refactor(library/blast): use branch_extension for recursor_action

src/library/blast/hypothesis.h

@@ -22,6 +22,13 @@ typedef buffer<unsigned>                hypothesis_idx_buffer;
 template<typename T>
 using hypothesis_idx_map = typename lean::rb_map<unsigned, T, unsigned_cmp>;
 
+/* trick to make sure the rb_map::erase_min removes the hypothesis with biggest weight */
+struct inv_double_cmp {
+    int operator()(double const & d1, double const & d2) const { return d1 > d2 ? -1 : (d1 < d2 ? 1 : 0); }
+};
+
+typedef rb_map<double, hypothesis_idx, inv_double_cmp>   hypothesis_priority_queue;
+
 class hypothesis {
     friend class state;
     name               m_name;         // for pretty printing

src/library/blast/init_module.cpp

@@ -10,6 +10,7 @@ Author: Leonardo de Moura
 #include "library/blast/blast_tactic.h"
 #include "library/blast/simplifier.h"
 #include "library/blast/options.h"
+#include "library/blast/recursor_action.h"
 
 namespace lean {
 void initialize_blast_module() {
@@ -19,8 +20,10 @@ void initialize_blast_module() {
     initialize_blast();
     blast::initialize_simplifier();
     initialize_blast_tactic();
+    blast::initialize_recursor_action();
 }
 void finalize_blast_module() {
+    blast::finalize_recursor_action();
     finalize_blast_tactic();
     blast::finalize_simplifier();
     finalize_blast();

src/library/blast/recursor_action.cpp

@@ -13,6 +13,28 @@ Author: Leonardo de Moura
 
 namespace lean {
 namespace blast {
+static unsigned g_ext_id = 0;
+struct recursor_branch_extension : public branch_extension {
+    hypothesis_priority_queue m_rec_queue;
+    recursor_branch_extension() {}
+    recursor_branch_extension(recursor_branch_extension const & b):m_rec_queue(b.m_rec_queue) {}
+    virtual ~recursor_branch_extension() {}
+    virtual branch_extension * clone() { return new recursor_branch_extension(*this); }
+    virtual void hypothesis_activated(hypothesis const &, hypothesis_idx) {}
+    virtual void hypothesis_deleted(hypothesis const &, hypothesis_idx) {}
+};
+
+void initialize_recursor_action() {
+    g_ext_id = register_branch_extension(new recursor_branch_extension());
+}
+
+void finalize_recursor_action() {
+}
+
+static recursor_branch_extension & get_extension() {
+    return static_cast<recursor_branch_extension&>(curr_state().get_extension(g_ext_id));
+}
+
 optional<name> is_recursor_action_target(hypothesis_idx hidx) {
     state & s = curr_state();
     hypothesis const * h = s.get_hypothesis_decl(hidx);
@@ -312,7 +334,8 @@ action_result recursor_preprocess_action(hypothesis_idx hidx) {
             if (!is_recursive_recursor(*R)) {
                 // TODO(Leo): we need a better strategy for handling recursive recursors...
                 w += static_cast<double>(num_minor);
-                curr_state().add_to_rec_queue(hidx, w);
+                recursor_branch_extension & ext = get_extension();
+                ext.m_rec_queue.insert(w, hidx);
                 return action_result::new_branch();
             }
         }
@@ -321,11 +344,17 @@ action_result recursor_preprocess_action(hypothesis_idx hidx) {
 }
 
 action_result recursor_action() {
-    while (auto hidx = curr_state().select_rec_hypothesis()) {
-        if (optional<name> R = is_recursor_action_target(*hidx)) {
-            Try(recursor_action(*hidx, *R));
+    recursor_branch_extension & ext = get_extension();
+    while (true) {
+        if (ext.m_rec_queue.empty())
+            return action_result::failed();
+        unsigned hidx             = ext.m_rec_queue.erase_min();
+        hypothesis const * h_decl = curr_state().get_hypothesis_decl(hidx);
+        if (h_decl->is_dead())
+            continue;
+        if (optional<name> R = is_recursor_action_target(hidx)) {
+            Try(recursor_action(hidx, *R));
         }
     }
-    return action_result::failed();
 }
 }}

src/library/blast/recursor_action.h

@@ -11,4 +11,7 @@ namespace lean {
 namespace blast {
 action_result recursor_preprocess_action(hypothesis_idx hidx);
 action_result recursor_action();
+
+void initialize_recursor_action();
+void finalize_recursor_action();
 }}

src/library/blast/state.cpp

@@ -64,6 +64,10 @@ static extension_manager & get_extension_manager() {
     return *g_extension_manager;
 }
 
