z3-z3-4.13.0.src.model.seq_factory.h Maven / Gradle / Ivy
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/*++
Copyright (c) 2011 Microsoft Corporation
Module Name:
seq_factory.h
Author:
Nikolaj Bjorner (nbjorner) 2011-14-11
--*/
#pragma once
#include "ast/seq_decl_plugin.h"
#include "model/model_core.h"
#include "model/value_factory.h"
class seq_factory : public value_factory {
typedef hashtable symbol_set;
model_core& m_model;
seq_util u;
symbol_set m_strings;
unsigned m_next;
std::string m_unique_delim;
obj_map m_unique_sequences;
expr_ref_vector m_trail;
public:
seq_factory(ast_manager & m, family_id fid, model_core& md):
value_factory(m, fid),
m_model(md),
u(m),
m_next(0),
m_unique_delim("!"),
m_trail(m)
{
m_strings.insert(symbol(""));
m_strings.insert(symbol("a"));
m_strings.insert(symbol("b"));
}
void add_trail(expr* e) {
m_trail.push_back(e);
}
void set_prefix(char const* p) {
m_unique_delim = p;
}
// generic method for setting unique sequences
void set_prefix(expr* uniq) {
m_trail.push_back(uniq);
m_unique_sequences.insert(uniq->get_sort(), uniq);
}
expr* get_some_value(sort* s) override {
sort* seq = nullptr;
if (u.is_seq(s))
return u.str.mk_empty(s);
if (u.is_re(s, seq))
return u.re.mk_to_re(u.str.mk_empty(seq));
if (u.is_char(s))
return u.mk_char('A');
UNREACHABLE();
return nullptr;
}
bool get_some_values(sort* s, expr_ref& v1, expr_ref& v2) override {
if (u.is_string(s)) {
v1 = u.str.mk_string("a");
v2 = u.str.mk_string("b");
return true;
}
sort* ch;
if (u.is_seq(s, ch)) {
if (m_model.get_some_values(ch, v1, v2)) {
v1 = u.str.mk_unit(v1);
v2 = u.str.mk_unit(v2);
return true;
}
else {
return false;
}
}
if (u.is_char(s)) {
v1 = u.mk_char('a');
v2 = u.mk_char('b');
return true;
}
return false;
}
expr* get_fresh_value(sort* s) override {
if (u.is_string(s)) {
while (true) {
std::ostringstream strm;
strm << m_unique_delim << std::hex << m_next++ << std::dec << m_unique_delim;
std::string s(strm.str());
symbol sym(s);
if (m_strings.contains(sym)) continue;
m_strings.insert(sym);
return u.str.mk_string(s);
}
}
sort* seq = nullptr, *ch = nullptr;
if (u.is_re(s, seq)) {
expr* v0 = get_fresh_value(seq);
return u.re.mk_to_re(v0);
}
if (u.is_char(s)) {
return u.mk_char('a');
}
if (u.is_seq(s, ch)) {
expr* v = m_model.get_fresh_value(ch);
if (v) {
return u.str.mk_unit(v);
}
else {
v = u.str.mk_unit(m_model.get_some_value(ch));
expr* uniq = nullptr;
if (m_unique_sequences.find(s, uniq)) {
uniq = u.str.mk_concat(v, uniq);
}
else {
uniq = v;
}
m_trail.push_back(uniq);
m_unique_sequences.insert(s, uniq);
return uniq;
}
}
UNREACHABLE();
return nullptr;
}
void register_value(expr* n) override {
zstring s;
if (u.str.is_string(n, s)) {
symbol sym(s.encode());
m_strings.insert(sym);
if (sym.str().find(m_unique_delim) != std::string::npos)
add_new_delim();
}
}
private:
void add_new_delim() {
try_again:
m_unique_delim += "!";
for (auto const& s : m_strings)
if (s.str().find(m_unique_delim) != std::string::npos)
goto try_again;
}
};