car chars)))))))))
> 
> This works, but I am none too proud of it. 
> The "(literal (string (car chars)))" seems *very* complicated 
> and I wonder if there is not a better way to do it (using (make character)
> maybe ?).
> 
   Well, yes, you should be able to replace the (literal ...) with
(make character char: (car chars)).  Or, you could take a different
approach to the whole function and just have it return a modified
node-list.  So, instead of:
     (element XMP (output-xmp (string->list (data (current-node)))))
you'd have:
     (element XMP (process-node-list (filter-xmp (children (current-node)))))

     (define (filter-xmp liste)
       (let ((br (node-list-first (select-elements
                     (descendants (current-root)) "BR"))))
         (let loop ((chars liste)
                    (result (empty-sosofo)))
           (if (node-list-empty? chars)
               result
               (loop (node-list-rest chars)
                     (node-list
                       result
                       (let ((c (node-list-first chars)))
                         (if (char-property 'record-end? c) br c))))))))

   Of course, this assumes that you've got a <br> element somewhere in
your source document that we can copy into our output node-list,
because DSSSL provides no way to "construct" such a node.  If this is
not the case, this function will break.  You could do something as
elaborate as parsing an extra document which has a <br> in it (and,
perhaps, little more), if needed, but that would tend to defeat the
simplicity gained by this approach.

-Brandon :)


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