Package net.sf.saxon.expr.sort

This package provides utility routines for sorting and grouping. Specifically, it contains a QuickSort implementation, and some AtomicComparer objects that handle character and numeric comparisons, together with the important DocumentOrderIterator which iterates over a set of nodes in document order.

The package also contains the classes to support the implementation of the XSLT 2.0 instruction xsl:for-each-group, and some utilities for maintaining sets and maps whose keys are unboxed integer values.

Interface Summary

Interface	Description
AtomicComparer	Interface representing an object that can be used to compare two XPath atomic values for equality or for ordering.
AtomicMatchKey	Marker interface to identify an object that acts as a surrogate for an atomic value, with the property that if two atomic values are equal under the XPath 'eq' operator, then their corresponding surrogates are equal under the Java equals() comparison (and by implication, they have equal hash codes).
EqualityMatcher<T>	Interface representing objects used to perform equality matching.
GenericAtomicComparer.AtomicComparisonFunction	An AtomicComparisonFunction compares two atomic values to return a result of true or false.
GroupIterator	A GroupIterator is an iterator that iterates over a sequence of groups.
SortKeyEvaluator	Callback interface used to evaluate sort keys.
XPathComparable	This interface sometimes represents an XPath atomic value where the Java comparison semantics (using the compareTo method) match the XPath equality and ordering semantics; and sometimes it represents a surrogate for an XPath atomic value, chosen so that the Java comparison semantics match the XPath rules.

