Z3 sources

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

lib/sat_model_converter.h

@@ -0,0 +1,81 @@
+/*++
+Copyright (c) 2011 Microsoft Corporation
+
+Module Name:
+
+    sat_model_converter.h
+
+Abstract:
+
+    Low level model converter for SAT solver.
+
+Author:
+
+    Leonardo de Moura (leonardo) 2011-05-26.
+
+Revision History:
+
+--*/
+#ifndef _SAT_MODEL_CONVERTER_H_
+#define _SAT_MODEL_CONVERTER_H_
+
+#include"sat_types.h"
+
+namespace sat {
+    /**
+       \brief Stores eliminated variables and Blocked clauses.
+       It uses these clauses to extend/patch the model produced for the
+       simplified CNF formula.
+       
+       This information may also be used to support incremental solving.
+       If new clauses are asserted into the SAT engine, then we can
+       restore the state by re-asserting all clauses in the model
+       converter.
+
+       This is a low-level model_converter. Given a mapping from bool_var to expr,
+       it can be converted into a general Z3 model_converter
+    */
+    class model_converter {
+    public:
+        enum kind { ELIM_VAR = 0, BLOCK_LIT };
+        class entry {
+            friend class model_converter;
+            unsigned           m_var:31;
+            unsigned           m_kind:1;
+            literal_vector     m_clauses; // the different clauses are separated by null_literal
+            entry(kind k, bool_var v):m_var(v), m_kind(k) {}
+        public:
+            entry(entry const & src):
+                m_var(src.m_var),
+                m_kind(src.m_kind),
+                m_clauses(src.m_clauses) {
+            }
+            bool_var var() const { return m_var; } 
+            kind get_kind() const { return static_cast<kind>(m_kind); }
+        };
+    private:
+        vector<entry>          m_entries;
+    public:
+        model_converter();
+        ~model_converter();
+        void operator()(model & m) const;
+
+        entry & mk(kind k, bool_var v);
+        void insert(entry & e, clause const & c);
+        void insert(entry & e, literal l1, literal l2);
+        void insert(entry & e, clause_wrapper const & c);
+
+        bool empty() const { return m_entries.empty(); }
+
+        void reset();
+        bool check_invariant(unsigned num_vars) const;
+        void display(std::ostream & out) const;
+        bool check_model(model const & m) const;
+
+        void copy(model_converter const & src);
+        void collect_vars(bool_var_set & s) const;
+    };
+    
+};
+
+#endif