--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/xmlpatterns/expr/qcastingplatform_p.h Mon Jan 11 14:00:40 2010 +0000
@@ -0,0 +1,206 @@
+/****************************************************************************
+**
+** Copyright (C) 2009 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.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** No Commercial Usage
+** This file contains pre-release code and may not be distributed.
+** You may use this file in accordance with the terms and conditions
+** contained in the Technology Preview License Agreement accompanying
+** this package.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, 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.
+**
+** If you have questions regarding the use of this file, please contact
+** Nokia at qt-info@nokia.com.
+**
+**
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+//
+// 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_CastingPlatform_H
+#define Patternist_CastingPlatform_H
+
+#include "qatomiccasterlocator_p.h"
+#include "qatomiccaster_p.h"
+#include "qatomicstring_p.h"
+#include "qatomictype_p.h"
+#include "qbuiltintypes_p.h"
+#include "qcommonsequencetypes_p.h"
+#include "qpatternistlocale_p.h"
+#include "qqnamevalue_p.h"
+#include "qschematypefactory_p.h"
+#include "qstaticcontext_p.h"
+#include "qvalidationerror_p.h"
+
+QT_BEGIN_HEADER
+
+QT_BEGIN_NAMESPACE
+
+namespace QPatternist
+{
+ /**
+ * @short Provides casting functionality for classes, such as CastAs or NumberFN, which
+ * needs to perform casting.
+ *
+ * Classes which need to perform casting can simply from this class and gain
+ * access to casting functinality wrapped in a convenient way. At the center of this
+ * class is the cast() function, which is used at runtime to perform the actual cast.
+ *
+ * The actual circumstances where casting is used, such as in the 'castable as'
+ * expression or the <tt>fn:number()</tt> function, often have other things to handle as well,
+ * error handling and cardinality checks for example. This class handles only casting
+ * and leaves the other case-specific details to the sub-class such that this class only
+ * do one thing well.
+ *
+ * This template class takes two parameters:
+ * - TSubClass This should be the class inheriting from CastingPlatform.
+ * - issueError if true, errors are issued via ReportContext, otherwise
+ * ValidationError instances are returned appropriately.
+ *
+ * The class inheriting CastingPlatform must implement the following function:
+ * @code
+ * ItemType::Ptr targetType() const
+ * @endcode
+ *
+ * that returns the type that should be cast to. The type must be an AtomicType.
+ * Typically, it is appropriate to declare this function @c inline.
+ *
+ * A sub-class calls prepareCasting() at compile time(such that CastingPlatform can attempt
+ * to lookup the proper AtomicCaster) and then it simply uses the cast() function at runtime. The
+ * function targetType() must be implemented such that CastingPlatform knows
+ * what type it shall cast to.
+ *
+ * @see ValueFactory
+ * @author Frans Englich <frans.englich@nokia.com>
+ * @ingroup Patternist_expressions
+ */
+ template<typename TSubClass, const bool issueError>
+ class CastingPlatform
+ {
+ protected:
+ /**
+ * @note issueCastError() depends on the default value.
+ */
+ inline CastingPlatform(const ReportContext::ErrorCode code = ReportContext::FORG0001) : m_errorCode(code)
+ {
+ }
+
+ /**
+ * Attempts to cast @p sourceValue to targetType(), and returns
+ * the created value. Remember that prepareCasting() should have been
+ * called at compile time, otherwise this function will be slow.
+ *
+ * Error reporting is done in two ways. If a cast fails because
+ * of an error in lexical representation a ValidationError is returned.
+ * If the cause of failure is that the casting combination is invalid(such as
+ * when attempting to cast @c xs:date to @c xs:integer), a ValidationError
+ * is returned if @c false was passed in the template instantiation,
+ * an error is issued via @p context.
+ *
+ * @param sourceValue the value to cast. Must be non @c null.
+ * @param context the usual ReportContext, used for error reporting.
+ * @returns the new value which was the result of the cast. If the
+ * cast failed, an ValidationError is returned.
+ */
+ Item cast(const Item &sourceValue,
+ const ReportContext::Ptr &context) const;
+
+ /**
+ * This function should be called at compiled time, it attempts to determine
+ * what AtomicCaster that should be used when casting from @p sourceType to
+ * targetType(). If that is not possible, because the @p sourceType is
+ * @c xs:anyAtomicType for instance, the AtomicCaster lookup will done at
+ * runtime on a case-per-case basis.
+ *
+ * @returns @c true if the requested casting combination is valid or might be valid.
+ * If it is guranteed to be invalid, @c false is returned.
+ */
+ bool prepareCasting(const ReportContext::Ptr &context,
+ const ItemType::Ptr &sourceType);
+
+ /**
+ * Checks that the targetType() is a valid target type for <tt>castable as</tt>
+ * and <tt>cast as</tt>. For example, that it is not abstract. If the type is
+ * invalid, an error is raised via the @p context. Note that it is assumed the type
+ * is atomic.
+ */
+ void checkTargetType(const ReportContext::Ptr &context) const;
+
+ private:
+ inline Item castWithCaster(const Item &sourceValue,
+ const AtomicCaster::Ptr &caster,
+ const ReportContext::Ptr &context) const;
+
+ /**
+ * Locates the caster for casting values of type @p sourceType to targetType(), if
+ * possible.
+ *
+ * @p castImpossible is not initialized. Initialize it to @c false.
+ */
+ static AtomicCaster::Ptr locateCaster(const ItemType::Ptr &sourceType,
+ const ReportContext::Ptr &context,
+ bool &castImpossible,
+ const SourceLocationReflection *const location,
+ const ItemType::Ptr &targetType);
+ private:
+ inline Item castWithCaster(const Item &sourceValue,
+ const AtomicCaster::Ptr &caster,
+ const DynamicContext::Ptr &context) const;
+
+
+ inline ItemType::Ptr targetType() const
+ {
+ Q_ASSERT(static_cast<const TSubClass *>(this)->targetType());
+ return static_cast<const TSubClass *>(this)->targetType();
+ }
+
+ void issueCastError(const Item &validationError,
+ const Item &sourceValue,
+ const ReportContext::Ptr &context) const;
+
+ Q_DISABLE_COPY(CastingPlatform)
+ AtomicCaster::Ptr m_caster;
+ const ReportContext::ErrorCode m_errorCode;
+ };
+
+#include "qcastingplatform.cpp"
+
+}
+
+QT_END_NAMESPACE
+
+QT_END_HEADER
+
+#endif