info.javelot.functionalj
Class ComposedFunction

java.lang.Object
  info.javelot.functionalj.Function
      info.javelot.functionalj.ReflectionFunction
          info.javelot.functionalj.MethodFunction
              info.javelot.functionalj.ComposedFunction

All Implemented Interfaces:

Serializable

public class ComposedFunction

extends MethodFunction

Combines two functions where the result of one function is used as a parameter to the other function.

Author:

Copyright © 2006 Frederic Daoud

See Also:

Serialized Form

Field Summary

Fields inherited from class info.javelot.functionalj.Function

m_class, m_name, m_object, m_parameters, m_targets

Constructor Summary

ComposedFunction(Function p_f, Function p_g)
Constructs a composed function with two functions, such that, given functions f and g, the resulting function is f o g, where 'o' is the composing operator as used in mathematics.

ComposedFunction(Function p_f, Function p_g, Function p_h)
Constructs a composed function with two functions, such that, given functions f, g and h, the resulting function is f o g o h, where 'o' is the composing operator as used in mathematics.

Method Summary

Function	addParameters(Object[] p_parameters) Returns a new ComposedFunction with the original f function, and a new g function on which the addParameters(Object[]) has been invoked.
Object	call() Invokes call() on the g function, supplies the result to the f function using objectOrParameter(Object), invokes call() on the resulting function, and returns the result.
boolean	isObjectPresent() Returns the value of g.isObjectPresent().
boolean	isObjectRequired() Returns the value of g.isObjectRequired().
protected Function	newInstance(Class p_class, Object[] p_parameters) Returns a new ComposedFunction object with the same f function and the value of g.newInstance(Class,Object[]), using g's target class.
Function	object(Object p_object) Returns a new ComposedFunction with the original f function, and a new g function on which the object(Object) has been invoked.
String	toString() Returns a String representation of the Function objects of which this function is composed.

Methods inherited from class info.javelot.functionalj.MethodFunction

getAllTargets, getInsertIndex, getParameterTypes, invoke

Methods inherited from class info.javelot.functionalj.Function

addParameter, addParameters, addParameters, addParameters, addParameters, getName, getObject, getParameters, getTargetClass, getTargets, objectOrParameter

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

ComposedFunction

public ComposedFunction(Function p_f,
                        Function p_g)
                 throws FunctionException

Constructs a composed function with two functions, such that, given functions f and g, the resulting function is f o g, where 'o' is the composing operator as used in mathematics. Therefore, calling the resulting function is equivalent to calling f.objectOrParameter(g.call()).call().

Throws:

FunctionException - thrown if either of the two functions supplied is null.

ComposedFunction

public ComposedFunction(Function p_f,
                        Function p_g,
                        Function p_h)
                 throws FunctionException

Constructs a composed function with two functions, such that, given functions f, g and h, the resulting function is f o g o h, where 'o' is the composing operator as used in mathematics. Therefore, calling the resulting function is equivalent to calling f.objectOrParameter(g.objectOrParameter(h.call()).call()).call().

Throws:

FunctionException - thrown if either of the three functions supplied is null.

Method Detail

isObjectRequired

public boolean isObjectRequired()

Returns the value of g.isObjectRequired().

Specified by:

isObjectRequired in class Function

Returns:

the value returned by isObjectRequired() of the g function.

isObjectPresent

public boolean isObjectPresent()

Returns the value of g.isObjectPresent().

Overrides:

isObjectPresent in class Function

Returns:

the value returned by isObjectPresent() of the g function.

newInstance

protected Function newInstance(Class p_class,
                               Object[] p_parameters)

Returns a new ComposedFunction object with the same f function and the value of g.newInstance(Class,Object[]), using g's target class.

Specified by:

newInstance in class Function

Parameters:

p_class - the class of the target.

p_parameters - the parameters that have been supplied.

Returns:

a new ComposedFunction object with the same f function and the value returned by newInstance(Class,Object[]) of the g function using g's target class.

addParameters

public Function addParameters(Object[] p_parameters)
                       throws FunctionException

Returns a new ComposedFunction with the original f function, and a new g function on which the addParameters(Object[]) has been invoked.

Overrides:

addParameters in class Function

Parameters:

p_parameters - the parameters to be added to the list of parameters that are supplied to the function.

Returns:

a new Function object with the parameters added to the list of supplied parameters.

Throws:

FunctionException - thrown if the additional parameters cause the list of supplied parameters not to match any of the possible targets.

object

public Function object(Object p_object)
                throws FunctionException

Returns a new ComposedFunction with the original f function, and a new g function on which the object(Object) has been invoked.

Specified by:

object in class Function

Throws:

FunctionException

call

public Object call()
            throws FunctionException

Invokes call() on the g function, supplies the result to the f function using objectOrParameter(Object), invokes call() on the resulting function, and returns the result.

Overrides:

call in class ReflectionFunction

Returns:

the result of f.objectOrParameter(g.call()).call().

Throws:

FunctionException - thrown if an exception occurs when invoking the target, if an object on which to invoke the target is required but none has been supplied, or if all of the potential targets expect more parameters than have been supplied.

toString

public String toString()

Returns a String representation of the Function objects of which this function is composed.

Overrides:

toString in class Function

Returns:

a String representation of the Function objects of which this function is composed, by calling Function.toString() on each function.

See Also:

Function.toString().