net.sf.saxon.value
Class IntegerRange

java.lang.Object
  extended by net.sf.saxon.value.Value
      extended by net.sf.saxon.value.IntegerRange
All Implemented Interfaces:
Serializable, SequenceIterable, GroundedValue, ValueRepresentation

public class IntegerRange
extends Value
implements GroundedValue

This class represents a sequence of consecutive ascending integers, for example 1 to 50. The integers must be within the range of a Java long.

See Also:
Serialized Form

Field Summary
 long end
           
 long start
           
 
Fields inherited from class net.sf.saxon.value.Value
EMPTY_CLASS_ARRAY, INDETERMINATE_ORDERING
 
Fields inherited from interface net.sf.saxon.om.ValueRepresentation
EMPTY_VALUE_ARRAY
 
Constructor Summary
IntegerRange(long start, long end)
          Construct an integer range expression
 
Method Summary
 int getCardinality()
          Determine the cardinality
 long getEnd()
          Get the last integer in the sequence (inclusive)
 ItemType getItemType(TypeHierarchy th)
          Determine the data type of the items in the expression, if possible
 int getLength()
          Get the length of the sequence
 long getStart()
          Get the first integer in the sequence (inclusive)
 Item itemAt(int n)
          Get the n'th item in the sequence (starting from 0).
 SequenceIterator iterate()
          Return an Iterator to iterate over the values of a sequence.
 GroundedValue subsequence(int start, int length)
          Get a subsequence of the value
 
Methods inherited from class net.sf.saxon.value.Value
asItem, asItem, asIterator, asValue, checkPermittedContents, convertJavaObjectToXPath, convertToJava, convertToJava, effectiveBooleanValue, equals, fromItem, getCanonicalLexicalRepresentation, getIterator, getSchemaComparable, getStringValue, getStringValueCS, iterate, makeQNameValue, process, reduce, stringToNumber, toString
 
Methods inherited from class java.lang.Object
getClass, hashCode, notify, notifyAll, wait, wait, wait
 
Methods inherited from interface net.sf.saxon.om.ValueRepresentation
getStringValue, getStringValueCS
 

Field Detail

start

public long start

end

public long end
Constructor Detail

IntegerRange

public IntegerRange(long start,
                    long end)
Construct an integer range expression

Parameters:
start - the first integer in the sequence (inclusive)
end - the last integer in the sequence (inclusive). Must be >= start
Method Detail

getStart

public long getStart()
Get the first integer in the sequence (inclusive)

Returns:
the first integer in the sequence (inclusive)

getEnd

public long getEnd()
Get the last integer in the sequence (inclusive)

Returns:
the last integer in the sequence (inclusive)

iterate

public SequenceIterator iterate()
                         throws XPathException
Return an Iterator to iterate over the values of a sequence. The value of every expression can be regarded as a sequence, so this method is supported for all expressions. This default implementation handles iteration for expressions that return singleton values: for non-singleton expressions, the subclass must provide its own implementation.

Specified by:
iterate in class Value
Returns:
a SequenceIterator that can be used to iterate over the result of the expression
Throws:
XPathException - if any dynamic error occurs evaluating the expression

getItemType

public ItemType getItemType(TypeHierarchy th)
Determine the data type of the items in the expression, if possible

Overrides:
getItemType in class Value
Parameters:
th - the type hierarchy cache
Returns:
AnyItemType (not known)

getCardinality

public int getCardinality()
Determine the cardinality

Overrides:
getCardinality in class Value
Returns:
the cardinality

itemAt

public Item itemAt(int n)
Get the n'th item in the sequence (starting from 0). This is defined for all Values, but its real benefits come for a sequence Value stored extensionally (or for a MemoClosure, once all the values have been read)

Specified by:
itemAt in interface GroundedValue
Overrides:
itemAt in class Value
Parameters:
n - position of the required item, counting from zero.
Returns:
the n'th item in the sequence, where the first item in the sequence is numbered zero. If n is negative or >= the length of the sequence, returns null.

subsequence

public GroundedValue subsequence(int start,
                                 int length)
Get a subsequence of the value

Specified by:
subsequence in interface GroundedValue
Parameters:
start - the index of the first item to be included in the result, counting from zero. A negative value is taken as zero. If the value is beyond the end of the sequence, an empty sequence is returned
length - the number of items to be included in the result. Specify Integer.MAX_VALUE to get the subsequence up to the end of the base sequence. If the value is negative, an empty sequence is returned. If the value goes off the end of the sequence, the result returns items up to the end of the sequence
Returns:
the required subsequence.

getLength

public int getLength()
              throws XPathException
Get the length of the sequence

Overrides:
getLength in class Value
Returns:
the number of items in the sequence
Throws:
XPathException


Copyright (C) Michael H. Kay. All rights reserved.