public class AtomicSortComparer extends java.lang.Object implements AtomicComparer
Modifier and Type | Field and Description |
---|---|
static AtomicMatchKey |
COLLATION_KEY_NaN |
Modifier | Constructor and Description |
---|---|
protected |
AtomicSortComparer(StringCollator collator,
int itemType,
XPathContext context) |
Modifier and Type | Method and Description |
---|---|
int |
compareAtomicValues(AtomicValue a,
AtomicValue b)
Compare two AtomicValue objects according to the rules for their data type.
|
protected int |
compareNonComparables(AtomicValue a,
AtomicValue b)
Compare two values that are known to be non-comparable.
|
boolean |
comparesEqual(AtomicValue a,
AtomicValue b)
Compare two AtomicValue objects for equality according to the rules for their data type.
|
StringCollator |
getCollator()
Get the collation used by this AtomicComparer if any
|
int |
getItemType()
Get the requested item type
|
StringCollator |
getStringCollator()
Get the underlying StringCollator
|
static AtomicComparer |
makeSortComparer(StringCollator collator,
int itemType,
XPathContext context)
Factory method to get an atomic comparer suitable for sorting or for grouping (operations in which
NaN is considered equal to NaN)
|
AtomicComparer |
provideContext(XPathContext context)
Supply the dynamic context in case this is needed for the comparison
|
java.lang.String |
save()
Create a string representation of this AtomicComparer that can be saved in a compiled
package and used to reconstitute the AtomicComparer when the package is reloaded
|
public static AtomicMatchKey COLLATION_KEY_NaN
protected AtomicSortComparer(StringCollator collator, int itemType, XPathContext context)
public static AtomicComparer makeSortComparer(StringCollator collator, int itemType, XPathContext context)
collator
- Collating comparer to be used when comparing strings. This argument may be null
if the itemType excludes the possibility of comparing strings. If the method is called at compile
time, this should be a SimpleCollation so that it can be cloned at run-time.itemType
- the primitive item type of the values to be comparedcontext
- Dynamic context (may be an EarlyEvaluationContext)public StringCollator getCollator()
AtomicComparer
getCollator
in interface AtomicComparer
public AtomicComparer provideContext(XPathContext context)
provideContext
in interface AtomicComparer
context
- the dynamic evaluation contextpublic StringCollator getStringCollator()
public int getItemType()
public int compareAtomicValues(AtomicValue a, AtomicValue b) throws NoDynamicContextException
compareAtomicValues
in interface AtomicComparer
a
- the first object to be compared. It is intended that this should normally be an instance
of AtomicValue, though this restriction is not enforced. If it is a StringValue, the
collator is used to compare the values, otherwise the value must implement the java.util.Comparable
interface.b
- the second object to be compared. This must be comparable with the first object: for
example, if one is a string, they must both be strings.java.lang.ClassCastException
- if the objects are not comparableNoDynamicContextException
- if this comparer required access to dynamic context information,
notably the implicit timezone, and this information is not available. In general this happens if a
context-dependent comparison is attempted at compile-time, and it signals the compiler to generate
code that tries again at run-time.protected int compareNonComparables(AtomicValue a, AtomicValue b)
SequenceTool.INDETERMINATE_ORDERING
a
- the first value to be comparedb
- the second value to be comparedjava.lang.ClassCastException
- if the two values are not comparablepublic boolean comparesEqual(AtomicValue a, AtomicValue b) throws NoDynamicContextException
comparesEqual
in interface AtomicComparer
a
- the first object to be compared. It is intended that this should be an instance
of AtomicValue, though this restriction is not enforced. If it is a StringValue, the
collator is used to compare the values, otherwise the value must implement the equals() method.b
- the second object to be compared. This must be comparable with the first object: for
example, if one is a string, they must both be strings.java.lang.ClassCastException
- if the objects are not comparableNoDynamicContextException
public java.lang.String save()
save
in interface AtomicComparer
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