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39
40#include "qarithmeticexpression_p.h"
41#include "qcommonvalues_p.h"
42#include "qliteral_p.h"
43#include "qschemanumeric_p.h"
44
45#include "qunaryexpression_p.h"
46
47QT_BEGIN_NAMESPACE
48
49using namespace QPatternist;
50
51UnaryExpression::UnaryExpression(const AtomicMathematician::Operator op,
52 const Expression::Ptr &operand,
53 const StaticContext::Ptr &context) : ArithmeticExpression(wrapLiteral(item: CommonValues::IntegerZero, context, r: operand.data()),
54 op,
55 operand)
56{
57 Q_ASSERT(op == AtomicMathematician::Substract ||
58 op == AtomicMathematician::Add);
59 Q_ASSERT(context);
60}
61
62Item UnaryExpression::evaluateSingleton(const DynamicContext::Ptr &context) const
63{
64 if(operatorID() == AtomicMathematician::Substract)
65 {
66 const Item item(m_operand2->evaluateSingleton(context));
67
68 if (item)
69 // If the item is an untypedAtomic (or atomicString), the cast to Numeric will
70 // return a garbage object and will most likely cause a crash.
71 // There is simply no way to static cast from an instance of AtomicString to a Number.
72 return item.as<Numeric>()->toNegated();
73 else
74 return Item();
75 }
76 else
77 return m_operand2->evaluateSingleton(context);
78}
79
80QT_END_NAMESPACE
81

source code of qtxmlpatterns/src/xmlpatterns/expr/qunaryexpression.cpp