--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/anagram/agcore/checksum.h	Sat Dec 22 17:52:45 2007 -0500
@@ -0,0 +1,44 @@
+/*
+ * AnaGram, A System for Syntax Directed Programming
+ * Copyright 1993-1999 Parsifal Software. All Rights Reserved.
+ * Copyright 2006 David A. Holland. All Rights Reserved.
+ * See the file COPYING for license and usage terms.
+ *
+ * checksum.h - self-checksum module
+ */
+
+#ifndef CHECKSUM_H
+#define CHECKSUM_H
+
+enum summable {
+  SUM_AG1,
+  SUM_AG,
+  SUM_AGCL,
+};
+
+struct suminfo {
+  unsigned long length;
+  unsigned long sum;
+};
+
+struct sumentry {
+  summable what;
+  unsigned long offset;
+  suminfo correct;
+  suminfo observed;
+};
+
+void observeSum(sumentry *s);
+
+void sum_remember_argv0(const char *argv0);
+
+inline int operator != (const suminfo &a, const suminfo &b) {
+  return a.length != b.length || a.sum != b.sum;
+}
+
+// apparently required to have an AgStack<sumentry> (sigh)
+inline int operator < (const sumentry &, const sumentry &) {
+  return 0;
+}
+
+#endif /* CHECKSUM_H */