Matching the Unmatched Attributes

Sometimes it is useful to bind a list of attributes present in the element being matched, but which do not appear in the pattern. This is achieved by using a . rest) pattern at the end of the attribute list pattern. This is illustrated in the example below:

(sxml-match '(a (@ (z 1) (y 2) (x 3)) 4 5 6)
  [(a (@ (y ,www) . ,qqq) ,t ,u ,v)
   (list www qqq t u v)])

The above expression matches the attribute y and binds a list of the remaining attributes to the variable qqq. The result of the above expression is (2 ((z 1) (x 3)) 4 5 6).

This type of pattern also allows the binding of all attributes:

(sxml-match '(a (@ (z 1) (y 2) (x 3)))
  [(a (@ . ,qqq))
   qqq])

This document was generated on April 20, 2013 using texi2html 5.0.