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[gacela.git] / src / gacela_misc.scm

diff --git a/src/gacela_misc.scm b/src/gacela_misc.scm
index b75a44eb1cf91a4d1c1158db9c754a5c06687b0a..d486b2650b734a2bea3ef7b977f42898ad7ef480 100644 (file)
--- a/src/gacela_misc.scm
+++ b/src/gacela_misc.scm
@@ -20,3 +20,7 @@
     (cond ((> (* p 2) n) p)
          (else (power (* p 2) n))))
   (power 1 n))
+
+(define-macro (pushnew elem list)
+  `(cond ((not (find (lambda (e) (eq? e ,elem)) ,list))
+         (set! ,list (cons ,elem ,list)))))