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39
40#include "qatomictype_p.h"
41#include "qitem_p.h"
42#include "qboolean_p.h"
43#include "qbuiltintypes_p.h"
44#include "qcommonsequencetypes_p.h"
45#include "qcommonvalues_p.h"
46#include "qliteral_p.h"
47
48#include "qcastableas_p.h"
49
50QT_BEGIN_NAMESPACE
51
52using namespace QPatternist;
53
54CastableAs::CastableAs(const Expression::Ptr &operand,
55 const SequenceType::Ptr &tType) : SingleContainer(operand),
56 m_targetType(tType)
57{
58 Q_ASSERT(tType);
59 Q_ASSERT(!tType->cardinality().allowsMany());
60 Q_ASSERT(tType->itemType()->isAtomicType());
61}
62
63bool CastableAs::evaluateEBV(const DynamicContext::Ptr &context) const
64{
65 Item item;
66
67 if(m_operand->staticType()->cardinality().allowsMany())
68 {
69 const Item::Iterator::Ptr it(m_operand->evaluateSequence(context));
70 item = it->next();
71
72 if(it->next())
73 return false;
74 }
75 else
76 item = m_operand->evaluateSingleton(context);
77
78 if(item)
79 return !cast(sourceValue: item, context).as<AtomicValue>()->hasError();
80 else
81 return m_targetType->cardinality().allowsEmpty();
82}
83
84Expression::Ptr CastableAs::compress(const StaticContext::Ptr &context)
85{
86 const Expression::Ptr me(SingleContainer::compress(context));
87
88 if(me != this) /* We already managed to const fold, how convenient. */
89 return me;
90
91 const AtomicType::Ptr t(m_targetType->itemType());
92
93 const SequenceType::Ptr opType(m_operand->staticType());
94
95 /* Casting to these always succeeds, assuming the cardinality also matches,
96 * although the cardinality can fail. */
97 if(( *t == *BuiltinTypes::xsString
98 || *t == *BuiltinTypes::xsUntypedAtomic
99 || *t == *opType->itemType())
100 &&(m_targetType->cardinality().isMatch(other: opType->cardinality())))
101 {
102 return wrapLiteral(item: CommonValues::BooleanTrue, context, r: this);
103 }
104 else
105 return me;
106}
107
108Expression::Ptr CastableAs::typeCheck(const StaticContext::Ptr &context,
109 const SequenceType::Ptr &reqType)
110{
111 checkTargetType(context);
112 const Expression::Ptr me(SingleContainer::typeCheck(context, reqType));
113
114 return me;
115 if(BuiltinTypes::xsQName->xdtTypeMatches(other: m_targetType->itemType()))
116 {
117 const SequenceType::Ptr seqt(m_operand->staticType());
118 /* We can cast a string literal, an xs:QName value, and an
119 * empty sequence(if empty is allowed), to xs:QName. */
120 if(m_operand->is(i: IDStringValue) ||
121 BuiltinTypes::xsQName->xdtTypeMatches(other: seqt->itemType()) ||
122 (*seqt->itemType() == *CommonSequenceTypes::Empty && m_targetType->cardinality().allowsEmpty()))
123 {
124 return wrapLiteral(item: CommonValues::BooleanTrue, context, r: this)->typeCheck(context, reqType);
125 }
126 else
127 return wrapLiteral(item: CommonValues::BooleanFalse, context, r: this)->typeCheck(context, reqType);
128 }
129 else
130 {
131 /* Let the CastingPlatform look up its AtomicCaster. */
132 prepareCasting(context, sourceType: m_operand->staticType()->itemType());
133
134 return me;
135 }
136}
137
138SequenceType::List CastableAs::expectedOperandTypes() const
139{
140 SequenceType::List result;
141 result.append(t: CommonSequenceTypes::ZeroOrMoreAtomicTypes);
142 return result;
143}
144
145SequenceType::Ptr CastableAs::staticType() const
146{
147 return CommonSequenceTypes::ExactlyOneBoolean;
148}
149
150ExpressionVisitorResult::Ptr CastableAs::accept(const ExpressionVisitor::Ptr &visitor) const
151{
152 return visitor->visit(this);
153}
154
155QT_END_NAMESPACE
156

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