3
0
Fork 0
mirror of https://github.com/Z3Prover/z3 synced 2025-08-26 04:56:03 +00:00
z3/src/math/polysat/search_state.h
2022-11-21 17:25:15 +01:00

105 lines
3.9 KiB
C++

/*++
Copyright (c) 2021 Microsoft Corporation
Module Name:
polysat search state
Author:
Nikolaj Bjorner (nbjorner) 2021-03-19
Jakob Rath 2021-04-06
--*/
#pragma once
#include "math/polysat/types.h"
#include "math/polysat/assignment.h"
namespace polysat {
enum class search_item_k
{
assignment,
boolean,
};
class search_item {
search_item_k m_kind;
union {
pvar m_var;
sat::literal m_lit;
};
bool m_resolved = false; // when marked as resolved it is no longer valid to reduce the conflict state
search_item(pvar var): m_kind(search_item_k::assignment), m_var(var) {}
search_item(sat::literal lit): m_kind(search_item_k::boolean), m_lit(lit) {}
public:
static search_item assignment(pvar var) { return search_item(var); }
static search_item boolean(sat::literal lit) { return search_item(lit); }
bool is_assignment() const { return m_kind == search_item_k::assignment; }
bool is_boolean() const { return m_kind == search_item_k::boolean; }
bool is_resolved() const { return m_resolved; }
search_item_k kind() const { return m_kind; }
pvar var() const { SASSERT(is_assignment()); return m_var; }
sat::literal lit() const { SASSERT(is_boolean()); return m_lit; }
void set_resolved() { m_resolved = true; }
};
class search_state {
solver& s;
vector<search_item> m_items;
assignment m_assignment;
bool value(pvar v, rational& r) const;
public:
search_state(solver& s): s(s), m_assignment(s) {}
unsigned size() const { return m_items.size(); }
search_item const& back() const { return m_items.back(); }
search_item const& operator[](unsigned i) const { return m_items[i]; }
assignment_t const& assignment() const { return m_assignment; }
substitution const& subst(unsigned sz) const { return m_assignment.subst(sz); }
// TODO: implement the following method if we actually need the assignments without resolved items already during conflict resolution
// (no separate trail needed, just a second m_subst and an index into the trail, I think)
// (update on set_resolved? might be one iteration too early, looking at the old solver::resolve_conflict loop)
substitution const& unresolved_assignment(unsigned sz) const;
void push_assignment(pvar p, rational const& r);
void push_boolean(sat::literal lit);
void pop();
void set_resolved(unsigned i) { m_items[i].set_resolved(); }
using const_iterator = decltype(m_items)::const_iterator;
const_iterator begin() const { return m_items.begin(); }
const_iterator end() const { return m_items.end(); }
std::ostream& display(std::ostream& out) const;
std::ostream& display(search_item const& item, std::ostream& out) const;
std::ostream& display_verbose(std::ostream& out) const;
std::ostream& display_verbose(search_item const& item, std::ostream& out) const;
};
struct search_state_pp {
search_state const& s;
bool verbose;
search_state_pp(search_state const& s, bool verbose = false) : s(s), verbose(verbose) {}
};
struct search_item_pp {
search_state const& s;
search_item const& i;
bool verbose;
search_item_pp(search_state const& s, search_item const& i, bool verbose = false) : s(s), i(i), verbose(verbose) {}
};
inline std::ostream& operator<<(std::ostream& out, search_state const& s) { return s.display(out); }
inline std::ostream& operator<<(std::ostream& out, search_state_pp const& p) { return p.verbose ? p.s.display_verbose(out) : p.s.display(out); }
inline std::ostream& operator<<(std::ostream& out, search_item_pp const& p) { return p.verbose ? p.s.display_verbose(p.i, out) : p.s.display(p.i, out); }
}