Package net.sf.saxon.expr.sort

Class TextComparer

java.lang.Object
net.sf.saxon.expr.sort.TextComparer
All Implemented Interfaces:
AtomicComparer
public class TextComparer extends Object implements 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

  • Constructor Details

  • Method Details

    • getBaseComparer

      public AtomicComparer getBaseComparer()
      Get the underlying comparer (which doesn't do conversion to string)
      Returns:
      the underlying comparer

    • 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) throws ClassCastException, NoDynamicContextException
      Compare two Items by converting them to strings and comparing the string values.
      Specified by:
      compareAtomicValues in interface AtomicComparer
      Parameters:
      a - the first Item to be compared.
      b - the second Item to be compared.
      Returns:
      <0 if a<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

      public boolean comparesEqual(AtomicValue a, AtomicValue b) throws NoDynamicContextException
      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.
      b - the second object to be compared.
      Returns:
      true if the values are equal, false if not
      Throws:
      ClassCastException - if the objects are not comparable
      NoDynamicContextException - if no dynamic context has been supplied, and a dynamic context is needed (for example, because the comparison uses the implicit timezone)

    • 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