Class Summary

Class	Description
AlphanumericCollator	A Comparer that treats strings as an alternating sequence of alpha parts and numeric parts.
AtomicSortComparer	An AtomicComparer used for comparing atomic values of arbitrary item types.
CalendarValueComparer	A comparer specifically for comparing two date, time, or dateTime values
CaseFirstCollator	A StringCollator that sorts lowercase before uppercase, or vice versa.
CodepointCollatingComparer	An AtomicComparer used for comparing strings, untypedAtomic values, and URIs using the Unicode codepoint collation.
CodepointCollator	A collating sequence that uses Unicode codepoint ordering
CollatingAtomicComparer	An AtomicComparer used for comparing strings, untypedAtomic values, and URIs using a collation.
CollationMatchKey	A match key for comparing strings under a collation.
CompositeAtomicKey	A composite atomic key is a sequence of atomic values; two such keys are matched be comparing the constituent values pairwise.
ConditionalSorter	An expression that sorts an underlying sequence into document order if some condition is true, or that returns the sequence "as is" (knowing that it doesn't need sorting) if the condition is false.
ConditionalSorter.ConditionalSorterElaborator	Elaborator for a conditional sorter, which sorts the results of a subexpression into document order only if a supplied condition is true
ContextFreeAtomicComparer	A comparer for comparing two "ordinary" atomic values, where the values implement the Comparable interface and the equals() method with the appropriate XPath semantics.
CustomMap<K,V>	A map implementation using a custom equality matcher, to avoid having to wrap each entry in a wrapper object to achieve customised equality testing.
CustomSet<T>	A mutable set implementation using a custom equality matcher, to avoid having to wrap each entry in a wrapper object to achieve customised equality testing.
DecimalSortComparer	An AtomicComparer used for sorting values that are known to be instances of xs:decimal (including xs:integer), It also supports a separate method for getting a collation key to test equality of items
DescendingComparer	A Comparer used for comparing descending keys.
DocumentOrderIterator	DocumentOrderIterator takes as input an iteration of nodes in any order, and returns as output an iteration of the same nodes in document order, eliminating any duplicates.
DocumentSorter	A DocumentSorter is an expression that sorts a sequence of nodes into document order.
DocumentSorter.DocumentSorterElaborator	Elaborator for a docOrder expression - sorts nodes into document order and eliminates duplicates
DoubleSortComparer	An AtomicComparer used for sorting values that are known to be numeric.
EmptyGreatestComparer	A Comparer that modifies a base comparer by sorting empty key values and NaN values last (greatest), as opposed to the default which sorts them first.
EmptyIntIterator	An iterator over a zero-length sequence of integers
EqualityComparer	A comparer for comparing two atomic values where (a) equals is defined, and is implemented using the Java equals() method, and (b) ordering is not defined, and results in a dynamic error.
GenericAtomicComparer	An AtomicComparer used for comparing atomic values of arbitrary item types.
GlobalOrderComparer	A Comparer used for comparing nodes in document order.
GroupAdjacentIterator	A GroupAdjacentIterator iterates over a sequence of groups defined by xsl:for-each-group group-adjacent="x".
GroupBreakingIterator	A GroupBreakingIterator iterates over a sequence of groups defined by xsl:for-each-group break-when="x".
GroupByIterator	A GroupByIterator iterates over a sequence of groups defined by xsl:for-each-group group-by="x".
GroupEndingIterator	A GroupEndingIterator iterates over a sequence of groups defined by xsl:for-each-group group-ending-with="x".
GroupMatchingIterator	A GroupMatchingIterator contains code shared between GroupStartingIterator and GroupEndingIterator
GroupStartingIterator	A GroupStartingIterator iterates over a sequence of groups defined by xsl:for-each-group group-starting-with="x".
GroupToBeSorted	This class is a specialization of ObjectToBeSorted for use when the sequence being sorted is a sequence of groups.
HTML5CaseBlindCollator	A collating sequence that compares strings according to the HTML5 rules for case-blind matching.
ItemToBeSorted	This class is a specialization of class ObjectToBeSorted for use when the sequence being sorted is a sequence of items (including tuples, which are represented as items).
ItemWithMergeKeys	A class representing an item together with its merge keys and the name of the merge source object from which it derived, suitable for encapsulation as an ObjectValue.
LFUCache<K,V>	A "Least Frequently Used" cache.
LocalOrderComparer	A Comparer used for comparing nodes in document order.
MergeGroupingIterator	An iterator that groups the result of merging several xsl:merge input streams, identifying groups of adjacent items having the same merge key value
MergeInstr
MergeInstr.MergeKeyMappingFunction	Mapping function for items encountered during the merge; the mapping function wraps the merged item and its merge keys into a single composite object
MergeInstr.MergeSource	Inner class representing one merge source
MergeIterator	An iterator representing the sorted merge of two merge inputs, retaining all duplicates.
NumericComparer	A Comparer used for comparing sort keys when data-type="number".
NumericComparer11	A Comparer used for comparing sort keys when data-type="number".
ObjectToBeSorted	This class represents a member of a sequence that is being sorted.
RuleBasedSubstringMatcher	This class wraps a RuleBasedCollator to provide a SubstringMatcher.
SimpleCollation	A simple collation that just wraps a supplied Comparator
SimpleTypeComparison	This class implements equality and ordering comparisons between values of simple types: that is, atomic values, and sequences of atomic values, following the XSD-defined rules for equality and ordering comparisons.
SimpleTypeIdentityComparison	This class implements equality and identity comparisons between values of simple types: that is, atomic values, and sequences of atomic values, following the XSD-defined rules for equality and identity comparisons.
SortedGroupIterator	A SortedGroupIterator is a modified SortedIterator.
SortedIterator	Class to do a sorted iteration
SortExpression	Expression equivalent to the imaginary syntax expr sortby (sort-key)+
SortExpression.SortExprElaborator	Elaborator for a sort expression - sorts nodes into order based on a user-supplied sort key
SortKeyDefinition	A SortKeyDefinition defines one component of a sort key.
SortKeyDefinitionList	The class represents a list of sort key definitions in major-to-minor sort key order.
TextComparer	A Comparer used for comparing sort keys when data-type="text".
UcaCollatorUsingJava	This class implements (an approximation to) the UCA Collation Algorithm relying solely on the built-in Java support (that is, without using the ICU library).
UntypedNumericComparer	A specialist comparer that implements the rules for comparing an untypedAtomic value (always the first operand) to a numeric value (always the second operand)

Exception Summary

Exception	Description
ComparisonException	A ComparisonException is a ClassCastException that encapsulates an XPathException.