Class AtomicValue
- All Implemented Interfaces:
Iterable<AtomicValue>
,AtomicSequence
,GroundedValue
,IdentityComparable
,Item
,Sequence
,ConversionResult
- Direct Known Subclasses:
Base64BinaryValue
,BooleanValue
,CalendarValue
,DurationValue
,HexBinaryValue
,NestedIntegerValue
,NumericValue
,QualifiedNameValue
,StringValue
The AtomicValue class contains some methods that are suitable for applications to use, and many others that are designed for internal use by Saxon itself. These have not been fully classified. At present, therefore, none of the methods on this class should be considered to be part of the public Saxon API.
- Author:
- Michael H. Kay
-
Field Summary
Fields -
Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionasAtomic()
Calling this method on a ConversionResult returns the AtomicValue that results from the conversion if the conversion was successful, and throws a ValidationException explaining the conversion error otherwise.asMapKey()
Get a value whose equals() method follows the "same key" rules for comparing the keys of a map.atomize()
Atomize the item.void
checkPermittedContents
(SchemaType parentType, StaticContext env, boolean whole) Check statically that the results of the expression are capable of constructing the content of a given schema type.void
Check that the value can be handled in Saxon-JSabstract AtomicValue
copyAsSubType
(AtomicType typeLabel) Create a copy of this atomic value, with a different type labelboolean
Get the effective boolean value of the valueabstract boolean
The equals() methods on atomic values is defined to follow the semantics of eq when applied to two atomic values.Get the canonical lexical representation as defined in XML Schema.final int
Determine the static cardinalitygetComponent
(AccessorFn.Component component) Method to extract components of a value.final Genre
getGenre()
Get the genre of this itemfinal AtomicType
Determine the data type of the valueint
Get the length of the sequenceprotected abstract CharSequence
Convert the value to a string, using the serialization rules for the primitive type.abstract BuiltInAtomicType
Determine the primitive type of the value.abstract Comparable
Get a Comparable value that implements the XML Schema ordering comparison semantics for this value.final String
Convert the value to a string, using the serialization rules.Get the value of the item as a CharSequence.final UType
getUType()
Determine the UType of the value.abstract AtomicMatchKey
getXPathComparable
(boolean ordered, StringCollator collator, int implicitTimezone) Get an object value that implements the XPath equality and ordering comparison semantics for this value.final AtomicValue
head()
To implementSequence
, this method returns the item itselfint
Get a hashCode that offers the guarantee that if A.isIdentical(B), then A.identityHashCode() == B.identityHashCode()boolean
isIdentical
(IdentityComparable other) Determine whether two IdentityComparable objects are identical.boolean
Determine whether two atomic values are identical, as determined by XML Schema rules.boolean
isNaN()
Test whether the value is the special value NaNfinal AtomicValue
itemAt
(int n) Get the n'th item in the sequence (starting from 0).SingleAtomicIterator<? extends AtomicValue>
iterate()
Get an iterator over all the items in the sequenceiterator()
Returns a Java iterator over the atomic sequence.void
setTypeLabel
(AtomicType type) Set the type label on this atomic value.toString()
Get string value.Methods inherited from class java.lang.Object
clone, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
Methods inherited from interface net.sf.saxon.om.GroundedValue
asIterable, concatenate, containsNode, materialize
Methods inherited from interface net.sf.saxon.om.Item
isStreamed, reduce, subsequence, toShortString
Methods inherited from interface java.lang.Iterable
forEach, spliterator
Methods inherited from interface net.sf.saxon.om.Sequence
makeRepeatable
-
Field Details
-
typeLabel
-
-
Constructor Details
-
AtomicValue
public AtomicValue()
-
-
Method Details
-
atomize
Atomize the item.- Specified by:
atomize
in interfaceItem
- Returns:
- the result of atomization
- Throws:
XPathException
- if atomization is not allowed for this kind of item
-
head
To implementSequence
, this method returns the item itself- Specified by:
head
in interfaceAtomicSequence
- Specified by:
head
in interfaceGroundedValue
- Specified by:
head
in interfaceItem
- Specified by:
head
in interfaceSequence
- Returns:
- this item
-
getLength
public int getLength()Get the length of the sequence- Specified by:
getLength
in interfaceAtomicSequence
- Specified by:
getLength
in interfaceGroundedValue
- Specified by:
getLength
in interfaceItem
- Returns:
- the number of items in the sequence (always one)
-
setTypeLabel
Set the type label on this atomic value. Note that this modifies the value, so it must only called if the caller is confident that the value is not shared. In other cases, usecopyAsSubType(net.sf.saxon.type.AtomicType)
- Parameters:
type
- the type label to be set
-
getSchemaComparable
Get a Comparable value that implements the XML Schema ordering comparison semantics for this value. An implementation must be provided for all atomic types.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
