org.jaxen.function

Class SumFunction

public class SumFunction extends Object implements Function

4.4 number sum(node-set)

The sum function returns the sum, for each node in the argument node-set, of the result of converting the string-values of the node to a number.

Author: bob mcwhirter (bob @ werken.com)

See Also: Section 4.4 of the XPath Specification

Constructor Summary
SumFunction()
Create a new SumFunction object.
Method Summary
Objectcall(Context context, List args)
Returns the sum of its arguments.
static Doubleevaluate(Object obj, Navigator nav)
Returns the sum of the items in a list.

Constructor Detail

SumFunction

public SumFunction()
Create a new SumFunction object.

Method Detail

call

public Object call(Context context, List args)
Returns the sum of its arguments.

Parameters: context the context at the point in the expression when the function is called args a list that contains exactly one item, also a List

Returns: a Double containing the sum of the items in args.get(0)

Throws: FunctionCallException if args has more or less than one item; or if the first argument is not a List

evaluate

public static Double evaluate(Object obj, Navigator nav)
Returns the sum of the items in a list. If necessary, each item in the list is first converted to a Double as if by the XPath number() function.

Parameters: obj a List of numbers to be summed nav ignored

Returns: the sum of the list

Throws: FunctionCallException if obj is not a List