| java.lang.Object net.sf.saxon.value.Value net.sf.saxon.value.AtomicValue
All known Subclasses: net.sf.saxon.value.DurationValue, net.sf.saxon.value.ObjectValue, net.sf.saxon.value.StringValue, net.sf.saxon.value.BooleanValue, net.sf.saxon.value.Base64BinaryValue, net.sf.saxon.value.QNameValue, net.sf.saxon.value.HexBinaryValue, net.sf.saxon.value.NumericValue, net.sf.saxon.value.CalendarValue,
AtomicValue | abstract public class AtomicValue extends Value implements Item(Code) | | The AtomicValue class corresponds to the concept of an atomic value in the
XPath 2.0 data model. Atomic values belong to one of the 19 primitive types
defined in XML Schema; or they are of type xdt:untypedAtomic; or they are
"external objects", representing a Saxon extension to the XPath 2.0 type system.
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 |
Method Summary | |
public 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. | final public AtomicValue | convert(int requiredType, XPathContext context) Convert the value to a given type. | public AtomicValue | convert(AtomicType targetType, XPathContext context, boolean validate) Convert the value to a given type. | abstract public AtomicValue | convertPrimitive(BuiltInAtomicType requiredType, boolean validate, XPathContext context) Convert a value to another primitive data type, with control over how validation is
handled.
Parameters: requiredType - type code of the required atomic type Parameters: validate - true if validation is required. | final public void | display(int level, NamePool pool, PrintStream out) | public boolean | effectiveBooleanValue(XPathContext context) | final public String | evaluateAsString(XPathContext context) | public Item | evaluateItem(XPathContext context) | final public int | getCardinality() | public AtomicValue | getComponent(int component) Method to extract components of a value. | public int | getImplementationMethod() An implementation of Expression must provide at least one of the methods evaluateItem(), iterate(), or process(). | final public int | getLength() | public AtomicValue | getPrimitiveValue() Get the primitive value (the value in the value space). | abstract public String | 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. | public CharSequence | getStringValueCS() Get the value of the item as a CharSequence. | final public SequenceIterator | getTypedValue() | public boolean | hasBuiltInType() Test whether the type of this atomic value is a built-in type. | final public SequenceIterator | iterate(XPathContext context) | public void | process(XPathContext context) | public boolean | schemaEquals(Value obj) Compare two values for equality. | public String | toString() Get string value. |
checkPermittedContents | public void checkPermittedContents(SchemaType parentType, StaticContext env, boolean whole) throws XPathException(Code) | | Check statically that the results of the expression are capable of constructing the content
of a given schema type.
Parameters: parentType - The schema type Parameters: env - the static context Parameters: whole - true if this atomic value accounts for the entire content of the containing node throws: net.sf.saxon.trans.XPathException - if the expression doesn't match the required content type |
convert | final public AtomicValue convert(int requiredType, XPathContext context) throws XPathException(Code) | | Convert the value to a given type. The result of the conversion will be an
atomic value of the required type. This method works only where the target
type is a built-in type.
Parameters: requiredType - type code of the required atomic type Parameters: context - the result of the conversion, if conversion was possible. Thiswill always be an instance of the class corresponding to the typeof value requested throws: XPathException - if conversion is not allowed for thisrequired type, or if the particular value cannot be converted |
convert | public AtomicValue convert(AtomicType targetType, XPathContext context, boolean validate)(Code) | | Convert the value to a given type. The result of the conversion will be
an atomic value of the required type. This method works where the target
type is a built-in atomic type and also where it is a user-defined atomic
type.
Parameters: targetType - the type to which the value is to be converted Parameters: context - provides access to conversion context Parameters: validate - true if validation is required, false if the caller already knows that thevalue is valid the value after conversion if successful; or a ValidationErrorValue if conversion failed. Thecaller must check for this condition. Validation may fail even if validation was not requested. |
convertPrimitive | abstract public AtomicValue convertPrimitive(BuiltInAtomicType requiredType, boolean validate, XPathContext context)(Code) | | Convert a value to another primitive data type, with control over how validation is
handled.
Parameters: requiredType - type code of the required atomic type Parameters: validate - true if validation is required. If set to false, the caller guarantees thatthe value is valid for the target data type, and that further validation is therefore not required.Note that a validation failure may be reported even if validation was not requested. Parameters: context - The conversion context to be used. This is required at present only when converting toa date or time: it provides the implicit timezone. the result of the conversion, if successful. If unsuccessful, the value returnedwill be an ErrorValue. The caller must check for this condition. No exception is thrown, insteadthe exception will be encapsulated within the ErrorValue. |
display | final public void display(int level, NamePool pool, PrintStream out)(Code) | | Diagnostic print of expression structure
Parameters: level - the indentation level of the output Parameters: out - |
effectiveBooleanValue | public boolean effectiveBooleanValue(XPathContext context) throws XPathException(Code) | | Get the effective boolean value of the value
Parameters: context - the evaluation context (not used in this implementation) true, unless the value is boolean false, numeric zero, orzero-length string |
evaluateItem | public Item evaluateItem(XPathContext context) throws XPathException(Code) | | Evaluate the value (this simply returns the value unchanged)
Parameters: context - the evaluation context (not used in this implementation) the value, unchanged throws: XPathException - |
getComponent | public AtomicValue getComponent(int component) throws XPathException(Code) | | Method to extract components of a value. Implemented by some subclasses,
but defined at this level for convenience
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getImplementationMethod | public int getImplementationMethod()(Code) | | An implementation of Expression must provide at least one of the methods evaluateItem(), iterate(), or process().
