Package net.sf.saxon.value

Class NumericValue

    • Constructor Detail

      • NumericValue

        public NumericValue()

    • Method Detail

      • parseNumber

        public static NumericValue parseNumber​(java.lang.String in)
        Get a numeric value by parsing a string; the type of numeric value depends on the lexical form of the string, following the rules for XPath numeric literals.
        Parameters:
        in - the input string
        Returns:
        a NumericValue representing the value of the string. Returns Double.NaN if the value cannot be parsed as a string.

      • getDoubleValue

        public abstract double getDoubleValue()
        Get the numeric value as a double
        Returns:
        A double representing this numeric value; NaN if it cannot be converted

      • getFloatValue

        public abstract float getFloatValue()
        Get the numeric value converted to a float
        Returns:
        a float representing this numeric value; NaN if it cannot be converted

      • getDecimalValue

        public abstract java.math.BigDecimal getDecimalValue()
                                              throws ValidationException
        Get the numeric value converted to a decimal
        Returns:
        a decimal representing this numeric value;
        Throws:
        ValidationException - if the value cannot be converted, for example if it is NaN or infinite

      • effectiveBooleanValue

        public abstract boolean effectiveBooleanValue()
        Get the effective boolean value of the value. This override of this method throws no exceptions.
        Specified by:
        effectiveBooleanValue in interface GroundedValue
        Overrides:
        effectiveBooleanValue in class AtomicValue
        Returns:
        true, unless the value is boolean false, numeric zero, or zero-length string

      • isInteger

        public static boolean isInteger​(AtomicValue value)
        Test whether a value is an integer (an instance of a subtype of xs:integer)
        Parameters:
        value - the value being tested
        Returns:
        true if the value is an instance of xs:integer or a type derived therefrom

      • longValue

        public abstract long longValue()
                        throws XPathException
        Return the numeric value as a Java long.
        Returns:
        the numeric value as a Java long. This performs truncation towards zero.
        Throws:
        XPathException - if the value cannot be converted

      • negate

        public abstract NumericValue negate()
        Change the sign of the number
        Returns:
        a value, of the same type as the original, with its sign inverted

      • floor

        public abstract NumericValue floor()
        Implement the XPath floor() function
        Returns:
        a value, of the same type as that supplied, rounded towards minus infinity

      • ceiling

        public abstract NumericValue ceiling()
        Implement the XPath ceiling() function
        Returns:
        a value, of the same type as that supplied, rounded towards plus infinity

      • round

        public abstract NumericValue round​(int scale)
        Implement the XPath round() function
        Parameters:
        scale - the number of decimal places required in the result (supply 0 for rounding to an integer)
        Returns:
        a value, of the same type as that supplied, rounded towards the nearest whole number (0.5 rounded up)

      • roundHalfToEven

        public abstract NumericValue roundHalfToEven​(int scale)
        Implement the XPath 2.0 round-half-to-even() function
        Parameters:
        scale - the decimal position for rounding: e.g. 2 rounds to a multiple of 0.01, while -2 rounds to a multiple of 100
        Returns:
        a value, of the same type as the original, rounded towards the nearest multiple of 10**(-scale), with rounding towards the nearest even number if two values are equally near

      • signum

        public abstract int signum()
        Ask whether the value is negative, zero, or positive
        Returns:
        -1 if negative, 0 if zero (including negative zero) or NaN, +1 if positive

      • isNegativeZero

        public boolean isNegativeZero()
        Ask whether this value is negative zero
        Returns:
        true if this value is float or double negative zero

      • isWholeNumber

        public abstract boolean isWholeNumber()
        Ask whether the value is a whole number, that is, whether it compares equal to some integer
        Returns:
        true if the value is a whole number

      • asSubscript

        public abstract int asSubscript()
        Test whether a number is a possible subscript into a sequence, that is, a whole number greater than zero and less than 2^31
        Returns:
        the number as an int if it is a possible subscript, or -1 otherwise

      • abs

        public abstract NumericValue abs()
        Get the absolute value as defined by the XPath abs() function
        Returns:
        the absolute value
        Since:
        9.2

      • getXPathMatchKey

        public final AtomicMatchKey getXPathMatchKey​(StringCollator collator,
                                             int implicitTimezone)
        Get a Comparable value that implements the XPath ordering comparison semantics for this value. Returns null if the value is not comparable according to XPath rules. The implementation for all kinds of NumericValue returns the value itself.
        Specified by:
        getXPathMatchKey in class AtomicValue
        Parameters:
        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:
        a collation key that implements the comparison semantics

      • getXPathComparable

        public XPathComparable getXPathComparable​(StringCollator collator,
                                          int implicitTimezone)
                                   throws NoDynamicContextException
        Description copied from class: AtomicValue
        Get an object value that implements the XPath equality and ordering comparison semantics for this value. A collation is supplied for comparing strings, and an implicit timezone for comparing date/time values that have no saved timezone. An atomic value may return itself as the result, provided that its ordering rules are independent of the collation and timezone, and provided that it implements the XPathComparable interface: which means that its compareTo, equals, and hashCode methods must be compatible with the rules for XPath value comparisons.
        Specified by:
        getXPathComparable in class AtomicValue
        Parameters:
        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 that implements the XPath value comparison semantics with respect to this atomic value. For an atomic type that is not ordered (according to XPath rules), return null.
        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.

      • getXPathComparable

        public XPathComparable getXPathComparable()
        Description copied from interface: ContextFreeAtomicValue
        Get an XPathComparable object that supports the semantics of context-free eq and lt comparisons between atomic values. Note that in many cases the returned XPathComparable will be the AtomicValue itself; however because of the constraints of the generic Comparable interface, this cannot be assumed.
        Specified by:
        getXPathComparable in interface ContextFreeAtomicValue
        Returns:
        an XPathComparable that can be used in comparisons with other atomic values.

      • compareTo

        public int compareTo​(XPathComparable other)
        Compare the value to another numeric value
        Specified by:
        compareTo in interface java.lang.Comparable<XPathComparable>
        Parameters:
        other - The other numeric value
        Returns:
        -1 if this one is the lower, 0 if they are numerically equal, +1 if this one is the higher, or if either value is NaN. Where NaN values are involved, they should be handled by the caller before invoking this method.
        Throws:
        java.lang.ClassCastException - if the other value is not a NumericValue (the parameter is declared as Object to satisfy the Comparable interface)

      • compareTo

        public abstract int compareTo​(long other)
        Compare the value to a long
        Parameters:
        other - the value to be compared with
        Returns:
        -1 if this is less, 0 if this is equal, +1 if this is greater or if this is NaN

      • equals

        public final boolean equals​(java.lang.Object other)
        The equals() function compares numeric equality among integers, decimals, floats, doubles, and their subtypes.
        Overrides:
        equals in class AtomicValue
        Parameters:
        other - the value to be compared with this one
        Returns:
        true if the two values are numerically equal

      • hashCode

        public abstract int hashCode()
        hashCode() must be the same for two values that are equal. One way to ensure this is to convert the value to a double, and take the hashCode of the double. But this is expensive in the common case where we are comparing integers. So we adopt the rule: for values that are in the range of a Java Integer, we use the int value as the hashcode. For values outside that range, we convert to a double and take the hashCode of the double. This method needs to have a compatible implementation in each subclass.
        Overrides:
        hashCode in class AtomicValue
        Returns:
        the hash code of the numeric value

      • show

        public java.lang.String show()
        Produce a string representation of the value
        Overrides:
        show in class AtomicValue
        Returns:
        The result of casting the number to a string