Package net.sf.saxon.expr.sort

Class CollatingAtomicComparer

java.lang.Object
net.sf.saxon.expr.sort.CollatingAtomicComparer
All Implemented Interfaces:
AtomicComparer
public class CollatingAtomicComparer extends Object implements AtomicComparer
An AtomicComparer used for comparing strings, untypedAtomic values, and URIs using a collation. A CollatingAtomicComparer is used when it is known in advance that both operands will be of these types. This enables all conversions and promotions to be bypassed: the string values of both operands are simply extracted and passed to the collator for comparison.

  • Constructor Details

    • CollatingAtomicComparer

      public CollatingAtomicComparer(StringCollator collator)
      Create an GenericAtomicComparer
      Parameters:
      collator - the collation to be used. If the method is called at compile time, this should be a SimpleCollation so that it can be cloned at run-time.

  • Method Details

    • getCollator

      public StringCollator getCollator()
      Description copied from interface: AtomicComparer
      Get the collation used by this AtomicComparer if any
      Specified by:
      getCollator in interface AtomicComparer
      Returns:
      the collation used for comparing strings, or null if not applicable

    • provideContext

      public AtomicComparer provideContext(XPathContext context)
      Supply the dynamic context in case this is needed for the comparison
      Specified by:
      provideContext in interface AtomicComparer
      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

    • compareAtomicValues

      public int compareAtomicValues(AtomicValue a, AtomicValue 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:
      compareAtomicValues in interface AtomicComparer
      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 a<b, 0 if a=b, >0 if a>b
      Throws:
      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 interface AtomicComparer
      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
      Throws:
      ClassCastException - if the objects are not comparable

    • save

      public 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
      Specified by:
      save in interface AtomicComparer
      Returns:
      a string representation of the AtomicComparer

    • hashCode

      public int hashCode()
      Overrides:
      hashCode in class Object

    • equals

      public boolean equals(Object obj)
      Overrides:
      equals in class Object