# HG changeset patch
# User Christian Urban <christian dot urban at kcl dot ac dot uk>
# Date 1471736312 -3600
# Node ID 5322e1c46890eb608df254bee95048ee9014b628
# Parent  4b454a6d1814fa193bf08747492564fe5436ffa8
added

diff -r 4b454a6d1814 -r 5322e1c46890 progs/rev.scala
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/progs/rev.scala	Sun Aug 21 00:38:32 2016 +0100
@@ -0,0 +1,8 @@
+def rev(r: Rexp) : Rexp = r match {
+  case ZERO => ZERO
+  case ONE => ONE
+  case CHAR(c) => CHAR(c)
+  case ALT(r1, r2) => ALT(rev(r1), rev(r2))
+  case SEQ(r1, r2) => SEQ(rev(r2), rev(r1))
+  case STAR(r) => STAR(rev(r))
+}