uk.ac.ed.epcc.webapp.jdbc.expr

Enum Operator

java.lang.Object

java.lang.Enum<Operator>

uk.ac.ed.epcc.webapp.jdbc.expr.Operator

All Implemented Interfaces:

java.io.Serializable, java.lang.Comparable<Operator>

public enum Operator
extends java.lang.Enum<Operator>

A supported binary operators on Numbers in an expression

Enum Constant Summary

Enum Constants

Enum Constant and Description
ADD
DIV
MUL
SUB

Method Summary

Modifier and Type	Method and Description
boolean	associates(Operator op) returns true iff: A this ( B op C) is the same as (A this B) op C
boolean	commutes() do you get the same result if the order of the arguments is swapped.
boolean	leftDistributive(Operator op) returns true iff: A this ( B op C ) is the same as (A this B) op ( A this C)
abstract java.lang.Number	operate(java.lang.Number a, java.lang.Number b)
boolean	rightDistributive(Operator op) returns true iff: ( A op B ) this C is the same as (A this C) op ( B this C)
abstract java.lang.String	text()
static Operator	valueOf(java.lang.String name) Returns the enum constant of this type with the specified name.
static Operator[]	values() Returns an array containing the constants of this enum type, in the order they are declared.

Methods inherited from class java.lang.Enum

clone, compareTo, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Enum Constant Detail

ADD

public static final Operator ADD

SUB

public static final Operator SUB

MUL

public static final Operator MUL

DIV

public static final Operator DIV

Method Detail

values

public static Operator[] values()

Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows:

for (Operator c : Operator.values())
    System.out.println(c);

Returns:

an array containing the constants of this enum type, in the order they are declared

valueOf

public static Operator valueOf(java.lang.String name)

Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)

Parameters:

name - the name of the enum constant to be returned.

Returns:

the enum constant with the specified name

Throws:

java.lang.IllegalArgumentException - if this enum type has no constant with the specified name

java.lang.NullPointerException - if the argument is null

operate

public abstract java.lang.Number operate(java.lang.Number a,
                                         java.lang.Number b)

text

public abstract java.lang.String text()

associates

public boolean associates(Operator op)

returns true iff: A this ( B op C) is the same as (A this B) op C

Parameters:

op -

Returns:

leftDistributive

public boolean leftDistributive(Operator op)

returns true iff: A this ( B op C ) is the same as (A this B) op ( A this C)

Parameters:

op -

Returns:

rightDistributive

public boolean rightDistributive(Operator op)

returns true iff: ( A op B ) this C is the same as (A this C) op ( B this C)

Parameters:

op -

Returns:

commutes

public boolean commutes()

do you get the same result if the order of the arguments is swapped.

Returns:

boolean true if operator commutes.