SequenceTool.INDETERMINATE_ORDERING
when there is no defined order relationship between two given values. This value is also returned when two values of different types are compared.- Specified by:
getSchemaComparable
in interfaceAtomicSequence
- Returns:
- a Comparable that follows XML Schema comparison rules
-
getXPathComparable
public abstract AtomicMatchKey getXPathComparable(boolean ordered, StringCollator collator, int implicitTimezone) throws NoDynamicContextException Get an object value that implements the XPath equality and ordering comparison semantics for this value. If the ordered parameter is set to true, the result will be a Comparable and will support a compareTo() method with the semantics of the XPath lt/gt operator, provided that the other operand is also obtained using the getXPathComparable() method. In all cases the result will support equals() and hashCode() methods that support the semantics of the XPath eq operator, again provided that the other operand is also obtained using the getXPathComparable() method. A collation is supplied for comparing strings, and an implicit timezone for comparing date/time values that have no saved timezone.- Parameters:
ordered
- true if an ordered comparison is required. In this case the result is null if the type is unordered; in other cases the returned value will be a Comparable.collator
- the collation to be used when comparing stringsimplicitTimezone
- the implicit timezone in the dynamic context, used when comparing dates/times with and without timezone- Returns:
- an Object whose equals() and hashCode() methods implement the XPath comparison semantics with respect to this atomic value. If ordered is specified, the result will either be null if no ordering is defined, or will be a Comparable
- Throws:
NoDynamicContextException
- if the supplied implicit timezone is "NO_TIMEZONE" (meaning unknown), and the implicit timezone is actually required because the value in question is a date/time value with no timezone. This can cause a failure to evaluate expressions statically (because the implicit timezone is not known statically), and it will then be caught, meaning that the expression has to be evaluated dynamically.
-
asMapKey
Get a value whose equals() method follows the "same key" rules for comparing the keys of a map.- Returns:
- a value with the property that the equals() and hashCode() methods follow the rules for comparing keys in maps.
-
equals
The equals() methods on atomic values is defined to follow the semantics of eq when applied to two atomic values. When the other operand is not an atomic value, the result is undefined (may be false, may be an exception). When the other operand is an atomic value that cannot be compared with this one, the method must throw a ClassCastException.The hashCode() method is consistent with equals().
-
isIdentical
Determine whether two atomic values are identical, as determined by XML Schema rules. This is a stronger test than equality (even schema-equality); for example two dateTime values are not identical unless they are in the same timezone.Note that even this check ignores the type annotation of the value. The integer 3 and the short 3 are considered identical, even though they are not fully interchangeable. "Identical" means the same point in the value space, regardless of type annotation.
NaN is identical to itself.
- Parameters:
v
- the other value to be compared with this one- Returns:
- true if the two values are identical, false otherwise.
-
isIdentical
Determine whether two IdentityComparable objects are identical. This is a stronger test than equality (even schema-equality); for example two dateTime values are not identical unless they are in the same timezone.- Specified by:
isIdentical
in interfaceIdentityComparable
- Parameters:
other
- the value to be compared- Returns:
- true if the two values are identical, false otherwise
-
identityHashCode
public int identityHashCode()Get a hashCode that offers the guarantee that if A.isIdentical(B), then A.identityHashCode() == B.identityHashCode()- Specified by:
identityHashCode
in interfaceIdentityComparable
- Returns:
- a hashCode suitable for use when testing for identity.
-
getStringValueCS
Get the value of the item as a CharSequence. This is in some cases more efficient than the version of the method that returns a String.- Specified by:
getStringValueCS
in interfaceAtomicSequence
- Specified by:
getStringValueCS
in interfaceGroundedValue
- Specified by:
getStringValueCS
in interfaceItem
- Returns:
- the string value of the item
- See Also:
-
getCanonicalLexicalRepresentation
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.- Specified by:
getCanonicalLexicalRepresentation
in interfaceAtomicSequence
- Returns:
- the canonical lexical representation if defined in XML Schema; otherwise, the result of casting to string according to the XPath 2.0 rules
-
itemAt
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 interfaceAtomicSequence
- Specified by:
itemAt
in interfaceGroundedValue
- Specified by:
itemAt
in interfaceItem
- 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.