+unsigned register_branch_extension(branch_extension * initial) {
+    return get_extension_manager().register_extension(initial);
+}
+
 branch::branch() {
     unsigned n = get_extension_manager().get_num_extensions();
     m_extensions = new branch_extension*[n];
@@ -85,7 +89,6 @@ branch::branch(branch const & b):
     m_assumption(b.m_assumption),
     m_active(b.m_active),
     m_todo_queue(b.m_todo_queue),
-    m_rec_queue(b.m_rec_queue),
     m_head_to_hyps(b.m_head_to_hyps),
     m_forward_deps(b.m_forward_deps),
     m_target(b.m_target),
@@ -105,7 +108,6 @@ branch::branch(branch && b):
     m_assumption(std::move(b.m_assumption)),
     m_active(std::move(b.m_active)),
     m_todo_queue(std::move(b.m_todo_queue)),
-    m_rec_queue(std::move(b.m_rec_queue)),
     m_head_to_hyps(std::move(b.m_head_to_hyps)),
     m_forward_deps(std::move(b.m_forward_deps)),
     m_target(std::move(b.m_target)),
@@ -124,7 +126,6 @@ void branch::swap(branch & b) {
     std::swap(m_assumption, b.m_assumption);
     std::swap(m_active, b.m_active);
     std::swap(m_todo_queue, b.m_todo_queue);
-    std::swap(m_rec_queue, b.m_rec_queue);
     std::swap(m_head_to_hyps, b.m_head_to_hyps);
     std::swap(m_forward_deps, b.m_forward_deps);
     std::swap(m_target, b.m_target);
@@ -761,21 +762,6 @@ optional<unsigned> state::activate_hypothesis() {
     }
 }
 
-optional<unsigned> state::select_rec_hypothesis() {
-    while (true) {
-        if (m_branch.m_rec_queue.empty())
-            return optional<unsigned>();
-        unsigned hidx             = m_branch.m_rec_queue.erase_min();
-        hypothesis const * h_decl = get_hypothesis_decl(hidx);
-        if (!h_decl->is_dead())
-            return optional<unsigned>(hidx);
-    }
-}
-
-void state::add_to_rec_queue(hypothesis_idx hidx, double w) {
-    m_branch.m_rec_queue.insert(w, hidx);
-}
-
 bool state::hidx_depends_on(unsigned hidx_user, unsigned hidx_provider) const {
     if (auto s = m_branch.m_forward_deps.find(hidx_provider)) {
         return s->contains(hidx_user);

src/library/blast/state.h

@@ -116,13 +116,7 @@ class branch {
     friend class state;
 
     typedef hypothesis_idx_map<hypothesis_idx_set> forward_deps;
-    /* trick to make sure the rb_map::erase_min removes the hypothesis with biggest weight */
-    struct inv_double_cmp {
-        int operator()(double const & d1, double const & d2) const { return d1 > d2 ? -1 : (d1 < d2 ? 1 : 0); }
-    };
-    typedef rb_map<double, hypothesis_idx, inv_double_cmp>   priority_queue;
-    typedef priority_queue                                   todo_queue;
-    typedef priority_queue                                   rec_queue;
+    typedef hypothesis_priority_queue              todo_queue;
 
     // Hypothesis/facts in the current state
     hypothesis_decls   m_hyp_decls;
@@ -144,7 +138,6 @@ class branch {
     hypothesis_idx_set       m_assumption;
     hypothesis_idx_set       m_active;
     todo_queue               m_todo_queue;
-    rec_queue                m_rec_queue;    // priority queue for hypothesis we want to eliminate/recurse
     head_map<hypothesis_idx> m_head_to_hyps;
     forward_deps             m_forward_deps; // given an entry (h -> {h_1, ..., h_n}), we have that each h_i uses h.
     expr                     m_target;
@@ -289,10 +282,6 @@ public:
     /** \brief Activate the next hypothesis in the TODO queue, return none if the TODO queue is empty. */
     optional<hypothesis_idx> activate_hypothesis();
 
-    /** \brief Pick next hypothesis from the rec queue */
-    optional<hypothesis_idx> select_rec_hypothesis();
-    void add_to_rec_queue(hypothesis_idx hidx, double w);
-
     /** \brief Store in \c r the hypotheses in this branch sorted by dependency depth */
     void get_sorted_hypotheses(hypothesis_idx_buffer & r) const;
     /** \brief Sort hypotheses in r */