Package net.sf.saxon.sort
Class GenericAtomicComparer
- java.lang.Object
-
- net.sf.saxon.sort.GenericAtomicComparer
-
- All Implemented Interfaces:
java.io.Serializable
,java.util.Comparator
,AtomicComparer
public class GenericAtomicComparer extends java.lang.Object implements AtomicComparer, java.util.Comparator, java.io.Serializable
A Comparator used for comparing atomic values of arbitrary item types. It encapsulates a Collator that is used when the values to be compared are strings. It also supports a separate method for testing equality of items, which can be used for data types that are not ordered.- Author:
- Michael H. Kay
- See Also:
- Serialized Form
-
-
Constructor Summary
Constructors Constructor Description GenericAtomicComparer(java.util.Comparator collator, Configuration config)
GenericAtomicComparer(java.util.Comparator collator, XPathContext conversion)
Create an GenericAtomicComparer
-
Method Summary
All Methods Static Methods Instance Methods Concrete Methods Modifier and Type Method Description int
compare(java.lang.Object a, java.lang.Object b)
Compare two AtomicValue objects according to the rules for their data type.boolean
comparesEqual(AtomicValue a, AtomicValue b)
Compare two AtomicValue objects for equality according to the rules for their data type.ComparisonKey
getComparisonKey(AtomicValue a)
Get a comparison key for an object.static AtomicComparer
makeAtomicComparer(int type0, int type1, java.util.Comparator collator, Configuration config)
Factory method to make a GenericAtomicComparer for values of known types
-
-
-
Constructor Detail
-
GenericAtomicComparer
public GenericAtomicComparer(java.util.Comparator collator, XPathContext conversion)
Create an GenericAtomicComparer- Parameters:
collator
- the collation to be usedconversion
- a context, used when converting untyped atomic values to the target type.
-
GenericAtomicComparer
public GenericAtomicComparer(java.util.Comparator collator, Configuration config)
-
-
Method Detail
-
makeAtomicComparer
public static AtomicComparer makeAtomicComparer(int type0, int type1, java.util.Comparator collator, Configuration config)
Factory method to make a GenericAtomicComparer for values of known types- Parameters:
type0
- primitive type of the first operandtype1
- primitive type of the second operandcollator
- the collation to be used, if anyconfig
- the configuration- Returns:
- a GenericAtomicComparer for values of known types
-
compare
public int compare(java.lang.Object a, java.lang.Object b)
Compare two AtomicValue objects according to the rules for their data type. UntypedAtomic values are compared as if they were strings; if different semantics are wanted, the conversion must be done by the caller.- Specified by:
compare
in interfaceAtomicComparer
- Specified by:
compare
in interfacejava.util.Comparator
- 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 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:
- <0 if a0 if a>b
- Throws:
java.lang.ClassCastException
- if the objects are not comparable
-
comparesEqual
public boolean comparesEqual(AtomicValue a, AtomicValue b)
Compare two AtomicValue objects for equality according to the rules for their data type. UntypedAtomic values are compared by converting to the type of the other operand.- 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:
- <0 if a0 if a>b
- Throws:
java.lang.ClassCastException
- if the objects are not comparable
-
getComparisonKey
public ComparisonKey getComparisonKey(AtomicValue a)
Get a comparison key for an object. This must satisfy the rule that if two objects are equal, then their comparison keys are equal, and vice versa. There is no requirement that the comparison keys should reflect the ordering of the underlying objects.- Specified by:
getComparisonKey
in interfaceAtomicComparer
-
-