re-organization of muz

Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>

src/muz/base/dl_rule_transformer.h

@@ -0,0 +1,117 @@
+/*++
+Copyright (c) 2006 Microsoft Corporation
+
+Module Name:
+
+    dl_rule_transformer.h
+
+Abstract:
+
+    <abstract>
+
+Author:
+
+    Krystof Hoder (t-khoder) 2010-09-20.
+
+Revision History:
+
+--*/
+#ifndef _DL_RULE_TRANSFORMER_H_
+#define _DL_RULE_TRANSFORMER_H_
+
+#include"map.h"
+#include"vector.h"
+#include"dl_rule.h"
+#include"dl_rule_set.h"
+
+namespace datalog {
+
+    class context;
+
+    class rule_transformer {
+    public:
+        class plugin;
+    private:
+        friend class plugin;
+
+        typedef svector<plugin*> plugin_vector;
+        struct plugin_comparator;
+
+        context &        m_context;
+        rule_manager &   m_rule_manager;
+        bool             m_dirty;
+        svector<plugin*> m_plugins;
+        
+        void ensure_ordered();
+    public:
+
+        rule_transformer(context & ctx);
+        ~rule_transformer();
+
+        /**
+           \brief Reset all registered transformers.
+         */
+        void reset();
+
+        void cancel();
+        
+        /**
+           \brief Add a plugin for rule transformation.
+
+           The rule_transformer object takes ownership of the plugin object.
+        */
+        void register_plugin(plugin * p);
+
+        /**
+           \brief Transform the rule set using the registered transformation plugins. If the rule 
+           set has changed, return true; otherwise return false.
+        */
+        bool operator()(rule_set & rules);
+    };
+    
+    class rule_transformer::plugin {
+        friend class rule_transformer;
+
+        unsigned m_priority;
+        bool m_can_destratify_negation;
+        rule_transformer * m_transformer;
+
+        void attach(rule_transformer & transformer) { m_transformer = &transformer; }
+
+    protected:
+
+        /**
+           \brief Create a plugin object for rule_transformer.
+
+           The priority argument determines in what order will rules be applied to the rules
+           (higher priority plugins will be applied first).
+        */
+        plugin(unsigned priority, bool can_destratify_negation = false) : m_priority(priority), 
+            m_can_destratify_negation(can_destratify_negation), m_transformer(0) {}
+
+    public:
+        virtual ~plugin() {}
+
+        unsigned get_priority() { return m_priority; }
+        bool can_destratify_negation() const { return m_can_destratify_negation; }
+
+        virtual void cancel() {}
+
+        /**
+           \brief Return \c rule_set object with containing transformed rules or 0 if no
+           transformation was done.
+
+           The caller takes ownership of the returned \c rule_set object.
+        */
+        virtual rule_set * operator()(rule_set const & source) = 0;
+
+        /**
+           Removes duplicate tails.
+        */
+        static void remove_duplicate_tails(app_ref_vector& tail, svector<bool>& tail_neg);
+
+    };
+};
+
+#endif /* _DL_RULE_TRANSFORMER_H_ */
+