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diff lib/ur/basis.urs @ 2191:849404a3af27

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Change behavior of SQL equality to do the intuitive thing for nullable types
author Adam Chlipala <adam@chlipala.net>
date Sun, 01 Nov 2015 17:02:16 -0500
parents 14c45a0b6362
children
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--- a/lib/ur/basis.urs	Sun Nov 01 16:33:14 2015 -0500
+++ b/lib/ur/basis.urs	Sun Nov 01 17:02:16 2015 -0500
@@ -554,6 +554,9 @@
 val sql_mod : sql_binary int int int
 
 val sql_eq : t ::: Type -> sql_binary t t bool
+(* Note that the semantics of this operator on nullable types are different than for standard SQL!
+ * Instead, we do it the sane way, where [NULL = NULL]. *)
+
 val sql_ne : t ::: Type -> sql_binary t t bool
 val sql_lt : t ::: Type -> sql_binary t t bool
 val sql_le : t ::: Type -> sql_binary t t bool