Re: grouping elements

[Tony Graham <tgraham@xxxxxxxxxxxxxxxx>]

At 19 Feb 1999 11:23 +0100, Bas Peters wrote:
 > I have a stylesheet for database records that includes the following
 > rules:
 > 
 > (element MRCB100-c
 >    (make sequence
 >      (literal " ")
 >     (process-children)
 >   )
 > )
 > 
 > (element MRCB100-d
 >    (make sequence
 >      (literal " ")
 >     (process-children)
 >   )
 > )
 > 
 > (element MRCB100-e
 >    (make sequence
 >      (literal " ")
 >     (process-children)
 >   )
 > )
 > 
 > Is there a way to group the elements in one rule that repeates the
 > literal statement for all elements and not for one element?

The experimental DSSSL extensions in recent versions of Jade (requires
"-2" on the Jade command line) includes or-element construction rules:

(or-element (MRCB100-c MRCB100-d MRCB100-e)
  (sosofo-append
    (literal " ")
    (process-children)
  )
)

(Note that sososfo-append will give a flatter flow object tree than
nesting sequence flow objects, but the difference in processing time
may not even be noticable.)

Another option is to use a procedure:

(define (add-space #!optional (children (process-children)))
   (sosofo-append
      (literal " ")
      children)
   )
)

(element MRCB100-c
   (add-space)
)

Yet another option, especially if you have a lot of sibling elements
that all get the same treatment, is to process the elements in a
separate mode specified in the element construction rule of the parent
element of the siblings:

(element MRCB100
   (with-mode add-space (process-children)))

(mode add-space
   (default
      (add-space)))

It's tempting to try:

(element MRCB100
   (sosofo-append (node-list-map 'add-space (children (current-node)))))

but the procedure in node-list-map has to return a node-list, not a
sosofo.

Regards,


Tony Graham
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Tony Graham                            mailto:tgraham@xxxxxxxxxxxxxxxx
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