2011/7/13 Marco Maggi <marco.maggi-i...@poste.it>: > Panicz Maciej Godek wrote: > >> I've been wondering if there is a way to represent this >> sort of pattern for the pattern matcher provided by Wright >> (and Guile). > > The syntax should be something like: > > (match '(Mr Hulot and I need a vacation) > ((?x ... 'need ?y ...) > (write (list ?x ?y)) > (newline))) > > but at present multiple ellipses are not supported at the > same level (that is in the same list or the same vector). > It is possible to do it, but a policy (greedy/non-greedy) > must be adopted to solve ambiguous cases and it gets > complicated.
I agree that it could get complicated for the ambiguous cases, but it should at least be possible for the simple ones. I think that the lack of this capability is a serious limitation of a pattern matcher. I'm not well acquainted with regular expressions, but I could try to resolve this issue upon the book that I'm currently reading -- provided that there's no one dealing with it at the moment Regards M.