# HG changeset patch
# User Ziv Scully <ziv@mit.edu>
# Date 1416879684 18000
# Node ID ff38b3e0cdfd27214b411b9bcc5f2c8a405fc0dd
# Parent  f7113855f3b74d1e0439f29ae5a92c82941df845
Add interface to UnionFind.

diff -r f7113855f3b7 -r ff38b3e0cdfd src/sqlcache.sml
--- a/src/sqlcache.sml	Tue Nov 11 04:25:20 2014 -0500
+++ b/src/sqlcache.sml	Mon Nov 24 20:41:24 2014 -0500
@@ -341,6 +341,7 @@
  fn Sql.Insert tableVals => valsToFormula tableVals
   | Sql.Delete (table, wher) => renameTables [(table, "T")] (sqexpToFormula wher)
   (* TODO: refine formula for the vals part, which could take into account the wher part. *)
+  (* TODO: use pushNegate instead of mapFormulaSigned? *)
   | Sql.Update (table, vals, wher) =>
     let
         val f = sqexpToFormula wher
diff -r f7113855f3b7 -r ff38b3e0cdfd src/union_find_fn.sml
--- a/src/union_find_fn.sml	Tue Nov 11 04:25:20 2014 -0500
+++ b/src/union_find_fn.sml	Mon Nov 24 20:41:24 2014 -0500
@@ -1,4 +1,10 @@
-functor UnionFindFn(K : ORD_KEY) = struct
+functor UnionFindFn(K : ORD_KEY) :> sig
+    type unionFind
+    val empty : unionFind
+    val union : unionFind * K.ord_key * K.ord_key -> unionFind
+    val union' : (K.ord_key * K.ord_key) * unionFind -> unionFind
+    val classes : unionFind -> K.ord_key list list
+end = struct
 
 structure M = BinaryMapFn(K)
 structure S = BinarySetFn(K)