1 | /**************************************************************************** |
2 | ** |
3 | ** Copyright (C) 2016 The Qt Company Ltd. |
4 | ** Contact: https://www.qt.io/licensing/ |
5 | ** |
6 | ** This file is part of the QtXmlPatterns module of the Qt Toolkit. |
7 | ** |
8 | ** $QT_BEGIN_LICENSE:LGPL$ |
9 | ** Commercial License Usage |
10 | ** Licensees holding valid commercial Qt licenses may use this file in |
11 | ** accordance with the commercial license agreement provided with the |
12 | ** Software or, alternatively, in accordance with the terms contained in |
13 | ** a written agreement between you and The Qt Company. For licensing terms |
14 | ** and conditions see https://www.qt.io/terms-conditions. For further |
15 | ** information use the contact form at https://www.qt.io/contact-us. |
16 | ** |
17 | ** GNU Lesser General Public License Usage |
18 | ** Alternatively, this file may be used under the terms of the GNU Lesser |
19 | ** General Public License version 3 as published by the Free Software |
20 | ** Foundation and appearing in the file LICENSE.LGPL3 included in the |
21 | ** packaging of this file. Please review the following information to |
22 | ** ensure the GNU Lesser General Public License version 3 requirements |
23 | ** will be met: https://www.gnu.org/licenses/lgpl-3.0.html. |
24 | ** |
25 | ** GNU General Public License Usage |
26 | ** Alternatively, this file may be used under the terms of the GNU |
27 | ** General Public License version 2.0 or (at your option) the GNU General |
28 | ** Public license version 3 or any later version approved by the KDE Free |
29 | ** Qt Foundation. The licenses are as published by the Free Software |
30 | ** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3 |
31 | ** included in the packaging of this file. Please review the following |
32 | ** information to ensure the GNU General Public License requirements will |
33 | ** be met: https://www.gnu.org/licenses/gpl-2.0.html and |
34 | ** https://www.gnu.org/licenses/gpl-3.0.html. |
35 | ** |
36 | ** $QT_END_LICENSE$ |
37 | ** |
38 | ****************************************************************************/ |
39 | |
40 | #include "qbuiltintypes_p.h" |
41 | #include "qcommonsequencetypes_p.h" |
42 | #include "qcommonvalues_p.h" |
43 | #include "qgenericsequencetype_p.h" |
44 | #include "qinteger_p.h" |
45 | #include "qliteral_p.h" |
46 | #include "qrangeiterator_p.h" |
47 | |
48 | #include "qrangeexpression_p.h" |
49 | |
50 | QT_BEGIN_NAMESPACE |
51 | |
52 | using namespace QPatternist; |
53 | |
54 | RangeExpression::RangeExpression(const Expression::Ptr &operand1, |
55 | const Expression::Ptr &operand2) : PairContainer(operand1, operand2) |
56 | { |
57 | } |
58 | |
59 | Item::Iterator::Ptr RangeExpression::evaluateSequence(const DynamicContext::Ptr &context) const |
60 | { |
61 | const Item s(m_operand1->evaluateSingleton(context)); |
62 | |
63 | if(!s) |
64 | return CommonValues::emptyIterator; |
65 | |
66 | const Item e(m_operand2->evaluateSingleton(context)); |
67 | if(!e) |
68 | return CommonValues::emptyIterator; |
69 | |
70 | const xsInteger start = s.as<Numeric>()->toInteger(); |
71 | const xsInteger end = e.as<Numeric>()->toInteger(); |
72 | |
73 | if(start > end) |
74 | return CommonValues::emptyIterator; |
75 | else if(start == end) |
76 | return makeSingletonIterator(item: s); |
77 | else |
78 | return Item::Iterator::Ptr(new RangeIterator(start, RangeIterator::Forward, end)); |
79 | } |
80 | |
81 | Item RangeExpression::evaluateSingleton(const DynamicContext::Ptr &context) const |
82 | { |
83 | return m_operand1->evaluateSingleton(context); |
84 | } |
85 | |
86 | SequenceType::List RangeExpression::expectedOperandTypes() const |
87 | { |
88 | SequenceType::List result; |
89 | result.append(t: CommonSequenceTypes::ZeroOrOneInteger); |
90 | result.append(t: CommonSequenceTypes::ZeroOrOneInteger); |
91 | return result; |
92 | } |
93 | |
94 | SequenceType::Ptr RangeExpression::staticType() const |
95 | { |
96 | /* This logic makes the Cardinality more specific. */ |
97 | Cardinality::Count from; |
98 | bool hasFrom; |
99 | |
100 | if(m_operand1->is(i: IDIntegerValue)) |
101 | { |
102 | from = m_operand1->as<Literal>()->item().as<Integer>()->toInteger(); |
103 | hasFrom = true; |
104 | } |
105 | else |
106 | { |
107 | hasFrom = false; |
108 | from = 0; |
109 | } |
110 | |
111 | /* We can't check whether to is -1 since maybe the user wrote -1. Hence |
112 | * hasTo is required. */ |
113 | bool hasTo; |
114 | Cardinality::Count to; |
115 | |
116 | if(m_operand2->is(i: IDIntegerValue)) |
117 | { |
118 | const xsInteger asInt = m_operand2->as<Literal>()->item().as<Integer>()->toInteger(); |
119 | to = asInt; |
120 | |
121 | if(to == asInt) |
122 | hasTo = true; |
123 | else |
124 | { |
125 | /* Cardinality::Count is not the same as type xsInteger. We had overflow. */ |
126 | to = -1; |
127 | hasTo = false; |
128 | } |
129 | } |
130 | else |
131 | { |
132 | to = -1; |
133 | hasTo = false; |
134 | } |
135 | |
136 | if(hasTo && hasFrom) |
137 | { |
138 | if(from > to) |
139 | { |
140 | /* The query is incorrectly written, we'll evaluate to the empty sequence. |
141 | * Just return what's correct. */ |
142 | return CommonSequenceTypes::ZeroOrMoreIntegers; |
143 | } |
144 | else |
145 | { |
146 | Cardinality::Count count = (to - from) + 1; /* + 1, since it's inclusive. */ |
147 | return makeGenericSequenceType(itemType: BuiltinTypes::xsInteger, cardinality: Cardinality::fromExact(count)); |
148 | } |
149 | } |
150 | else |
151 | { |
152 | /* We can't do fromExact(from, -1) since the latter can evaluate to a value that actually is |
153 | * lower than from, although that unfortunately is very unlikely. */ |
154 | return CommonSequenceTypes::ZeroOrMoreIntegers; |
155 | } |
156 | } |
157 | |
158 | Expression::Properties RangeExpression::properties() const |
159 | { |
160 | return Expression::DisableElimination; |
161 | } |
162 | |
163 | ExpressionVisitorResult::Ptr RangeExpression::accept(const ExpressionVisitor::Ptr &visitor) const |
164 | { |
165 | return visitor->visit(this); |
166 | } |
167 | |
168 | QT_END_NAMESPACE |
169 | |