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changeset 2011:cfd604842006

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A .urs comment about [queryL*]
author Adam Chlipala <adam@chlipala.net>
date Sat, 03 May 2014 07:59:45 -0400
parents 403f0cc65b9c
children 2b2d07946e65
files lib/ur/top.urs
diffstat 1 files changed, 4 insertions(+), 0 deletions(-) [+]
line wrap: on
line diff
--- a/lib/ur/top.urs	Fri May 02 19:19:09 2014 -0400
+++ b/lib/ur/top.urs	Sat May 03 07:59:45 2014 -0400
@@ -155,6 +155,10 @@
             -> r ::: {K} -> folder r
             -> $(map tf1 r) -> $(map tf2 r) -> $(map tf3 r) -> xml ctx [] []
 
+(* Note that the next two functions return elements in the _reverse_ of the natural order!
+ * Such a choice interacts well with the time complexity of standard list operations.
+ * It's easy to regain the natural order by inverting a query's 'ORDER BY' condition. *)
+
 val queryL : tables ::: {{Type}} -> exps ::: {Type}
              -> [tables ~ exps] =>
                   sql_query [] [] tables exps