edu.neu.ccs.parser
Class AbstractFunction

java.lang.Object
  edu.neu.ccs.parser.AbstractFunction

Direct Known Subclasses:

SimpleFunction

public abstract class AbstractFunction

extends Object

Class AbstractFunction encapsulates a function definition and its corresponding String name for for use with a parser.

This class is abstract since the method functionCall must be defined in a derived class.

As of 2.5.0, the class AbstractParser was made concrete and renamed BaseParser. At that time, its static inner classes were extracted and made standalone. This class was formerly named Procedure but the name AbstractFunction seemed more descriptive.

This class should not be confused with the class Function in edu.neu.ccs. The latter class is defined solely to collect several interfaces that are useful in classifying mathematical functions.

Field Summary

private int	arguments The number of arguments required by this function.
private String	name The name representing this function.

Constructor Summary

AbstractFunction(String name, int arguments)
Constructs a function with the given String name and given number of expected arguments.

Method Summary

int	arguments() Returns the number of arguments of this function.
void	checkValues(Object[] values) Throws a ParseExpection if: the values are null the length of values is not equal to arguments
void	checkValuesAsNumeric(Object[] values) Throws a ParseExpection if: the values are null the length of values is not equal to arguments the elements in values are not of type XNumber
void	checkValuesAsXObject(Object[] values) Throws a ParseExpection if: the values are null the length of values is not equal to arguments the elements in values are not of type XObject
abstract Object	functionCall(Object[] values) Applies the function using the provided array of argument values whose length must equal the number of arguments and returns its result.
static AbstractFunction	makeFourArg(String name, Function.FourArg f) Constructs an AbstractFunction object using the given name and the givenFunction.FourArg for its implementation.
static AbstractFunction	makeNoArg(String name, Function.NoArg f) Constructs an AbstractFunction object using the given name and the givenFunction.NoArg for its implementation.
static AbstractFunction	makeOneArg(String name, Function.OneArg f) Constructs an AbstractFunction object using the given name and the givenFunction.OneArg for its implementation.
static AbstractFunction	makeThreeArg(String name, Function.ThreeArg f) Constructs an AbstractFunction object using the given name and the givenFunction.ThreeArg for its implementation.
static AbstractFunction	makeTwoArg(String name, Function.TwoArg f) Constructs an AbstractFunction object using the given name and the givenFunction.TwoArg for its implementation.
String	name() Returns the String name of this function.

Methods inherited from class java.lang.Object

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

Field Detail

name

private String name

The name representing this function.

arguments

private int arguments

The number of arguments required by this function.

Constructor Detail

AbstractFunction

public AbstractFunction(String name,
                        int arguments)

Constructs a function with the given String name and given number of expected arguments.

The given name is trimmed prior to being used to define the function name.

Throws IllegalArgumentException if the name is not valid when tested by BaseParser.isPossibleIdentifier or if the given arguments value is negative.

Parameters:

name - the identifier for this function

arguments - the required number of arguments

Throws:

IllegalArgumentException

Method Detail

functionCall

public abstract Object functionCall(Object[] values)
                             throws ParseException

Applies the function using the provided array of argument values whose length must equal the number of arguments and returns its result.

Parameters:

values - the array of argument values

Throws:

ParseException

name

public final String name()

Returns the String name of this function.

arguments

public final int arguments()

Returns the number of arguments of this function.

checkValues

public final void checkValues(Object[] values)
                       throws ParseException

Throws a ParseExpection if:

• the values are null
• the length of values is not equal to arguments

Parameters:

values - the array of argument values

Throws:

ParseException

checkValuesAsXObject

public final void checkValuesAsXObject(Object[] values)
                                throws ParseException

Throws a ParseExpection if:

• the values are null
• the length of values is not equal to arguments
• the elements in values are not of type XObject

Parameters:

values - the array of argument values

Throws:

ParseException

checkValuesAsNumeric

public final void checkValuesAsNumeric(Object[] values)
                                throws ParseException

Throws a ParseExpection if:

• the values are null
• the length of values is not equal to arguments
• the elements in values are not of type XNumber

Parameters:

values - the array of argument values

Throws:

ParseException

makeNoArg

public static AbstractFunction makeNoArg(String name,
                                         Function.NoArg f)

Constructs an AbstractFunction object using the given name and the givenFunction.NoArg for its implementation.

Naturally, this function will require 0 arguments.

Parameters:

name - the function name to be used in a parser

f - the implementation function

Throws:

IllegalArgumentException

makeOneArg

public static AbstractFunction makeOneArg(String name,
                                          Function.OneArg f)

Constructs an AbstractFunction object using the given name and the givenFunction.OneArg for its implementation.

Naturally, this function will require 1 argument.

Parameters:

name - the function name to be used in a parser

f - the implementation function

Throws:

IllegalArgumentException

makeTwoArg

public static AbstractFunction makeTwoArg(String name,
                                          Function.TwoArg f)

Constructs an AbstractFunction object using the given name and the givenFunction.TwoArg for its implementation.

Naturally, this function will require 2 arguments.

Parameters:

name - the function name to be used in a parser

f - the implementation function

Throws:

IllegalArgumentException

makeThreeArg

public static AbstractFunction makeThreeArg(String name,
                                            Function.ThreeArg f)

Constructs an AbstractFunction object using the given name and the givenFunction.ThreeArg for its implementation.

Naturally, this function will require 3 arguments.

Parameters:

name - the function name to be used in a parser

f - the implementation function

Throws:

IllegalArgumentException

makeFourArg

public static AbstractFunction makeFourArg(String name,
                                           Function.FourArg f)

Constructs an AbstractFunction object using the given name and the givenFunction.FourArg for its implementation.

Naturally, this function will require 1 argument.

Parameters:

name - the function name to be used in a parser

f - the implementation function

Throws:

IllegalArgumentException