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39
40//
41// W A R N I N G
42// -------------
43//
44// This file is not part of the Qt API. It exists purely as an
45// implementation detail. This header file may change from version to
46// version without notice, or even be removed.
47//
48// We mean it.
49
50#ifndef Patternist_OptimizationBlocks_H
51#define Patternist_OptimizationBlocks_H
52
53#include <private/qatomiccomparator_p.h>
54#include <private/qexpression_p.h>
55#include <private/qoptimizerframework_p.h>
56
57QT_BEGIN_NAMESPACE
58
59namespace QPatternist
60{
61 /**
62 * @short Contains a set of common OptimizerPass instances.
63 *
64 * @author Frans englich <frans.englich@nokia.com>
65 * @ingroup Patternist_expressions
66 */
67 namespace OptimizationPasses
68 {
69 /**
70 * A list of OptimizerPass instances that performs the
71 * following rewrites:
72 *
73 * - <tt>count([expr]) ne 0</tt> into <tt>exists([expr])</tt>
74 * - <tt>count([expr]) != 0</tt> into <tt>exists([expr])</tt>
75 * - <tt>0 ne count([expr])</tt> into <tt>exists([expr])</tt>
76 * - <tt>0 != count([expr])</tt> into <tt>exists([expr])</tt>
77 * - <tt>count([expr]) eq 0</tt> into <tt>empty([expr])</tt>
78 * - <tt>count([expr]) = 0</tt> into <tt>empty([expr])</tt>
79 * - <tt>0 eq count([expr])</tt> into <tt>empty([expr])</tt>
80 * - <tt>0 = count([expr])</tt> into <tt>empty([expr])</tt>
81 * - <tt>count([expr]) ge 1</tt> into <tt>exists([expr])</tt>
82 * - <tt>count([expr]) >= 1</tt> into <tt>exists([expr])</tt>
83 */
84 extern OptimizationPass::List comparisonPasses;
85
86 /**
87 * A list of OptimizerPass instances that performs the
88 * following rewrites:
89 *
90 * - <tt>for $var in [expr] return $var</tt> into <tt>[expr]</tt>
91 */
92 extern OptimizationPass::List forPasses;
93
94 /**
95 * A list of OptimizerPass instances that performs the
96 * following rewrites:
97 *
98 * - <tt>if([expr of type xs:boolean]) then true() else false()</tt>
99 * into <tt>[expr of type xs:boolean]</tt>
100 */
101 extern OptimizationPass::List ifThenPasses;
102
103 /**
104 * A list of OptimizerPass instances that performs the
105 * following rewrites:
106 *
107 * - <tt>fn:not(fn:exists([expr]))</tt> into <tt>fn:empty([expr])</tt>
108 * - <tt>fn:not(fn:empty([expr]))</tt> into <tt>fn:exists([expr])</tt>
109 */
110 extern OptimizationPass::List notFN;
111
112 /**
113 * Initializes the data members in the OptimizationPasses namespace.
114 *
115 * This class is not supposed to be instantiated, but to be used via its init()
116 * function. In fact, this class cannot be instantiated.
117 *
118 * @author Frans englich <frans.englich@nokia.com>
119 */
120 class Coordinator
121 {
122 public:
123 /**
124 * Initializes the members in the OptimizationPasses namespace.
125 */
126 static void init();
127
128 private:
129 Q_DISABLE_COPY(Coordinator)
130 inline Coordinator();
131 };
132 }
133}
134
135QT_END_NAMESPACE
136
137#endif
138

source code of qtxmlpatterns/src/xmlpatterns/expr/qoptimizationpasses_p.h