Z3 sources

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

lib/smt_trail.h

@@ -0,0 +1,131 @@
+/*++
+Copyright (c) 2006 Microsoft Corporation
+
+Module Name:
+
+    smt_trail.h
+
+Abstract:
+
+    <abstract>
+
+Author:
+
+    Leonardo de Moura (leonardo) 2008-02-19.
+
+Revision History:
+
+--*/
+#ifndef _SMT_TRAIL_H_
+#define _SMT_TRAIL_H_
+
+namespace smt {
+
+    class context;
+
+    class trail {
+    public:
+        virtual ~trail() {
+        }
+        virtual void undo(context & ctx) = 0;
+    };
+    
+    template<typename T>
+    class value_trail : public trail {
+        T & m_value;
+        T   m_old_value;
+        
+    public:
+        value_trail(T & value):
+            m_value(value),
+            m_old_value(value) {
+        }
+        
+        virtual ~value_trail() {
+        }
+        
+        virtual void undo(context & ctx) {
+            m_value = m_old_value;
+        }
+    };
+
+    template<typename T>
+    class set_ptr_trail : public trail {
+        T * & m_ptr;
+    public:
+        set_ptr_trail(T * & ptr):
+            m_ptr(ptr) {
+            SASSERT(m_ptr == 0);
+        }
+        
+        virtual void undo(context & ctx) {
+            m_ptr = 0;
+        }
+    };
+    
+    template<typename T, bool CallDestructors=true>
+    class vector_value_trail : public trail {
+        vector<T, CallDestructors> & m_vector;
+        unsigned                     m_idx;
+        T                            m_old_value;
+    public:
+        vector_value_trail(vector<T, CallDestructors> & v, unsigned idx):
+            m_vector(v),
+            m_idx(idx),
+            m_old_value(v[idx]) {
+        }
+        
+        virtual ~vector_value_trail() {
+        }
+        
+        virtual void undo(context & ctx) {
+            m_vector[m_idx] = m_old_value;
+        }
+    };
+    
+    template<typename T, bool CallDestructors=true>
+    class push_back_trail : public trail {
+        vector<T, CallDestructors> & m_vector;
+    public:
+        push_back_trail(vector<T, CallDestructors> & v):
+            m_vector(v) {
+        }
+        
+        virtual void undo(context & ctx) {
+            m_vector.pop_back();
+        }
+    };
+    
+    class set_bitvector_trail : public trail {
+        svector<bool> & m_vector;
+        unsigned        m_idx;
+    public:
+        set_bitvector_trail(svector<bool> & v, unsigned idx):
+            m_vector(v),
+            m_idx(idx) {
+            SASSERT(m_vector[m_idx] == false);
+            m_vector[m_idx] = true;
+        }
+        
+        virtual void undo(context & ctx) {
+            m_vector[m_idx] = false;
+        }
+    };
+    
+    template<typename T>
+    class new_obj_trail : public trail {
+        T * m_obj;
+    public:
+        new_obj_trail(T * obj):
+            m_obj(obj) {
+        }
+        
+        virtual void undo(context & ctx) {
+            dealloc(m_obj);
+        }
+    };
+
+};
+
+#endif /* _SMT_TRAIL_H_ */
+