This method indicates which of these methods is prefered.
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getLength | final public int getLength()(Code) | | Get the length of the sequence
always 1 for an atomic value |
getPrimitiveValue | public AtomicValue getPrimitiveValue()(Code) | | Get the primitive value (the value in the value space). This returns an
AtomicValue of a class that would be used to represent the primitive value.
In effect this means that for built-in types, it returns the value itself,
but for user-defined type, it returns the primitive value minus the type
annotation. Note that getItemType() when applied to the result of this
function does not not necessarily return a primitive type: for example, this
function may return a value of type xdt:dayTimeDuration, which is not a
primitive type as defined by
net.sf.saxon.type.Type.isPrimitiveType(int) |
getStringValue | abstract public String getStringValue()(Code) | | 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.
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getStringValueCS | public CharSequence getStringValueCS()(Code) | | 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.
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getTypedValue | final public SequenceIterator getTypedValue()(Code) | | Get the typed value of this item
the typed value of the expression (which is this value) |
hasBuiltInType | public boolean hasBuiltInType()(Code) | | Test whether the type of this atomic value is a built-in type.
Default implementation returns true.
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iterate | final public SequenceIterator iterate(XPathContext context)(Code) | | Iterate over the (single) item in the sequence
Parameters: context - the evaluation context (not used in this implementation) a SequenceIterator that iterates over the single item in thisvalue |
process | public void process(XPathContext context) throws XPathException(Code) | | Process the instruction, without returning any tail calls
Parameters: context - The dynamic context, giving access to the current node,the current variables, etc. |
schemaEquals | public boolean schemaEquals(Value obj)(Code) | | Compare two values for equality. This supports identity constraints in XML Schema,
which allow list-valued elements and attributes to participate in key and uniqueness constraints.
This method returns false if any error occurs during the comparison, or if any of the items
in either sequence is a node rather than an atomic value. The default implementation of
schemaEquals() is the same as equals(), but subclasses can override this.
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toString | public String toString()(Code) | | 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.
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Fields inherited from net.sf.saxon.value.Value | final public static Class[] EMPTY_CLASS_ARRAY(Code)(Java Doc)
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Methods inherited from net.sf.saxon.value.Value | public static Item asItem(ValueRepresentation value, XPathContext context) throws XPathException(Code)(Java Doc) public static SequenceIterator asIterator(ValueRepresentation val, XPathContext context) throws XPathException(Code)(Java Doc) public static Value asValue(ValueRepresentation val)(Code)(Java Doc) public void checkPermittedContents(SchemaType parentType, StaticContext env, boolean whole) throws XPathException(Code)(Java Doc) public static CharSequence collapseWhitespace(CharSequence in)(Code)(Java Doc) public static Object convert(Item item) throws XPathException(Code)(Java Doc) public static Value convertJavaObjectToXPath(Object object, SequenceType requiredType, Configuration config) throws XPathException(Code)(Java Doc) public Object convertToJava(Class target, XPathContext context) throws XPathException(Code)(Java Doc) public void display(int level, NamePool pool, PrintStream out)(Code)(Java Doc) public boolean effectiveBooleanValue(XPathContext context) throws XPathException(Code)(Java Doc) public boolean equals(Object obj)(Code)(Java Doc) public String evaluateAsString(XPathContext context) throws XPathException(Code)(Java Doc) public Item evaluateItem(XPathContext context) throws XPathException(Code)(Java Doc) public int getCardinality()(Code)(Java Doc) final public int getDependencies()(Code)(Java Doc) public ItemType getItemType(TypeHierarchy th)(Code)(Java Doc) public static SequenceIterator getIterator(ValueRepresentation val) throws XPathException(Code)(Java Doc) public int getLength() throws XPathException(Code)(Java Doc) final public Container getParentExpression()(Code)(Java Doc) public int getSpecialProperties()(Code)(Java Doc) public String getStringValue() throws XPathException(Code)(Java Doc) public int hashCode()(Code)(Java Doc) public Item itemAt(int n) throws XPathException(Code)(Java Doc) final public Iterator iterateSubExpressions()(Code)(Java Doc) public static QNameValue makeQNameValue(Object object, Configuration config)(Code)(Java Doc) public static CharSequence normalizeWhitespace(CharSequence in)(Code)(Java Doc) final public Expression optimize(Optimizer opt, StaticContext env, ItemType contextItemType)(Code)(Java Doc) public void process(XPathContext context) throws XPathException(Code)(Java Doc) final public Expression promote(PromotionOffer offer)(Code)(Java Doc) public Value reduce() throws XPathException(Code)(Java Doc) public boolean schemaEquals(Value obj)(Code)(Java Doc) final public Expression simplify(StaticContext env)(Code)(Java Doc) public static double stringToNumber(CharSequence s) throws NumberFormatException(Code)(Java Doc) public String toString()(Code)(Java Doc) public static CharSequence trimWhitespace(CharSequence in)(Code)(Java Doc) final public Expression typeCheck(StaticContext env, ItemType contextItemType)(Code)(Java Doc)
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