Z3 sources

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

lib/shared_occs.h

@@ -0,0 +1,81 @@
+/*++
+Copyright (c) 2011 Microsoft Corporation
+
+Module Name:
+
+    shared_occs.h
+
+Abstract:
+
+    Functor for computing the shared subterms in a given
+    term.
+
+Author:
+
+    Leonardo de Moura (leonardo) 2011-04-01.
+
+Revision History:
+--*/
+#ifndef _SHARED_OCCS_H_
+#define _SHARED_OCCS_H_
+
+#include"ast.h"
+#include"obj_hashtable.h"
+
+class shared_occs_mark {
+    ptr_buffer<ast> m_to_unmark;
+public:
+    shared_occs_mark() {}
+ 
+    ~shared_occs_mark() {
+        reset();
+    }
+    
+    bool is_marked(ast * n) { return n->is_marked_so(); }
+    void reset_mark(ast * n) { n->reset_mark_so(); }
+    void mark(ast * n) { if (is_marked(n)) return; n->mark_so(true); m_to_unmark.push_back(n); }
+    void reset() {
+        ptr_buffer<ast>::iterator it  = m_to_unmark.begin();
+        ptr_buffer<ast>::iterator end = m_to_unmark.end();
+        for (; it != end; ++it) {
+            reset_mark(*it);
+        }
+        m_to_unmark.reset();
+    }
+    void mark(ast * n, bool flag) { if (flag) mark(n); else reset_mark(n); } 
+};
+
+/**
+   \brief Functor for computing the shared subterms in a given term.
+*/
+class shared_occs {
+    ast_manager &       m;
+    bool                m_track_atomic;
+    bool                m_visit_quantifiers;
+    bool                m_visit_patterns;
+    obj_hashtable<expr> m_shared;
+    typedef std::pair<expr*, unsigned> frame;
+    svector<frame>      m_stack;
+    bool process(expr * t, shared_occs_mark & visited);
+    void insert(expr * t);
+public:
+    typedef obj_hashtable<expr>::iterator iterator;
+    shared_occs(ast_manager & _m, bool track_atomic = false, bool visit_quantifiers = true, bool visit_patterns = false):
+        m(_m),
+        m_track_atomic(track_atomic),
+        m_visit_quantifiers(visit_quantifiers),
+        m_visit_patterns(visit_patterns) {
+    }
+    ~shared_occs();
+    void operator()(expr * t);
+    void operator()(expr * t, shared_occs_mark & visited);
+    bool is_shared(expr * t) const { return m_shared.contains(t); }
+    unsigned num_shared() const { return m_shared.size(); }
+    iterator begin_shared() const { return m_shared.begin(); }
+    iterator end_shared() const { return m_shared.end(); }
+    void reset();
+    void cleanup();
+    void display(std::ostream & out, ast_manager & m) const;
+};
+
+#endif