add priority queue to instantiation

src/sat/smt/q_queue.h

@@ -0,0 +1,87 @@
+/*++
+Copyright (c) 2020 Microsoft Corporation
+
+Module Name:
+
+    q_queue.h
+
+Abstract:
+
+    Instantiation queue for quantifiers
+
+Author:
+
+    Nikolaj Bjorner (nbjorner) 2021-01-24
+
+--*/
+#pragma once
+
+#include "ast/quantifier_stat.h"
+#include "ast/cost_evaluator.h"
+#include "ast/rewriter/cached_var_subst.h"
+#include "parsers/util/cost_parser.h"
+#include "sat/smt/q_fingerprint.h"
+
+
+
+namespace euf {
+    class solver;
+};
+
+namespace q {
+
+    class ematch;
+
+    class queue {
+
+        struct stats {
+            unsigned m_num_instances, m_num_lazy_instances;
+            void reset() { memset(this, 0, sizeof(*this)); }
+            stats() { reset(); }
+        };
+
+        ematch&                       em;
+        euf::solver&                  ctx;
+        ast_manager &                 m;
+        qi_params const &             m_params;
+        stats                         m_stats;
+        expr_ref                      m_cost_function;
+        expr_ref                      m_new_gen_function;
+        cost_parser                   m_parser;
+        cost_evaluator                m_evaluator;
+        cached_var_subst              m_subst;
+        svector<float>                m_vals;
+        double                        m_eager_cost_threshold { 0 };
+        struct entry {
+            fingerprint * m_qb;
+            float         m_cost;
+            bool          m_instantiated{ false };
+            entry(fingerprint * f, float c):m_qb(f), m_cost(c) {}
+        };
+        struct reset_new_entries;
+        struct reset_instantiated;
+
+        svector<entry>                m_new_entries;
+        svector<entry>                m_delayed_entries;
+
+        float get_cost(fingerprint& f);
+        void set_values(fingerprint& f, float cost);
+        void init_parser_vars();
+        void setup();
+        unsigned get_new_gen(fingerprint& f, float cost);
+        void instantiate(entry& e);
+
+    public:
+
+        queue(ematch& em, euf::solver& ctx);
+            
+        void insert(fingerprint* f);
+
+        bool propagate();
+
+        bool lazy_propagate();
+
+        void collect_statistics(::statistics & st) const;
+
+    };
+}