net.objecthunter.exp4j.operator

Class Operator

java.lang.Object

net.objecthunter.exp4j.operator.Operator

public abstract class Operator
extends Object

Class representing operators that can be used in an expression

Field Summary

Fields

Modifier and Type	Field and Description
static char[]	ALLOWED_OPERATOR_CHARS The set of allowed operator chars
protected boolean	leftAssociative
protected int	numOperands
protected int	precedence
static int	PRECEDENCE_ADDITION The precedence value for the addition operation
static int	PRECEDENCE_DIVISION The precedence value for the division operation
static int	PRECEDENCE_MODULO The precedence value for the modulo operation
static int	PRECEDENCE_MULTIPLICATION The precedence value for the multiplication operation
static int	PRECEDENCE_POWER The precedence value for the power operation
static int	PRECEDENCE_SUBTRACTION The precedence value for the subtraction operation
static int	PRECEDENCE_UNARY_MINUS The precedence value for the unary minus operation
static int	PRECEDENCE_UNARY_PLUS The precedence value for the unary plus operation
protected String	symbol

Constructor Summary

Constructors

Constructor and Description
Operator(String symbol, int numberOfOperands, boolean leftAssociative, int precedence) Create a new operator for use in expressions

Method Summary

Methods

Modifier and Type	Method and Description
abstract double	apply(double... args) Apply the operation on the given operands
int	getNumOperands() Get the number of operands
int	getPrecedence() Check the precedence value for the operator
String	getSymbol() Get the operator symbol
static boolean	isAllowedOperatorChar(char ch) Check if a character is an allowed operator char
boolean	isLeftAssociative() Check if the operator is left associative

Methods inherited from class java.lang.Object

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

Field Detail

PRECEDENCE_ADDITION

public static final int PRECEDENCE_ADDITION

The precedence value for the addition operation

See Also:

Constant Field Values

PRECEDENCE_SUBTRACTION

public static final int PRECEDENCE_SUBTRACTION

The precedence value for the subtraction operation

See Also:

Constant Field Values

PRECEDENCE_MULTIPLICATION

public static final int PRECEDENCE_MULTIPLICATION

The precedence value for the multiplication operation

See Also:

Constant Field Values

PRECEDENCE_DIVISION

public static final int PRECEDENCE_DIVISION

The precedence value for the division operation

See Also:

Constant Field Values

PRECEDENCE_MODULO

public static final int PRECEDENCE_MODULO

The precedence value for the modulo operation

See Also:

Constant Field Values

PRECEDENCE_POWER

public static final int PRECEDENCE_POWER

The precedence value for the power operation

See Also:

Constant Field Values

PRECEDENCE_UNARY_MINUS

public static final int PRECEDENCE_UNARY_MINUS

The precedence value for the unary minus operation

See Also:

Constant Field Values

PRECEDENCE_UNARY_PLUS

public static final int PRECEDENCE_UNARY_PLUS

The precedence value for the unary plus operation

See Also:

Constant Field Values

ALLOWED_OPERATOR_CHARS

public static final char[] ALLOWED_OPERATOR_CHARS

The set of allowed operator chars

numOperands

protected final int numOperands

leftAssociative

protected final boolean leftAssociative

symbol

protected final String symbol

precedence

protected final int precedence

Constructor Detail

Operator

public Operator(String symbol,
        int numberOfOperands,
        boolean leftAssociative,
        int precedence)

Create a new operator for use in expressions

Parameters:

symbol - the symbol of the operator

numberOfOperands - the number of operands the operator takes (1 or 2)

leftAssociative - set to true if the operator is left associative, false if it is right associative

precedence - the precedence value of the operator

Method Detail

isAllowedOperatorChar

public static boolean isAllowedOperatorChar(char ch)

Check if a character is an allowed operator char

Parameters:

ch - the char to check

Returns:

true if the char is allowed an an operator symbol, false otherwise

isLeftAssociative

public boolean isLeftAssociative()

Check if the operator is left associative

Returns:

true os the operator is left associative, false otherwise

getPrecedence

public int getPrecedence()

Check the precedence value for the operator

Returns:

the precedence value

apply

public abstract double apply(double... args)

Apply the operation on the given operands

Parameters:

args - the operands for the operation

Returns:

the calculated result of the operation

getSymbol

public String getSymbol()

Get the operator symbol

Returns:

the symbol

getNumOperands

public int getNumOperands()

Get the number of operands

Returns:

the number of operands