summaryrefslogtreecommitdiff
path: root/src/xmlpatterns/functions/qfunctionsignature_p.h
blob: 80e786c22a7666c270ad16b79325c0b92fdb850d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
/****************************************************************************
**
** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
** All rights reserved.
** Contact: Nokia Corporation (qt-info@nokia.com)
**
** This file is part of the QtXmlPatterns module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** GNU Lesser General Public License Usage
** This file may be used under the terms of the GNU Lesser General Public
** License version 2.1 as published by the Free Software Foundation and
** appearing in the file LICENSE.LGPL included in the packaging of this
** file. Please review the following information to ensure the GNU Lesser
** General Public License version 2.1 requirements will be met:
** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** In addition, as a special exception, Nokia gives you certain additional
** rights. These rights are described in the Nokia Qt LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU General
** Public License version 3.0 as published by the Free Software Foundation
** and appearing in the file LICENSE.GPL included in the packaging of this
** file. Please review the following information to ensure the GNU General
** Public License version 3.0 requirements will be met:
** http://www.gnu.org/copyleft/gpl.html.
**
** Other Usage
** Alternatively, this file may be used in accordance with the terms and
** conditions contained in a signed written agreement between you and Nokia.
**
**
**
**
**
** $QT_END_LICENSE$
**
****************************************************************************/

//
//  W A R N I N G
//  -------------
//
// This file is not part of the Qt API.  It exists purely as an
// implementation detail.  This header file may change from version to
// version without notice, or even be removed.
//
// We mean it.

#ifndef Patternist_FunctionSignature_H
#define Patternist_FunctionSignature_H

template<typename Key, typename Value> class QHash;
template<typename T> class QList;

#include <QSharedData>

#include "qcalltargetdescription_p.h"
#include "qexpression_p.h"
#include "qfunctionargument_p.h"
#include "qpatternistlocale_p.h"
#include "qprimitives_p.h"

QT_BEGIN_HEADER

QT_BEGIN_NAMESPACE

namespace QPatternist
{

    /**
     * @short Represents the signature of an XPath function.
     *
     * FunctionSignature represents and allows inspection of a function signature,
     * such as <tt>fn:string-join($arg1 as xs:string*, $arg2 as xs:string) as xs:string</tt>.
     * No XPath related languages allows polymorphism on the type of the arguments, only the
     * amount(arity) of the arguments. For example, <tt>fn:string() as xs:string</tt> and
     * <tt>fn:string($arg as item()?) as xs:string</tt> can happily co-exist, but
     * <tt>fn:string($arg as item()?) as xs:string</tt> and
     * <tt>fn:string($arg as xs:anyAtomicType?) as xs:string</tt> would be an error. This
     * fact is reflected by FunctionSignature that if minimumArguments() and maximumArguments()
     * are not equal, it means that this FunctionSignature represents several
     * function signatures.
     *
     * @ingroup Patternist_functions
     * @see <a href="http://www.w3.org/TR/xpath-functions/#func-signatures">XQuery 1.0 and
     * XPath 2.0 Functions and Operators, 1.4 Function Signatures and Descriptions</a>
     * @see <a href="http://en.wikipedia.org/wiki/Arity">Wikipedia, the free encyclopedia, Arity</a>
     * @author Frans Englich <frans.englich@nokia.com>
     */
    class Q_AUTOTEST_EXPORT FunctionSignature : public CallTargetDescription
    {
    public:
        enum
        {
            /**
             * Flags the function as allowing an unlimited amount of arguments.
             */
            UnlimitedArity = -1
        };

        typedef QExplicitlySharedDataPointer<FunctionSignature> Ptr;
        typedef QHash<QXmlName, FunctionSignature::Ptr> Hash;
        typedef QList<FunctionSignature::Ptr> List;

        /**
         * A number which tells the amount of arguments a function has.
         */
        typedef qint16 Arity;

        FunctionSignature(const QXmlName name,
                          const Arity minArgs,
                          const Arity maxArgs,
                          const SequenceType::Ptr &returnType,
                          const Expression::Properties chars = Expression::Properties(),
                          const Expression::ID id = Expression::IDIgnorableExpression);

        void setArguments(const FunctionArgument::List &args);
        FunctionArgument::List arguments() const;

        /**
         * This is a convenience function. Calling this once, is equal to
         * calling setArguments() with a list containing a FunctionsArgument with name @p name
         * and type @p type.
         */
        void appendArgument(const QXmlName::LocalNameCode name,
                            const SequenceType::Ptr &type);

        /**
         * Checks whether @p arity is within the range of allowed count of arguments. For example,
         * when the minimum arguments is 1 and maximum arguments 2, @c false will be returned for
         * passing 0 while @c true will be returned when 2 is passed.
         */
        bool isArityValid(const xsInteger arity) const;

        Arity minimumArguments() const;
        Arity maximumArguments() const;

        /**
         * The return type of this function signature. For example, if the represented function
         * signature is <tt>fn:string() as xs:string</tt>, the return type is <tt>xs:string</tt>.
         */
        SequenceType::Ptr returnType() const;

        /**
         * The properties that the corresponding FunctionCall instance should return in
         * Expression::properties().
         */
        Expression::Properties properties() const;

        /**
         * Determines whether this FunctionSignature is equal to @p other, taking
         * into account XPath's function polymorphism. @p other is equal to this
         * FunctionSignature if their name() instances are equal, and that the maximumArguments()
         * and minimumArguments() arguments of @p other are allowed, as per isArityValid().
         *
         * In other words, this equalness operator can return @c true for different
         * signatures, but it do make sense since a FunctionSignature can represent
         * multiple signatures.
         *
         * @returns @c true if this FunctionSignature is equal to @p other, otherwise @c false
         */
        bool operator==(const FunctionSignature &other) const;

        /**
         * Builds a string representation for this function signature. The syntax
         * used is the one used in the XQuery. It looks like this:
         *
         * <tt>prefix:function-name($parameter-name as parameter-type, ...) as return-type</tt>
         *
         * The prefix used for the name is conventional. For example, for constructor functions
         * is @c xs used.
         *
         * @see <a href="http://www.w3.org/TR/xpath-functions/#func-signatures">XQuery 1.0 and
         * XPath 2.0 Functions and Operators, 1.4 Function Signatures and Descriptions</a>
         */
        QString displayName(const NamePool::Ptr &np) const;

        /**
         * The ID that the corresponding FunctionCall instance should return in
         * Expression::id().
         */
        Expression::ID id() const;

    private:
        Q_DISABLE_COPY(FunctionSignature)

        const Arity                     m_minArgs;
        const Arity                     m_maxArgs;
        const SequenceType::Ptr         m_returnType;
        FunctionArgument::List          m_arguments;
        const Expression::Properties    m_props;
        const Expression::ID            m_id;
    };

    /**
     * @short Formats FunctionSignature.
     */
    static inline QString formatFunction(const NamePool::Ptr &np, const FunctionSignature::Ptr &func)
    {
        return QLatin1String("<span class='XQuery-function'>")  +
               escape(func->displayName(np))                    +
               QLatin1String("</span>");
    }
}

QT_END_NAMESPACE

QT_END_HEADER

#endif