Package net.sf.saxon.sort
Class DoubleSortComparer
java.lang.Object
net.sf.saxon.sort.DoubleSortComparer
- All Implemented Interfaces:
Serializable
,Comparator
,AtomicComparer
A Comparator used for sorting values that are known to be numeric.
It also supports a separate method for getting a collation key to test equality of items.
This comparator treats NaN values as equal to each other, and less than any other value.
- Author:
- Michael H. Kay
- See Also:
-
Method Summary
Modifier and TypeMethodDescriptionint
Compare two AtomicValue objects according to the rules for their data type.boolean
Test whether two values compare equal.Get a comparison key for an object.static DoubleSortComparer
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
Methods inherited from interface java.util.Comparator
equals, reversed, thenComparing, thenComparing, thenComparing, thenComparingDouble, thenComparingInt, thenComparingLong
-
Method Details
-
getInstance
-
compare
Compare two AtomicValue objects according to the rules for their data type.- Specified by:
compare
in interfaceAtomicComparer
- Specified by:
compare
in interfaceComparator
- Parameters:
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.- Returns:
- invalid input: '<'0 if ainvalid input: '<'b, 0 if a=b, >0 if a>b
- Throws:
ClassCastException
- if the objects are not comparable
-
comparesEqual
Test whether two values compare equal. Note that for this comparer, NaN is considered equal to itself- Specified by:
comparesEqual
in interfaceAtomicComparer
- Parameters:
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.- Returns:
- true if the values are equal, false if not
-
getComparisonKey
Get a comparison key for an object. This must satisfy the rule that if two objects are equal as defined by the XPath eq operator, then their comparison keys are equal as defined by the Java equals() method, and vice versa. There is no requirement that the comparison keys should reflect the ordering of the underlying objects.- Specified by:
getComparisonKey
in interfaceAtomicComparer
-