This is a plug-in for Qi-YACC that gives segment pattern-matching. <<...>> is a stuff matcher. 

(defcc <grab-numbers> 
       <<X>> <numbers> <<Y>> := <numbers>;) 


(defcc <numbers> 
       <number> <numbers>; 
       <number>;) 


(defcc <number> 
        -*- := (if (number? -*-) [-*-] #\Escape);) 


(defcc <grab-my-name> 
   <<X>> :name <<Y>> := <<Y>>;) 


Examples: 


(compile <grab-my-name> [ghhghg 7 8 :name Mark Tarver]) 
[Mark Tarver] 


(compile <grab-numbers> [just some numbers 1 2 3/4 tum te tum]) 
[1 2 3/4]