--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/search.sig	Sat Jan 26 14:27:33 2008 -0500
@@ -0,0 +1,62 @@
+(* 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.
+ *)
+
+signature SEARCH = sig
+
+    datatype ('state, 'abort) result =
+             Return of 'abort
+           | Continue of 'state
+
+    type ('data, 'state, 'abort) mapfold_arg =
+         'data * 'state -> ('data * 'state, 'abort) result
+
+    type ('data, 'state, 'abort) mapfolder =
+         'data -> 'state -> ('data * 'state, 'abort) result
+
+    val return2 : 'state1 -> 'state2 -> ('state1 * 'state2, 'abort) result
+
+    val map : ('state1, 'abort) result
+              * ('state1 -> 'state2)
+              -> ('state2, 'abort) result
+
+    val map2 : ('state2 -> ('state1 * 'state2, 'abort) result)
+               * ('state1 -> 'state1')
+               -> ('state2 -> ('state1' * 'state2, 'abort) result)
+                         
+    val bind : ('state1, 'abort) result
+               * ('state1 -> ('state2, 'abort) result)
+               -> ('state2, 'abort) result
+
+    val bind2 : ('state2 -> ('state1 * 'state2, 'abort) result)
+               * ('state1 -> 'state2 -> ('state1 * 'state2, 'abort) result)
+               -> ('state2 -> ('state1 * 'state2, 'abort) result)
+
+    val bindP : (('state11 * 'state12) * 'state2, 'abort) result
+                * ('state11 * 'state2 -> ('state11 * 'state2, 'abort) result)
+                -> (('state11 * 'state12) * 'state2, 'abort) result
+
+end