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39 | |
40 | #include "qbuiltintypes_p.h" |
41 | #include "qcommonsequencetypes_p.h" |
42 | #include "qcommonvalues_p.h" |
43 | #include "qebvextractor_p.h" |
44 | #include "qitem_p.h" |
45 | #include "qliteral_p.h" |
46 | #include "qoptimizationpasses_p.h" |
47 | #include "quntypedatomicconverter_p.h" |
48 | #include "qvaluecomparison_p.h" |
49 | |
50 | #include "qgeneralcomparison_p.h" |
51 | |
52 | QT_BEGIN_NAMESPACE |
53 | |
54 | using namespace QPatternist; |
55 | |
56 | GeneralComparison::GeneralComparison(const Expression::Ptr &op1, |
57 | const AtomicComparator::Operator op, |
58 | const Expression::Ptr &op2, |
59 | const bool isBackwardsCompat) : PairContainer(op1, op2) |
60 | , m_operator(op) |
61 | , m_isBackwardsCompat(isBackwardsCompat) |
62 | { |
63 | } |
64 | |
65 | /*! \internal */ |
66 | GeneralComparison::~GeneralComparison() |
67 | { |
68 | } |
69 | |
70 | bool GeneralComparison::generalCompare(const Item &op1, |
71 | const Item &op2, |
72 | const DynamicContext::Ptr &context) const |
73 | { |
74 | Q_ASSERT(op1); |
75 | Q_ASSERT(op2); |
76 | |
77 | if(comparator()) |
78 | return compare(oand1: op1, oand2: op2, comp: comparator(), op: m_operator); |
79 | |
80 | Expression::Ptr a1(new Literal(op1)); |
81 | Expression::Ptr a2(new Literal(op2)); |
82 | |
83 | const AtomicComparator::Ptr comp(fetchGeneralComparator(op1&: a1, op2&: a2, context)); |
84 | /* The fetchGeneralComparator call may rewrite a1 and/or a2. */ |
85 | Q_ASSERT(a1); |
86 | Q_ASSERT(a2); |
87 | Q_ASSERT(comp); |
88 | |
89 | return compare(oand1: a1->evaluateSingleton(context), |
90 | oand2: a2->evaluateSingleton(context), |
91 | comp, |
92 | op: m_operator); |
93 | } |
94 | |
95 | bool GeneralComparison::evaluateEBV(const DynamicContext::Ptr &context) const |
96 | { |
97 | const Item::Iterator::Ptr it1(m_operand1->evaluateSequence(context)); |
98 | Item item1(it1->next()); |
99 | |
100 | if(!item1) |
101 | return false; |
102 | |
103 | const Item::Iterator::Ptr it2(m_operand2->evaluateSequence(context)); |
104 | Item::List cache; |
105 | Item item2; |
106 | |
107 | while(true) |
108 | { |
109 | item2 = it2->next(); |
110 | if(!item2) |
111 | break; |
112 | |
113 | if(generalCompare(op1: item1, op2: item2, context)) |
114 | return true; |
115 | |
116 | cache.append(t: item2); |
117 | } |
118 | |
119 | while(true) |
120 | { |
121 | item1 = it1->next(); |
122 | |
123 | if(!item1) |
124 | return false; |
125 | |
126 | const Item::List::const_iterator end(cache.constEnd()); |
127 | Item::List::const_iterator it(cache.constBegin()); |
128 | |
129 | for(; it != end; ++it) |
130 | if(generalCompare(op1: item1, op2: *it, context)) |
131 | return true; |
132 | } |
133 | |
134 | Q_ASSERT(false); |
135 | return false; |
136 | } |
137 | |
138 | Expression::Ptr GeneralComparison::compress(const StaticContext::Ptr &context) |
139 | { |
140 | const Expression::Ptr me(PairContainer::compress(context)); |
141 | |
142 | if(me != this) |
143 | return me; |
144 | |
145 | if(ValueComparison::isCaseInsensitiveCompare(op1&: m_operand1, op2&: m_operand2)) |
146 | useCaseInsensitiveComparator(); |
147 | |
148 | return me; |
149 | } |