-
getItemType
Determine the data type of the value- Returns:
- the type annotation of the atomic value
-
getPrimitiveType
Determine the primitive type of the value. This delivers the same answer as getItemType().getPrimitiveItemType(). The primitive types are the 19 primitive types of XML Schema, plus xs:integer, xs:dayTimeDuration and xs:yearMonthDuration, and xs:untypedAtomic. For external objects, the result is xs:anyAtomicType.- Returns:
- the primitive type
-
getUType
Determine the UType of the value. This delivers the same answer as getItemType().getUType()- Returns:
- the primitive UType
-
getCardinality
public final int getCardinality()Determine the static cardinality- Returns:
- code identifying the cardinality
- See Also:
-
copyAsSubType
Create a copy of this atomic value, with a different type label- Parameters:
typeLabel
- the type label of the new copy. The caller is responsible for checking that the value actually conforms to this type.- Returns:
- the copied value
-
isNaN
public boolean isNaN()Test whether the value is the special value NaN- Returns:
- true if the value is float NaN or double NaN or precisionDecimal NaN; otherwise false
-
getStringValue
Convert the value to a string, using the serialization rules. For atomic values this is the same as a cast; for sequence values it gives a space-separated list. This method is refined for AtomicValues so that it never throws an Exception.- Specified by:
getStringValue
in interfaceAtomicSequence
- Specified by:
getStringValue
in interfaceGroundedValue
- Specified by:
getStringValue
in interfaceItem
- Returns:
- the string value of the item
- See Also:
-
getPrimitiveStringValue
Convert the value to a string, using the serialization rules for the primitive type. This is the result of conversion to a string except that postprocessing defined by the saxon:preprocess facet is not (yet) applied.- Returns:
- the value converted to a string according to the rules for the primitive type
-
effectiveBooleanValue
Get the effective boolean value of the value- Specified by:
effectiveBooleanValue
in interfaceGroundedValue
- Returns:
- true, unless the value is boolean false, numeric zero, or zero-length string
- Throws:
XPathException
- if effective boolean value is not defined for this type (the default behaviour)
-
getComponent
Method to extract components of a value. Implemented by some subclasses, but defined at this level for convenience- Parameters:
component
- identifies the required component, as a constant defined in classAccessorFn
- Returns:
- the value of the requested component of this value
- Throws:
XPathException
- if a dynamic error occursUnsupportedOperationException
- if applied to a value of a type that has no components
-
checkPermittedContents
public void checkPermittedContents(SchemaType parentType, StaticContext env, boolean whole) throws XPathException Check statically that the results of the expression are capable of constructing the content of a given schema type.- Parameters:
parentType
- The schema typeenv
- the static contextwhole
- true if this atomic value accounts for the entire content of the containing node- Throws:
XPathException
- if the expression doesn't match the required content type
-
checkValidInJavascript
Check that the value can be handled in Saxon-JS- Throws:
XPathException
- if it can't be handled in Saxon-JS
-
asAtomic
Calling this method on a ConversionResult returns the AtomicValue that results from the conversion if the conversion was successful, and throws a ValidationException explaining the conversion error otherwise.Use this method if you are calling a conversion method that returns a ConversionResult, and if you want to throw an exception if the conversion fails.
- Specified by:
asAtomic
in interfaceConversionResult
- Returns:
- the atomic value that results from the conversion if the conversion was successful
-
toString
Get string value. In general toString() for an atomic value displays the value as it would be written in XPath: that is, as a literal if available, or as a call on a constructor function otherwise. -
iterate
Get an iterator over all the items in the sequence- Specified by:
iterate
in interfaceAtomicSequence
- Specified by:
iterate
in interfaceGroundedValue
- Specified by:
iterate
in interfaceItem
- Specified by:
iterate
in interfaceSequence
- Returns:
- an iterator over all the items
-
iterator
Returns a Java iterator over the atomic sequence.- Specified by:
iterator
in interfaceIterable<AtomicValue>
- Returns:
- an Iterator.
-
getGenre
Get the genre of this item- Specified by:
getGenre
in interfaceItem
- Returns:
- the genre: specifically,
Genre.ATOMIC
;
-