Package com.singularsys.extensions.lambda

Class LambdaFunction

java.lang.Object

com.singularsys.jep.functions.PostfixMathCommand

com.singularsys.jep.misc.MacroFunction

com.singularsys.extensions.lambda.LambdaFunction

All Implemented Interfaces:

JepComponent, PostfixMathCommandI, Serializable

public class LambdaFunction
extends MacroFunction

PostfixMathCommand representing a lambda functions. These are typically created by the LambdaFunGenerator.

Since:

Extensions 2.1

See Also:

• Serialized Form

Field Summary

Fields

Modifier and Type	Field	Description
static boolean	DEBUG

Fields inherited from class com.singularsys.jep.misc.MacroFunction

ev, expression, jep, nf, preCompiled, sv, topNode, varNames, vars

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

curNumberOfParameters, description, name, NaN, numberOfParameters

Constructor Summary

Constructors

Constructor	Description
LambdaFunction(String funName, String[] parameters, String expression, Node root, Signature sig)	Create a lambda function from a node tree.

Method Summary

Modifier and Type	Method	Description
boolean	checkNumberOfParameters(int n)	Checks the number of parameters of the function.
String	getDescription()	Return a description of the function from the properties file.
JepComponent	getLightWeightInstance()	Returns a new copy of the function, uses the MacroFunction(String, String[], String, Node) constructor.
int	getNumberOfParameters()	Return the required number of parameters.
Signature	getSignature()	Get the signature of the function
void	init(Jep j)	Initialise the LambdaFunction.
void	run(Stack<Object> stack)	Calculates the value of the expression.
void	setCurNumberOfParameters(int n)	Sets the number of current number of parameters used in the next call of run().
void	setName(String newName)	Rename the function.
String	toString()	Prints the function in the form [x,y]=>x^2+y^2

Methods inherited from class com.singularsys.jep.misc.MacroFunction

getParameterNames, getTopNode, getVars

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

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

Methods inherited from class java.lang.Object

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

Field Details

DEBUG

public static boolean DEBUG

Constructor Details

LambdaFunction

public LambdaFunction(String funName,
 String[] parameters,
 String expression,
 Node root,
 Signature sig)

Create a lambda function from a node tree. The init(Jep) method must be called to compile the expression.

Parameters:

funName - function name

parameters - list of parameters

expression - string representation of equation

root - root of expressions tree.

sig -

See Also:

• LambdaFunGenerator

Method Details

getNumberOfParameters

public int getNumberOfParameters()

Description copied from class: PostfixMathCommand

Return the required number of parameters.

Specified by:

getNumberOfParameters in interface PostfixMathCommandI

Overrides:

getNumberOfParameters in class PostfixMathCommand

Returns:

allowable number of parameters, -1 if a variable number is allowed

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> stack)
         throws EvaluationException

Description copied from class: MacroFunction

Calculates the value of the expression.

Specified by:

run in interface PostfixMathCommandI

Overrides:

run in class MacroFunction

Parameters:

stack - arguments for function

Throws:

EvaluationException - if the calculation cannot be performed

init

public void init(Jep j)

Initialise the LambdaFunction. As well as performing the actions in MacroFunction.init(Jep) it searches for any nested lambda functions and complies those.

Specified by:

init in interface JepComponent

Overrides:

init in class MacroFunction

Parameters:

j - Jep instance

setName

public void setName(String newName)

Rename the function. Also changes the names of variables for this lambda function and any nested lambda functions.

Specified by:

setName in interface PostfixMathCommandI

Overrides:

setName in class MacroFunction

Parameters:

newName - new name for the function

toString

public String toString()

Prints the function in the form [x,y]=>x^2+y^2

Overrides:

toString in class MacroFunction

getLightWeightInstance

public JepComponent getLightWeightInstance()

Description copied from class: MacroFunction

Returns a new copy of the function, uses the MacroFunction(String, String[], String, Node) constructor.

Specified by:

getLightWeightInstance in interface JepComponent

Overrides:

getLightWeightInstance in class MacroFunction

Returns:

either a new instance, null or 'this'.

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 MacroFunction

Returns:

the description of the function

getSignature

public Signature getSignature()

Get the signature of the function

Returns:

the signature