diff anagram/agcore/mrule.h @ 0:13d2b8934445

Import AnaGram (near-)release tree into Mercurial.
author David A. Holland
date Sat, 22 Dec 2007 17:52:45 -0500
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--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/anagram/agcore/mrule.h	Sat Dec 22 17:52:45 2007 -0500
@@ -0,0 +1,38 @@
+/*
+ * AnaGram, A System for Syntax Directed Programming
+ * Copyright 1993-2002 Parsifal Software. All Rights Reserved.
+ * See the file COPYING for license and usage terms.
+ *
+ * mrule.h - marked rules
+ */
+
+#ifndef MRULE_H
+#define MRULE_H
+
+#include "rule.h"
+
+class MarkedRule {
+public:
+  Rule rule;
+  int index;
+
+  MarkedRule() : rule(0), index(0) {}
+  MarkedRule(const Rule &r, int x) : rule(r), index(x) {}
+  MarkedRule(const Rule &r) : rule(r), index(r->length()) {}
+
+  int operator < (const MarkedRule &r) const {
+    if ((int) rule < (int) r.rule) return 1;
+    if ((int) r.rule < (int) rule) return 0;
+    return index < r.index;
+  }
+
+  Token leftToken()  { return rule.token(index - 1); }
+  Token rightToken() { return rule.token(index); }
+  int positionLeft()  { return index == 0; }
+  int positionRight() { return (unsigned) index == rule->length(); }
+  MarkedRule nextLeft()  { return MarkedRule(rule, index - 1); }
+  MarkedRule nextRight() { return MarkedRule(rule, index + 1); }
+};
+
+
+#endif /* MRULE_H */