Z3 sources

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

lib/dl_mk_unbound_compressor.h

@@ -0,0 +1,91 @@
+/*++
+Copyright (c) 2006 Microsoft Corporation
+
+Module Name:
+
+    dl_mk_unbound_compressor.h
+
+Abstract:
+
+    <abstract>
+
+Author:
+
+    Krystof Hoder (t-khoder) 2010-10-4.
+
+Revision History:
+
+--*/
+#ifndef _DL_MK_UNBOUND_COMPRESSOR_H_
+#define _DL_MK_UNBOUND_COMPRESSOR_H_
+
+#include<utility>
+
+#include"map.h"
+#include"obj_pair_hashtable.h"
+
+#include"dl_context.h"
+#include"dl_rule_set.h"
+#include"dl_rule_transformer.h"
+
+namespace datalog {
+
+    /**
+       \brief Functor for introducing auxiliary predicates to avoid unbound variables in
+       rule heads.
+
+       A rule
+       P(x,_) :- T(x).
+       is replaced by 
+       P1(x) :- T(x).
+       and for each occurrence of P in a tail of a rule, a new rule is added with P1 in 
+       its place.
+    */
+    class mk_unbound_compressor : public rule_transformer::plugin {
+        /** predicate and index of compressed argument */
+        typedef std::pair<func_decl*,unsigned> c_info;
+        typedef pair_hash<ptr_hash<func_decl>,unsigned_hash> c_info_hash;
+        /** predicates that are results of compression */
+        typedef map<c_info, func_decl*, c_info_hash, default_eq<c_info> > c_map;
+        typedef hashtable<c_info, c_info_hash, default_eq<c_info> > in_progress_table;
+        typedef svector<c_info> todo_stack;
+
+        context &			m_context;
+        ast_manager &       m_manager;
+        rule_ref_vector     m_rules;
+        bool                m_modified;
+        todo_stack          m_todo;
+        in_progress_table   m_in_progress;
+        c_map               m_map;
+
+        /**
+        Relations that contain facts
+        */
+        decl_set            m_non_empty_rels;
+
+        ast_counter         m_head_occurrence_ctr;
+
+        ast_ref_vector      m_pinned;
+
+
+        bool is_unbound_argument(rule * r, unsigned head_index);
+        bool has_unbound_head_var(rule * r);
+
+        void detect_tasks(unsigned rule_index);
+        void add_task(func_decl * pred, unsigned arg_index);
+        void try_compress(unsigned rule_index);
+        void add_decompression_rules(unsigned rule_index);
+        void mk_decompression_rule(rule * r, unsigned tail_index, unsigned arg_index, rule_ref& res);
+        void add_decompression_rule(rule * r, unsigned tail_index, unsigned arg_index);
+        void replace_by_decompression_rule(unsigned rule_index, unsigned tail_index, unsigned arg_index);
+        void reset();
+    public:
+        mk_unbound_compressor(context & ctx);
+        
+        rule_set * operator()(rule_set const & source, model_converter_ref& mc, proof_converter_ref& pc);
+    };
+
+};
+
+#endif /* _DL_MK_UNBOUND_COMPRESSOR_H_ */
+