Package com.singularsys.extensions.chained

Class ChainedNaryFunction

java.lang.Object

com.singularsys.jep.functions.PostfixMathCommand

com.singularsys.extensions.chained.ChainedNaryFunction

All Implemented Interfaces:

ChainedFunctionI, DirtyFunction, JepComponent, PostfixMathCommandI, Serializable

public class ChainedNaryFunction
extends PostfixMathCommand
implements ChainedFunctionI, JepComponent, DirtyFunction

Converts a NaryFunction so it can be used in a chain. A nary function that takes n arguments is converted to an nary function with n-1 arguments. A unary function with two arguments f(x,y) will be converted to a unary function F(x) can be used in the middle of a chain as

[1..10] . F(5) . fold([x,y]=>x+y) 

The apply(Evaluator, Node, Object) method will first evaluate the child of the node then call the nary function f(x,y) with the first argument from the child and the second argument from the chain.

See Also:

• Serialized Form

Field Summary

Fields inherited from class com.singularsys.jep.functions.PostfixMathCommand

curNumberOfParameters, description, name, NaN, numberOfParameters

Constructor Summary

Constructors

Constructor	Description
ChainedNaryFunction(NaryFunction inner)

Method Summary

Modifier and Type	Method	Description
Object	apply(Evaluator ev, Node node, Object lhs)	Evaluate a chained function using an additional argument.
boolean	checkNumberOfParameters(int n)	Checks the number of parameters of the function.
String	getDescription()	Return a description of the function from the properties file.
PostfixMathCommandI	getInner()
JepComponent	getLightWeightInstance()	Gets a light-weight instance suitable for using in multiple threads.
void	init(Jep jep)	Initialize the component.
void	run(Stack<Object> s)	Throws an exception because this method should never be called under normal circumstances.
void	setCurNumberOfParameters(int n)	Sets the number of current number of parameters used in the next call of run().

Methods inherited from class com.singularsys.jep.functions.PostfixMathCommand

asArray, asBool, asDouble, asInt, asLong, asStrictInt, asString, asType, getDescription, getDescriptionWithType, getName, getNumberOfParameters, setDescription, setName, toString, toString

Methods inherited from class java.lang.Object

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

Constructor Details

ChainedNaryFunction

public ChainedNaryFunction(NaryFunction inner)

Method Details

checkNumberOfParameters

public boolean checkNumberOfParameters(int n)

Description copied from class: PostfixMathCommand

Checks the number of parameters of the function. Functions which set numberOfParameter=-1 should overload this method

Specified by:

checkNumberOfParameters in interface PostfixMathCommandI

Overrides:

checkNumberOfParameters in class PostfixMathCommand

Parameters:

n - number of parameters function will be called with.

Returns:

false if an illegal number of parameters is supplied, true otherwise.

setCurNumberOfParameters

public void setCurNumberOfParameters(int n)

Description copied from class: PostfixMathCommand

Sets the number of current number of parameters used in the next call of run(). This method is only called when the reqNumberOfParameters is -1.

Specified by:

setCurNumberOfParameters in interface PostfixMathCommandI

Overrides:

setCurNumberOfParameters in class PostfixMathCommand

Parameters:

n - number of parameter for next call of function

run

public void run(Stack<Object> s)
         throws EvaluationException

Description copied from class: PostfixMathCommand

Throws an exception because this method should never be called under normal circumstances. Each function should use its own run() method for evaluating the function. This includes popping off the parameters from the stack, and pushing the result back on the stack.

Specified by:

run in interface PostfixMathCommandI

Overrides:

run in class PostfixMathCommand

Parameters:

s - arguments for function

Throws:

EvaluationException - if function cannot be evaluated

apply

public Object apply(Evaluator ev,
 Node node,
 Object lhs)
             throws EvaluationException

Description copied from interface: ChainedFunctionI

Evaluate a chained function using an additional argument.

Specified by:

apply in interface ChainedFunctionI

Parameters:

ev - the evaluator

node - top node of function

lhs - additional argument from previous element in the chain

Returns:

Throws:

EvaluationException

init

public void init(Jep jep)

Description copied from interface: JepComponent

Initialize the component. This method is called whenever a component is added to Jep. Hence, it allows components to keep track of the other components they may rely on.

Specified by:

init in interface JepComponent

Parameters:

jep - the current Jep instance

getLightWeightInstance

public JepComponent getLightWeightInstance()

Description copied from interface: JepComponent

Gets a light-weight instance suitable for using in multiple threads.

Specified by:

getLightWeightInstance in interface JepComponent

Returns:

either a new instance, null or 'this'.

getInner

public PostfixMathCommandI getInner()

getDescription

public String getDescription()

Description copied from class: PostfixMathCommand

Return a description of the function from the properties file. The property name is the class name followed by ".description". The property is found using the JepMessages class, which can be configured to add additional properties files. If PostfixMathCommand.setDescription(String) has been called, return the description set by that method instead.

Specified by:

getDescription in interface PostfixMathCommandI

Overrides:

getDescription in class PostfixMathCommand

Returns:

the description of the function