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78 lines
2.4 KiB
C++
78 lines
2.4 KiB
C++
/*++
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Copyright (c) 2021 Microsoft Corporation
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Module Name:
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polysat clauses
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Author:
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Nikolaj Bjorner (nbjorner) 2021-03-19
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Jakob Rath 2021-04-06
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--*/
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#pragma once
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#include "math/polysat/boolean.h"
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#include "math/polysat/types.h"
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namespace polysat {
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class signed_constraint;
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class simplify_clause;
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/// Disjunction of constraints represented by boolean literals
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// NB code review:
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// right, ref-count is unlikely the right mechanism.
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// In the SAT solver all clauses are managed in one arena (auxiliarary and redundant)
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// and deleted when they exist the arena.
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//
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class clause {
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public:
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static inline const bool redundant_default = true;
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private:
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friend class constraint_manager;
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friend class simplify_clause;
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unsigned m_ref_count = 0; // TODO: remove refcount once we confirm it's not needed anymore
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bool m_redundant = redundant_default;
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sat::literal_vector m_literals;
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/* TODO: embed literals to save an indirection?
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unsigned m_num_literals;
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constraint* m_literals[0];
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static size_t object_size(unsigned m_num_literals) {
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return sizeof(clause) + m_num_literals * sizeof(constraint*);
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}
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*/
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clause(sat::literal_vector literals):
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m_literals(std::move(literals)) {
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SASSERT(count(m_literals, sat::null_literal) == 0);
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}
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public:
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void inc_ref() { m_ref_count++; }
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void dec_ref() { SASSERT(m_ref_count > 0); m_ref_count--; if (!m_ref_count) dealloc(this); }
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static clause_ref from_unit(signed_constraint c);
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static clause_ref from_literals(sat::literal_vector literals);
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bool empty() const { return m_literals.empty(); }
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unsigned size() const { return m_literals.size(); }
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sat::literal operator[](unsigned idx) const { return m_literals[idx]; }
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sat::literal& operator[](unsigned idx) { return m_literals[idx]; }
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using const_iterator = typename sat::literal_vector::const_iterator;
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const_iterator begin() const { return m_literals.begin(); }
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const_iterator end() const { return m_literals.end(); }
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std::ostream& display(std::ostream& out) const;
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void set_redundant(bool r) { m_redundant = r; }
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bool is_redundant() const { return m_redundant; }
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};
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inline std::ostream& operator<<(std::ostream& out, clause const& c) { return c.display(out); }
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}
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