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41 
42 //
43 //  W A R N I N G
44 //  -------------
45 //
46 // This file is not part of the Qt API.  It exists purely as an
47 // implementation detail.  This header file may change from version to
48 // version without notice, or even be removed.
49 //
50 // We mean it.
51 
52 #ifndef Patternist_Numeric_H
53 #define Patternist_Numeric_H
54 
55 #include "qitem_p.h"
56 #include "qprimitives_p.h"
57 
58 QT_BEGIN_HEADER
59 
60 QT_BEGIN_NAMESPACE
61 
62 /**
63  * @file
64  * @short Contains class Numeric. This file was originally called qnumeric_p.h,
65  * but various build systems cannot handle that that name happens to be
66  * identical to another one, the one in QtCore.
67  */
68 
69 namespace QPatternist
70 {
71     /**
72      * @short Base class for all numeric values.
73      *
74      * @section creation Creating Instances
75      *
76      * @todo
77      * - Depending on what type of val
78      * - Numeric::createFromString
79      * - Various classes has ::Zero(), ::PosINF(), ::NaN(), NegINF()
80      * - Never use constructor, use createFromNative, or createFromString.
81      *
82      * @see <a href="http://www.w3.org/TR/xquery-operators/#numeric-functions">XQuery 1.0
83      * and XPath 2.0 Functions and Operators, 6 Functions and Operators on Numerics</a>
84      * @see <a href="http://www.w3.org/TR/xquery-operators/#func-overloading">XQuery 1.0
85      * and XPath 2.0 Functions and Operators, 1.2 Function Overloading</a>
86      * @author Frans Englich <frans.englich@nokia.com>
87      * @ingroup Patternist_xdm
88      * @todo discuss data hierarchy the non existatnt number data type
89      */
90     class Numeric : public AtomicValue
91     {
92     public:
93 
94         typedef QExplicitlySharedDataPointer<Numeric> Ptr;
95 
96         /**
97          * Creates a Numeric sub-class that is appropriate for @p number.
98          *
99          * @note usages of e/E is not handled; Double::fromLexical should
100          * be used in that case. There is no function similar to fromLexical that also
101          * takes double values into account(because that distinction is done in the scanner).
102          *
103          * Currently used in the parser to create appropriate expressions.
104          */
105         static AtomicValue::Ptr fromLexical(const QString &number);
106 
107         /**
108          * @returns the particular number's value as a native representation of
109          * the type xs:double. This can be considered that the value is cast to
110          * xs:double.
111          */
112         virtual xsDouble toDouble() const = 0;
113 
114         /**
115          * @returns the particular number's value as a native representation of
116          * the type xs:integer. This can be considered that the value is cast to
117          * xs:integer.
118          */
119         virtual xsInteger toInteger() const = 0;
120 
121         /**
122          * @returns the number as an unsigned integer. If the value is not
123          * unsigned, the code asserts and behavior is undefined.
124          */
125         virtual qulonglong toUnsignedInteger() const = 0;
126 
127         /**
128          * @returns the particular number's value as a native representation of
129          * the type xs:float. This can be considered that the value is cast to
130          * xs:float.
131          */
132         virtual xsFloat toFloat() const = 0;
133 
134         /**
135          * @returns the particular number's value as a native representation of
136          * the type xs:decimal. This can be considered that the value is cast to
137          * xs:decimal.
138          */
139         virtual xsFloat toDecimal() const = 0;
140 
141         /**
142          * Performs the algorithm specified for the function fn:round on this Numeric,
143          * and whose result is returned.
144          *
145          * @see <a href="http://www.w3.org/TR/xpath-functions/#func-round">XQuery 1.0
146          * and XPath 2.0 Functions and Operators, 6.4.4 fn:round</a>
147          */
148         virtual Numeric::Ptr round() const = 0;
149 
150         /**
151          * Performs rounding as defined for the fn:round-half-to-even  on this Numeric,
152          * and whose result is returned.
153          *
154          * @see <a href="http://www.w3.org/TR/xpath-functions/#func-round-half-to-even">XQuery 1.0
155          * and XPath 2.0 Functions and Operators, 6.4.5 fn:round-half-to-even</a>
156          */
157         virtual Numeric::Ptr roundHalfToEven(const xsInteger scale) const = 0;
158 
159         /**
160          * Performs the algorithm specified for the function fn:floor on this Numeric,
161          * and whose result is returned.
162          *
163          * @see <a href="http://www.w3.org/TR/xpath-functions/#func-floor">XQuery 1.0
164          * and XPath 2.0 Functions and Operators, 6.4.3 fn:floor</a>
165          */
166         virtual Numeric::Ptr floor() const = 0;
167 
168         /**
169          * Performs the algorithm specified for the function fn:ceiling on this Numeric,
170          * and whose result is returned.
171          *
172          * @see <a href="http://www.w3.org/TR/xpath-functions/#func-ceiling">XQuery 1.0
173          * and XPath 2.0 Functions and Operators, 6.4.2 fn:ceiling</a>
174          */
175         virtual Numeric::Ptr ceiling() const = 0;
176 
177         /**
178          * Performs the algorithm specified for the function fn:abs on this Numeric,
179          * and whose result is returned.
180          *
181          * @see <a href="http://www.w3.org/TR/xpath-functions/#func-ceiling">XQuery 1.0
182          * and XPath 2.0 Functions and Operators, 6.4.1 fn:abs</a>
183          */
184         virtual Numeric::Ptr abs() const = 0;
185 
186         /**
187          * Determines whether this Numeric is not-a-number, @c NaN. For numeric types
188          * that cannot represent @c NaN, this function should return @c false.
189          *
190          * @returns @c true if this Numeric is @c NaN
191          */
192         virtual bool isNaN() const = 0;
193 
194         /**
195          * Determines whether this Numeric is an infinite number. Signedness
196          * is irrelevant, -INF as well as INF is considered infinity.
197          *
198          * For numeric types that cannot represent infinity, such as xs:integer
199          * , this function should return @c false.
200          *
201          * @returns @c true if this Numeric is an infinite number
202          */
203         virtual bool isInf() const = 0;
204 
205         /**
206          * Unary minus.
207          */
208         virtual Item toNegated() const = 0;
209 
210         /**
211          * @short Returns @c true if this value is signed. If @c false is
212          * returned, the value is unsigned.
213          *
214          * For float and decimal values, @c xs:double, @c xs:float and @c
215          * xs:decimal, the code asserts and behavior is undefined.
216          */
217         virtual bool isSigned() const = 0;
218 
219     protected:
220         /**
221          * @short Implements @c fn:round() for types implemented with floating
222          * point.
223          *
224          * MS Windows and at least IRIX does not have C99's nearbyint() function(see the man
225          * page), so we reinvent it.
226          */
227         static xsDouble roundFloat(const xsDouble val);
228     };
229 }
230 
231 QT_END_NAMESPACE
232 
233 QT_END_HEADER
234 
235 #endif
236