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/********************* */
/*! \file term_context.cpp
** \verbatim
** Top contributors (to current version):
** Andrew Reynolds
** This file is part of the CVC4 project.
** Copyright (c) 2009-2020 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.\endverbatim
**
** \brief Implementation of term context utilities.
**/
#include "expr/term_context.h"
namespace CVC4 {
uint32_t RtfTermContext::initialValue() const
{
// by default, not in a term context or a quantifier
return 0;
}
uint32_t RtfTermContext::computeValue(TNode t,
uint32_t tval,
size_t child) const
{
if (t.isClosure())
{
if (tval % 2 == 0)
{
return tval + 1;
}
}
else if (hasNestedTermChildren(t))
{
if (tval < 2)
{
return tval + 2;
}
}
return tval;
}
uint32_t RtfTermContext::getValue(bool inQuant, bool inTerm)
{
return (inQuant ? 1 : 0) + 2 * (inTerm ? 1 : 0);
}
void RtfTermContext::getFlags(uint32_t val, bool& inQuant, bool& inTerm)
{
inQuant = val % 2 == 1;
inTerm = val >= 2;
}
bool RtfTermContext::hasNestedTermChildren(TNode t)
{
Kind k = t.getKind();
// dont' worry about FORALL or EXISTS, these are part of inQuant.
return theory::kindToTheoryId(k) != theory::THEORY_BOOL && k != kind::EQUAL
&& k != kind::SEP_STAR && k != kind::SEP_WAND && k != kind::SEP_LABEL
&& k != kind::BITVECTOR_EAGER_ATOM;
}
uint32_t PolarityTermContext::initialValue() const
{
// by default, we have true polarity
return 2;
}
uint32_t PolarityTermContext::computeValue(TNode t,
uint32_t tval,
size_t index) const
{
switch (t.getKind())
{
case kind::AND:
case kind::OR:
case kind::SEP_STAR:
// polarity preserved
return tval;
case kind::IMPLIES:
// first child reverses, otherwise we preserve
return index == 0 ? (tval == 0 ? 0 : (3 - tval)) : tval;
case kind::NOT:
// polarity reversed
return tval == 0 ? 0 : (3 - tval);
case kind::ITE:
// head has no polarity, branches preserve
return index == 0 ? 0 : tval;
case kind::FORALL:
// body preserves, others have no polarity.
return index == 1 ? tval : 0;
default:
// no polarity
break;
}
return 0;
}
uint32_t PolarityTermContext::getValue(bool hasPol, bool pol)
{
return hasPol ? (pol ? 2 : 1) : 0;
}
void PolarityTermContext::getFlags(uint32_t val, bool& hasPol, bool& pol)
{
hasPol = val == 0;
pol = val == 2;
}
} // namespace CVC4
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