Package net.sf.saxon.sort
Class TextComparer
java.lang.Object
net.sf.saxon.sort.TextComparer
- All Implemented Interfaces:
Serializable
,AtomicComparer
A Comparer used for comparing sort keys when data-type="text". The items to be
compared are converted to strings, and the strings are then compared using an
underlying collator
- Author:
- Michael H. Kay
- See Also:
-
Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionint
Compare two Items by converting them to strings and comparing the string values.boolean
Compare two AtomicValue objects for equality according to the rules for their data type.Get the underlying comparer (which doesn't do conversion to string)Get a comparison key for an object.provideContext
(XPathContext context) Supply the dynamic context in case this is needed for the comparison
-
Constructor Details
-
TextComparer
-
-
Method Details
-
getBaseComparer
Get the underlying comparer (which doesn't do conversion to string) -
provideContext
Supply the dynamic context in case this is needed for the comparison- Specified by:
provideContext
in interfaceAtomicComparer
- Parameters:
context
- the dynamic evaluation context- Returns:
- either the original AtomicComparer, or a new AtomicComparer in which the context is known. The original AtomicComparer is not modified
- Throws:
NoDynamicContextException
- if the context is an "early evaluation" (compile-time) context
-
compareAtomicValues
public int compareAtomicValues(AtomicValue a, AtomicValue b) throws ClassCastException, NoDynamicContextException Compare two Items by converting them to strings and comparing the string values.- Specified by:
compareAtomicValues
in interfaceAtomicComparer
- Parameters:
a
- the first Item to be compared.b
- the second Item to be compared.- Returns:
- invalid input: '<'0 if ainvalid input: '<'b, 0 if a=b, >0 if a>b
- Throws:
ClassCastException
- if the objects are not Items, or are items that cannot be convered to strings (e.g. QNames)NoDynamicContextException
- 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.
-
comparesEqual
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.b
- the second object to be compared.- Returns:
- true if the values are equal, false if not
- Throws:
ClassCastException
- if the objects are not comparableNoDynamicContextException
-
getComparisonKey
Get a comparison key for an object. This must satisfy the rule that if two objects are equal according to the XPath eq operator, then their comparison keys are equal according to 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
- Throws:
NoDynamicContextException
-