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An OSGi bundle for Saxon-HE
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// Copyright (c) 2013 Saxonica Limited.
// This Source Code Form is subject to the terms of the Mozilla Public License, v. 2.0.
// If a copy of the MPL was not distributed with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
// This Source Code Form is "Incompatible With Secondary Licenses", as defined by the Mozilla Public License, v. 2.0.
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
package net.sf.saxon.value;
import net.sf.saxon.expr.RangeIterator;
import net.sf.saxon.expr.StaticProperty;
import net.sf.saxon.expr.parser.ExpressionTool;
import net.sf.saxon.om.*;
import net.sf.saxon.trans.XPathException;
import net.sf.saxon.type.BuiltInAtomicType;
import net.sf.saxon.type.ItemType;
import net.sf.saxon.type.TypeHierarchy;
/**
* 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.
*/
public class IntegerRange implements AtomicSequence, GroundedValue {
public long start;
public long end;
/**
* Construct an integer range expression
* @param start the first integer in the sequence (inclusive)
* @param end the last integer in the sequence (inclusive). Must be >= start
*/
public IntegerRange(long start, long end) {
if (end < start) {
throw new IllegalArgumentException("end < start in IntegerRange");
}
if (end - start > Integer.MAX_VALUE) {
throw new IllegalArgumentException("Maximum length of sequence in Saxon is " + Integer.MAX_VALUE);
}
this.start = start;
this.end = end;
}
/**
* Get the first integer in the sequence (inclusive)
* @return the first integer in the sequence (inclusive)
*/
public long getStart() {
return start;
}
/**
* Get the last integer in the sequence (inclusive)
* @return the last integer in the sequence (inclusive)
*/
public long getEnd() {
return end;
}
/**
* 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.
*
* @return a SequenceIterator that can be used to iterate over the result
* of the expression
* @throws net.sf.saxon.trans.XPathException
* if any dynamic error occurs evaluating the
* expression
*/
/*@NotNull*/ public SequenceIterator iterate() {
try {
return new RangeIterator(start, end);
} catch (XPathException e) {
throw new AssertionError(e);
}
}
/**
* Determine the data type of the items in the expression, if possible
*
* @return AnyItemType (not known)
* @param th the type hierarchy cache
*/
/*@NotNull*/ public ItemType getItemType(TypeHierarchy th) {
return BuiltInAtomicType.INTEGER;
}
/**
* Determine the cardinality
*/
public int getCardinality() {
return StaticProperty.ALLOWS_MANY;
}
/**
* 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)
*/
/*@Nullable*/ public IntegerValue itemAt(int n) {
if (n < 0 || n > (end-start)) {
return null;
}
return Int64Value.makeIntegerValue(start + n);
}
/**
* Get a subsequence of the value
*
*
* @param 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
* @param 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
* @return the required subsequence.
*/
/*@NotNull*/ public GroundedValue subsequence(int start, int length) {
if (length <= 0) {
return EmptySequence.getInstance();
}
long newStart = this.start + (start > 0 ? start : 0);
long newEnd = newStart + length - 1;
if (newEnd > end) {
newEnd = end;
}
if (newEnd >= newStart) {
return new IntegerRange(newStart, newEnd);
} else {
return EmptySequence.getInstance();
}
}
/**
* Get the length of the sequence
*/
public int getLength() {
return (int)(end - start + 1);
}
public AtomicValue head() {
return new Int64Value(start);
}
/**
* Get the canonical lexical representation as defined in XML Schema. This is not always the same
* as the result of casting to a string according to the XPath rules.
*
* @return the canonical lexical representation if defined in XML Schema; otherwise, the result
* of casting to string according to the XPath 2.0 rules
*/
public CharSequence getCanonicalLexicalRepresentation() {
return getStringValueCS();
}
/**
* Get a Comparable value that implements the XML Schema ordering comparison semantics for this value.
* The default implementation is written to compare sequences of atomic values.
* This method is overridden for AtomicValue and its subclasses.
*
* In the case of data types that are partially ordered, the returned Comparable extends the standard
* semantics of the compareTo() method by returning the value {@link net.sf.saxon.om.SequenceTool#INDETERMINATE_ORDERING} when there
* is no defined order relationship between two given values.
*
* @return a Comparable that follows XML Schema comparison rules
*/
public Comparable getSchemaComparable() {
try {
return new AtomicArray(iterate()).getSchemaComparable();
} catch (XPathException err) {
throw new AssertionError(err);
}
}
public CharSequence getStringValueCS() {
try {
return SequenceTool.getStringValue(this);
} catch (XPathException err) {
throw new AssertionError(err);
}
}
public String getStringValue() {
return getStringValueCS().toString();
}
public boolean effectiveBooleanValue() throws XPathException {
return ExpressionTool.effectiveBooleanValue(iterate());
}
/**
* Reduce the sequence to its simplest form. If the value is an empty sequence, the result will be
* EmptySequence.getInstance(). If the value is a single atomic value, the result will be an instance
* of AtomicValue. If the value is a single item of any other kind, the result will be an instance
* of SingletonItem. Otherwise, the result will typically be unchanged.
*
* @return the simplified sequence
*/
public GroundedValue reduce() {
if (start == end) {
return itemAt(0);
} else {
return this;
}
}
}
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