150 | |
151 | Expression::Ptr GeneralComparison::typeCheck(const StaticContext::Ptr &context, |
152 | const SequenceType::Ptr &reqType) |
153 | { |
154 | |
155 | const Expression::Ptr me(PairContainer::typeCheck(context, reqType)); |
156 | |
157 | const ItemType::Ptr t1(m_operand1->staticType()->itemType()); |
158 | const ItemType::Ptr t2(m_operand2->staticType()->itemType()); |
159 | |
160 | if(*CommonSequenceTypes::Empty == *t1 || |
161 | *CommonSequenceTypes::Empty == *t2) |
162 | { |
163 | return wrapLiteral(item: CommonValues::BooleanFalse, context, r: this); |
164 | } |
165 | |
166 | if(*BuiltinTypes::xsAnyAtomicType == *t1 || |
167 | *BuiltinTypes::xsAnyAtomicType == *t2) |
168 | return me; |
169 | |
170 | prepareComparison(c: fetchGeneralComparator(op1&: m_operand1, op2&: m_operand2, context)); |
171 | |
172 | if(!m_operand1->staticType()->cardinality().allowsMany() && |
173 | !m_operand2->staticType()->cardinality().allowsMany()) |
174 | { |
175 | /* Rewrite to a ValueComparison whose operands uses typing rules |
176 | * as for an general comparison(that's what's done above). */ |
177 | return rewrite(to: Expression::Ptr(new ValueComparison(m_operand1, |
178 | m_operator, |
179 | m_operand2))->typeCheck(context, reqType), |
180 | context); |
181 | } |
182 | else |
183 | return me; |
184 | } |
185 | |
186 | void GeneralComparison::updateType(ItemType::Ptr &type, |
187 | const Expression::Ptr &source) |
188 | { |
189 | type = source->staticType()->itemType(); |
190 | } |
191 | |
192 | AtomicComparator::Ptr GeneralComparison::fetchGeneralComparator(Expression::Ptr &op1, |
193 | Expression::Ptr &op2, |
194 | const ReportContext::Ptr &context) const |
195 | { |
196 | ItemType::Ptr t1(op1->staticType()->itemType()); |
197 | ItemType::Ptr t2(op2->staticType()->itemType()); |
198 | |
199 | /* a. "If one of the atomic values is an instance of xs:untypedAtomic and |
200 | * the other is an instance of a numeric type, then the xs:untypedAtomic |
201 | * value is cast to the type xs:double." */ |
202 | if(BuiltinTypes::numeric->xdtTypeMatches(other: t1) && |
203 | BuiltinTypes::xsUntypedAtomic->xdtTypeMatches(other: t2)) |
204 | { |
205 | op2 = Expression::Ptr(new UntypedAtomicConverter(op2, BuiltinTypes::xsDouble)); |
206 | |
207 | /* The types might have changed, reload. */ |
208 | updateType(type&: t2, source: op2); |
209 | } |
210 | else if(BuiltinTypes::numeric->xdtTypeMatches(other: t2) && |
211 | BuiltinTypes::xsUntypedAtomic->xdtTypeMatches(other: t1)) |
212 | { |
213 | op1 = Expression::Ptr(new UntypedAtomicConverter(op1, BuiltinTypes::xsDouble)); |
214 | |
215 | /* The types might have changed, reload. */ |
216 | updateType(type&: t1, source: op1); |
217 | } |
218 | /* "If XPath 1.0 compatibility mode is true, a general comparison is |
219 | * evaluated by applying the following rules, in order: |
220 | * 1. If either operand is a single atomic value that is an instance of |
221 | * xs:boolean, then the other operand is converted to xs:boolean by taking |
222 | * its effective boolean value." |
223 | * |
224 | * Notably, it's not conversion to boolean, it is EBV extraction. |
225 | */ |
