Z3 sources

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>

lib/nat_set.h

@@ -0,0 +1,88 @@
+/*++
+Copyright (c) 2006 Microsoft Corporation
+
+Module Name:
+
+    nat_set.h
+
+Abstract:
+
+    Set of natural number with fast reset method.
+
+Author:
+
+    Leonardo de Moura (leonardo) 2007-03-27.
+
+Revision History:
+
+--*/
+#ifndef _NAT_SET_H_
+#define _NAT_SET_H_
+
+#include"vector.h"
+#include"limits.h"
+
+class nat_set {
+    unsigned          m_curr_timestamp;
+    svector<unsigned> m_timestamps;
+
+public:
+    nat_set(unsigned s = 0):
+        m_curr_timestamp(0),
+        m_timestamps() {
+        if (s > 0) {
+            m_timestamps.resize(s, 0);
+        }
+    }
+
+    // A nat_set is a function from [0..s-1] -> boolean.
+    // This method sets the domain of this function.
+    void set_domain(unsigned s) {
+        m_timestamps.resize(s, 0);
+    }
+
+    unsigned get_domain() const {
+        return m_timestamps.size();
+    }
+
+    // Assure that v is in the domain of the set.
+    void assure_domain(unsigned v) {
+        if (v >= get_domain()) {
+            set_domain(v+1);
+        }
+    }
+
+    bool contains(unsigned v) const {
+        return m_timestamps[v] > m_curr_timestamp;
+    }
+
+    void insert(unsigned v) {
+        m_timestamps[v] = m_curr_timestamp + 1;
+    }
+
+    void remove(unsigned v) {
+        m_timestamps[v] = m_curr_timestamp;
+    }
+
+    void reset() {
+        m_curr_timestamp++;
+        if (m_curr_timestamp == UINT_MAX) {
+            m_timestamps.fill(0);
+            m_curr_timestamp = 0;
+        }
+    }
+
+    bool empty() const {
+        svector<unsigned>::const_iterator it  = m_timestamps.begin();
+        svector<unsigned>::const_iterator end = m_timestamps.end();
+        for (; it != end; ++it) {
+            if (*it > m_curr_timestamp) {
+                return false;
+            }
+        }
+        return true;
+    }
+};
+
+#endif /* _NAT_SET_H_ */
+