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diff src/order.sml @ 479:ffa18975e661

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Broaden set of possible especializations
author Adam Chlipala <adamc@hcoop.net>
date Sat, 08 Nov 2008 14:42:52 -0500
parents 8a70e2919e86
children
line wrap: on
line diff
--- a/src/order.sml	Sat Nov 08 13:15:00 2008 -0500
+++ b/src/order.sml	Sat Nov 08 14:42:52 2008 -0500
@@ -42,4 +42,12 @@
         join (f (h1, h2), fn () => joinL f (t1, t2))
       | (_ :: _, nil) => GREATER
 
+fun joinO f (v1, v2) =
+    case (v1, v2) of
+        (NONE, NONE) => EQUAL
+      | (NONE, _) => LESS
+      | (_, NONE) => GREATER
+
+      | (SOME v1, SOME v2) => f (v1, v2)
+
 end