226 | else if(m_isBackwardsCompat && BuiltinTypes::xsBoolean->xdtTypeMatches(other: t1)) |
227 | { |
228 | op2 = Expression::Ptr(new EBVExtractor(op2)); |
229 | updateType(type&: t2, source: op2); |
230 | } |
231 | else if(m_isBackwardsCompat && BuiltinTypes::xsBoolean->xdtTypeMatches(other: t2)) |
232 | { |
233 | op1 = Expression::Ptr(new EBVExtractor(op1)); |
234 | updateType(type&: t1, source: op1); |
235 | } |
236 | /* b. "If one of the atomic values is an instance of xs:untypedAtomic and |
237 | * the other is an instance of xs:untypedAtomic or xs:string, then the |
238 | * xs:untypedAtomic value (or values) is (are) cast to the type xs:string." |
239 | * |
240 | * c. "If one of the atomic values is an instance of xs:untypedAtomic and the |
241 | * other is not an instance of xs:string, xs:untypedAtomic, or any numeric |
242 | * type, then the xs:untypedAtomic value is cast to the dynamic type of the |
243 | * other value." */ |
244 | else if(BuiltinTypes::xsUntypedAtomic->xdtTypeMatches(other: t1) && |
245 | !BuiltinTypes::xsString->xdtTypeMatches(other: t2) && |
246 | !BuiltinTypes::xsUntypedAtomic->xdtTypeMatches(other: t2) && |
247 | !BuiltinTypes::xsAnyURI->xdtTypeMatches(other: t2)) |
248 | { |
249 | op1 = Expression::Ptr(new UntypedAtomicConverter(op1, t2)); |
250 | updateType(type&: t1, source: op1); |
251 | } |
252 | else if(BuiltinTypes::xsUntypedAtomic->xdtTypeMatches(other: t2) && |
253 | !BuiltinTypes::xsString->xdtTypeMatches(other: t1) && |
254 | !BuiltinTypes::xsUntypedAtomic->xdtTypeMatches(other: t1) && |
255 | !BuiltinTypes::xsAnyURI->xdtTypeMatches(other: t1)) |
256 | { |
257 | op2 = Expression::Ptr(new UntypedAtomicConverter(op2, t1)); |
258 | updateType(type&: t2, source: op2); |
259 | } |
260 | |
261 | /* d. "After performing the conversions described above, the atomic |
262 | * values are compared using one of the value comparison operators |
263 | * eq, ne, lt, le, gt, or ge, depending on whether the general comparison |
264 | * operator was =, !=, <, <=, >, or >=. The values have the required |
265 | * magnitude relationship if and only if the result of this value comparison |
266 | * is true." */ |
267 | |
268 | return fetchComparator(t1, t2, context); |
269 | } |
270 | |
271 | OptimizationPass::List GeneralComparison::optimizationPasses() const |
272 | { |
273 | Q_ASSERT(!OptimizationPasses::comparisonPasses.isEmpty()); |
274 | return OptimizationPasses::comparisonPasses; |
275 | } |
276 | |
277 | SequenceType::List GeneralComparison::expectedOperandTypes() const |
278 | { |
279 | SequenceType::List result; |
280 | result.append(t: CommonSequenceTypes::ZeroOrMoreAtomicTypes); |
281 | result.append(t: CommonSequenceTypes::ZeroOrMoreAtomicTypes); |
282 | return result; |
283 | } |
284 | |
285 | SequenceType::Ptr GeneralComparison::staticType() const |
286 | { |
287 | return CommonSequenceTypes::ExactlyOneBoolean; |
288 | } |
289 | |
290 | ExpressionVisitorResult::Ptr GeneralComparison::accept(const ExpressionVisitor::Ptr &visitor) const |
291 | { |
292 | return visitor->visit(this); |
293 | } |
294 | |
295 | Expression::ID GeneralComparison::id() const |
296 | { |
297 | return IDGeneralComparison; |
298 | } |
299 | |
300 | QT_END_NAMESPACE |
301 | |