1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
|
/******************************************************************************
* Top contributors (to current version):
* Andrew Reynolds, Tianyi Liang, Aina Niemetz
*
* This file is part of the cvc5 project.
*
* Copyright (c) 2009-2021 by the authors listed in the file AUTHORS
* in the top-level source directory and their institutional affiliations.
* All rights reserved. See the file COPYING in the top-level source
* directory for licensing information.
* ****************************************************************************
*
* Implementation of a finite model finding decision strategy for strings.
*/
#include "theory/strings/strings_fmf.h"
#include "util/rational.h"
using namespace std;
using namespace cvc5::context;
using namespace cvc5::kind;
namespace cvc5 {
namespace theory {
namespace strings {
StringsFmf::StringsFmf(Env& env, Valuation valuation, TermRegistry& tr)
: EnvObj(env), d_sslds(nullptr), d_valuation(valuation), d_termReg(tr)
{
}
StringsFmf::~StringsFmf() {}
void StringsFmf::presolve()
{
d_sslds.reset(new StringSumLengthDecisionStrategy(d_env, d_valuation));
Trace("strings-dstrat-reg")
<< "presolve: register decision strategy." << std::endl;
const NodeSet& ivars = d_termReg.getInputVars();
std::vector<Node> inputVars;
for (NodeSet::const_iterator itr = ivars.begin(); itr != ivars.end(); ++itr)
{
inputVars.push_back(*itr);
}
d_sslds->initialize(inputVars);
}
DecisionStrategy* StringsFmf::getDecisionStrategy() const
{
return d_sslds.get();
}
StringsFmf::StringSumLengthDecisionStrategy::StringSumLengthDecisionStrategy(
Env& env, Valuation valuation)
: DecisionStrategyFmf(env, valuation), d_inputVarLsum(userContext())
{
}
bool StringsFmf::StringSumLengthDecisionStrategy::isInitialized()
{
return !d_inputVarLsum.get().isNull();
}
void StringsFmf::StringSumLengthDecisionStrategy::initialize(
const std::vector<Node>& vars)
{
if (d_inputVarLsum.get().isNull() && !vars.empty())
{
NodeManager* nm = NodeManager::currentNM();
std::vector<Node> sum;
for (const Node& v : vars)
{
sum.push_back(nm->mkNode(STRING_LENGTH, v));
}
Node sumn = sum.size() == 1 ? sum[0] : nm->mkNode(PLUS, sum);
d_inputVarLsum.set(sumn);
}
}
Node StringsFmf::StringSumLengthDecisionStrategy::mkLiteral(unsigned i)
{
if (d_inputVarLsum.get().isNull())
{
return Node::null();
}
NodeManager* nm = NodeManager::currentNM();
Node lit = nm->mkNode(LEQ, d_inputVarLsum.get(), nm->mkConstInt(Rational(i)));
Trace("strings-fmf") << "StringsFMF::mkLiteral: " << lit << std::endl;
return lit;
}
std::string StringsFmf::StringSumLengthDecisionStrategy::identify() const
{
return std::string("string_sum_len");
}
} // namespace strings
} // namespace theory
} // namespace cvc5
|
