Package net.sf.saxon.value

Class AtomicValue

    • Constructor Detail

      • AtomicValue

        public AtomicValue()

    • Method Detail

      • setTypeLabel

        public void setTypeLabel​(AtomicType type)
        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, use copyAsSubType(net.sf.saxon.type.AtomicType)
        Parameters:
        type - the type label to be set

      • getSchemaComparable

        public abstract java.lang.Comparable 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 interface AtomicSequence
        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 strings
        implicitTimezone - 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

        public AtomicMatchKey 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

        public abstract boolean equals​(java.lang.Object o)
        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().

        Overrides:
        equals in class java.lang.Object
        Parameters:
        o - the other value
        Returns:
        true if the other operand is an atomic value and the two values are equal as defined by the XPath eq operator

      • isIdentical

        public boolean isIdentical​(AtomicValue v)
        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

        public boolean isIdentical​(IdentityComparable other)
        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 interface IdentityComparable
        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 interface IdentityComparable
        Returns:
        a hashCode suitable for use when testing for identity.

      • getCanonicalLexicalRepresentation

        public java.lang.CharSequence 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 interface AtomicSequence
        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

        public final AtomicValue 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 AtomicSequence
        Specified by:
        itemAt in interface GroundedValue
        Specified by:
        itemAt in interface Item
        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

        public final AtomicType getItemType()
        Determine the data type of the value
        Returns:
        the type annotation of the atomic value

      • getPrimitiveType

        public abstract BuiltInAtomicType 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

        public final UType 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:
        Cardinality

      • copyAsSubType

        public abstract AtomicValue copyAsSubType​(AtomicType typeLabel)
        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

        public final java.lang.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. This method is refined for AtomicValues so that it never throws an Exception.
        Specified by:
        getStringValue in interface AtomicSequence
        Specified by:
        getStringValue in interface GroundedValue
        Specified by:
        getStringValue in interface Item
        Returns:
        the string value of the item
        See Also:
        Item.getStringValueCS()

      • getPrimitiveStringValue

        protected abstract java.lang.CharSequence 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

        public boolean effectiveBooleanValue()
                              throws XPathException
        Get the effective boolean value of the value
        Specified by:
        effectiveBooleanValue in interface GroundedValue
        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

        public AtomicValue getComponent​(AccessorFn.Component component)
                         throws XPathException
        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 class AccessorFn
        Returns:
        the value of the requested component of this value
        Throws:
        XPathException - if a dynamic error occurs
        java.lang.UnsupportedOperationException - 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 type
        env - the static context
        whole - 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

        public void checkValidInJavascript()
                            throws XPathException
        Check that the value can be handled in Saxon-JS
        Throws:
        XPathException - if it can't be handled in Saxon-JS

      • asAtomic

        public AtomicValue 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 interface ConversionResult
        Returns:
        the atomic value that results from the conversion if the conversion was successful

      • toString

        public java.lang.String 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.
        Overrides:
        toString in class java.lang.Object

      • iterator

        public java.util.Iterator<AtomicValue> iterator()
        Returns a Java iterator over the atomic sequence.
        Specified by:
        iterator in interface java.lang.Iterable<AtomicValue>
        Returns:
        an Iterator.

      • getGenre

        public final Genre getGenre()
        Get the genre of this item
        Specified by:
        getGenre in interface Item
        Returns:
        the genre: specifically, Genre.ATOMIC;