Package com.singularsys.jep.functions

Class UnaryFunction

java.lang.Object

com.singularsys.jep.functions.PostfixMathCommand

com.singularsys.jep.functions.UnaryFunction

All Implemented Interfaces:

PostfixMathCommandI, Serializable

Direct Known Subclasses:

Abs, ArcCosine, ArcCosineH, ArcSine, ArcSineH, ArcTangent, ArcTanH, Arg, BitComp, Ceil, Conjugate, Cosecant, Cosine, CosineH, Cotangent, Exp, Factorial, Floor, Identity, Imaginary, IsInfinite, IsNaN, IsNull, JepTest.MyUnary, Length, Logarithm, LogBase2, LowerCase, NaturalLogarithm, Not, NullWrappedUnary, Real, Secant, Signum, Sine, SineH, SquareRoot, Str, StrictNaturalLogarithm, Tangent, TanH, Trim, UMinus, UpperCase

public abstract class UnaryFunction
extends PostfixMathCommand

Convenient base class for unary functions. Defines an Object eval(Object arg) method for calculating the result.

Author:

Richard Morris

See Also:

• Serialized Form

Field Summary

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

curNumberOfParameters, name, NaN, numberOfParameters

Constructor Summary

Constructors

Constructor	Description
UnaryFunction()	Default constructor.

Method Summary

Modifier and Type	Method	Description
abstract Object	eval(Object arg)	Evaluate the function
static <T> UnaryFunction	instanceOf(Class<T> type, Function<T,? super Object> fun)	Create a UnaryFunction from a lambda expression where the argument is of a specified type.
static UnaryFunction	instanceOf(Function<Object,? super Object> fun)	Create a UnaryFunction from a lambda expression where the argument can be any Object.
void	run(Stack<Object> stack)	Used for compatibility with StandardEvaluator Simple calls eval(Object) placing result on stack.

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

asArray, asBool, asDouble, asInt, asLong, asStrictInt, asString, checkNumberOfParameters, getName, getNumberOfParameters, setCurNumberOfParameters, setName, toString, toString

Methods inherited from class java.lang.Object

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

Constructor Details

UnaryFunction

public UnaryFunction()

Default constructor. Sets the function to have a single argument.

Method Details

run

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

Used for compatibility with StandardEvaluator Simple calls eval(Object) placing result on stack.

Specified by:

run in interface PostfixMathCommandI

Overrides:

run in class PostfixMathCommand

Parameters:

stack - arguments for function

Throws:

EvaluationException - if function cannot be evaluated

eval

public abstract Object eval(Object arg)
                     throws EvaluationException

Evaluate the function

Parameters:

arg - the single argument passed in

Returns:

the result of the function

Throws:

EvaluationException

instanceOf

public static UnaryFunction instanceOf(Function<Object,? super Object> fun)

Create a UnaryFunction from a lambda expression where the argument can be any Object. For example UnaryFunction.instanceOf(x -> 1.0 / ((Number) x).doubleValue())

Parameters:

fun - the lambda function

Returns:

a new UnaryFunction instance

Since:

Jep 4.0

instanceOf

public static <T> UnaryFunction instanceOf(Class<T> type,
 Function<T,? super Object> fun)

Create a UnaryFunction from a lambda expression where the argument is of a specified type. For example UnaryFunction.instanceOf(Integer.class, x -> -x ) or using a method reference UnaryFunction.instanceOf(Double.class,Math::cbrt). The eval(Object) method will throw an IllegalParameterException if the argument is not of the correct type.

Type Parameters:

T - type of arguments and return value

Parameters:

type - type of the arguments

fun - the lambda function

Returns:

a new UnaryFunction instance

Since:

Jep 4.0