Reorganizing the code

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

src/sat/sat_clause_use_list.cpp

@@ -0,0 +1,57 @@
+/*++
+Copyright (c) 2011 Microsoft Corporation
+
+Module Name:
+
+    sat_clause_use_list.cpp
+
+Abstract:
+
+    Clause use list
+
+Author:
+
+    Leonardo de Moura (leonardo) 2011-05-31.
+
+Revision History:
+
+--*/
+#include"sat_clause.h"
+#include"sat_clause_use_list.h"
+
+namespace sat {
+
+    bool clause_use_list::check_invariant() const {
+#ifdef LAZY_USE_LIST
+        unsigned sz = 0;
+        for (unsigned i = 0; i < m_clauses.size(); i++) 
+            if (!m_clauses[i]->was_removed())
+                sz++;
+        SASSERT(sz == m_size);
+#endif
+        return true;
+    }
+
+#ifdef LAZY_USE_LIST
+    void clause_use_list::iterator::consume() {
+        while (true) {
+            if (m_i == m_size)
+                return;
+            if (!m_clauses[m_i]->was_removed()) {
+                m_clauses[m_j] = m_clauses[m_i];
+                return;
+            }
+            m_i++;
+        }
+    }
+#endif
+
+    clause_use_list::iterator::~iterator() {
+#ifdef LAZY_USE_LIST
+        while (m_i < m_size)
+            next();
+        m_clauses.shrink(m_j);
+#endif
+    }
+
+};