--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/elab_util.sml	Sat Jan 26 14:27:33 2008 -0500
@@ -0,0 +1,78 @@
+(* Copyright (c) 2008, Adam Chlipala
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * - Redistributions of source code must retain the above copyright notice,
+ *   this list of conditions and the following disclaimer.
+ * - Redistributions in binary form must reproduce the above copyright notice,
+ *   this list of conditions and the following disclaimer in the documentation
+ *   and/or other materials provided with the distribution.
+ * - The names of contributors may not be used to endorse or promote products
+ *   derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *)
+
+structure ElabUtil :> ELAB_UTIL = struct
+
+open Elab
+
+structure S = Search
+
+structure Kind = struct
+
+fun mapfold (f : (Elab.kind', 'state, 'abort) S.mapfold_arg) : (Elab.kind, 'state, 'abort) S.mapfolder =
+    let
+        fun mfk k acc =
+            S.bindP (mfk' k acc, f)
+
+        and mfk' (kAll as (k, loc)) =
+            case k of
+                KType => S.return2 kAll
+
+              | KArrow (k1, k2) =>
+                S.bind2 (mfk k1,
+                      fn k1' =>
+                         S.map2 (mfk k2,
+                              fn k2' =>
+                                 (KArrow (k1', k2'), loc)))
+
+              | KName => S.return2 kAll
+
+              | KRecord k =>
+                S.map2 (mfk k,
+                        fn k' =>
+                           (KRecord k', loc))
+
+              | KError => S.return2 kAll
+
+              | KUnif (_, ref (SOME k)) => mfk' k
+              | KUnif _ => S.return2 kAll
+    in
+        mfk
+    end
+
+fun exists f k =
+    case mapfold (fn (k, ()) =>
+                     if f k then
+                         S.Return ()
+                     else
+                         S.Continue (k, ())) k () of
+        S.Return _ => true
+      | S.Continue _ => false
+
+end
+
+end