printing

6 years ago · 126538d868
parent bfbd91664a
commit 126538d868
1 changed files with 3 additions and 1 deletions
--- a/quad/quad/quad.rkt
+++ b/quad/quad/quad.rkt
@ -62,7 +62,9 @@
                           (string-join (map ~v (flatten (hash->list (quad-attrs q))))
                                    " " #:before-first "(" #:after-last ")")
                           "")
-                       (string-join (map ~v (quad-elems q)) " " #:before-first " ")) p))
+                       (match (quad-elems q)
+                         [(? pair?) (string-join (map ~v (quad-elems q)) " " #:before-first " ")]
+                         [_ ""])) p))
  #:methods gen:equal+hash
  [(define equal-proc quad=?)
   (define (hash-proc h recur) (equal-hash-code h))