Package com.mckoi.database

Class Operator

java.lang.Object

com.mckoi.database.Operator

All Implemented Interfaces:

java.io.Serializable

public abstract class Operator
extends java.lang.Object
implements java.io.Serializable

An operator for an expression.

Author:

Tobias Downer

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field	Description
static int	ALL	The ANY and ALL enumerator.
static int	ANY	The ANY and ALL enumerator.
static int	NONE	The ANY and ALL enumerator.

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	Operator(java.lang.String op)	Constructs the Operator.
protected	Operator(java.lang.String op, int precedence)
protected	Operator(java.lang.String op, int precedence, int set_type)

Method Summary

Modifier and Type	Method	Description
boolean	equals(java.lang.Object ob)
abstract TObject	eval(TObject ob1, TObject ob2, GroupResolver group, VariableResolver resolver, QueryContext context)
static Operator	get(java.lang.String op)	Returns an Operator with the given string.
Operator	getSubQueryForm(int type)	Returns the ANY or ALL form of this operator.
Operator	getSubQueryForm(java.lang.String type_str)	Same as above only it handles the type as a string.
Operator	inverse()	Returns the inverse operator of this operator.
boolean	is(java.lang.String given_op)	Returns true if this operator is equal to the operator string.
boolean	isCondition()
boolean	isLogical()
boolean	isMathematical()
boolean	isNot()
boolean	isNotInversible()	Returns true if this operator is not inversible.
boolean	isPattern()
boolean	isSubQuery()
boolean	isSubQueryForm(int type)	Given a parameter of either NONE, ANY, ALL or SINGLE, this returns true if this operator is of the given type.
int	precedence()
TType	returnTType()	The type of object this Operator evaluates to.
Operator	reverse()	Returns an Operator that is the reverse of this Operator.
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

NONE

public static final int NONE

The ANY and ALL enumerator.

See Also:

Constant Field Values

ANY

public static final int ANY

The ANY and ALL enumerator.

See Also:

Constant Field Values

ALL

public static final int ALL

The ANY and ALL enumerator.

See Also:

Constant Field Values

Constructor Detail

Operator

protected Operator(java.lang.String op)

Constructs the Operator.

Operator

protected Operator(java.lang.String op,
                   int precedence)

Operator

protected Operator(java.lang.String op,
                   int precedence,
                   int set_type)

Method Detail

is

public boolean is(java.lang.String given_op)

Returns true if this operator is equal to the operator string.

eval

public abstract TObject eval(TObject ob1,
                             TObject ob2,
                             GroupResolver group,
                             VariableResolver resolver,
                             QueryContext context)

precedence

public int precedence()

isCondition

public boolean isCondition()

isMathematical

public boolean isMathematical()

isPattern

public boolean isPattern()

isLogical

public boolean isLogical()

isNot

public boolean isNot()

isSubQuery

public boolean isSubQuery()

reverse

public Operator reverse()

Returns an Operator that is the reverse of this Operator. This is used for reversing a conditional expression. eg. 9 > id becomes id < 9.

isNotInversible

public boolean isNotInversible()

Returns true if this operator is not inversible.

inverse

public Operator inverse()

Returns the inverse operator of this operator. For example, = becomes <>, > becomes <=, AND becomes OR.

isSubQueryForm

public boolean isSubQueryForm(int type)

Given a parameter of either NONE, ANY, ALL or SINGLE, this returns true if this operator is of the given type.

getSubQueryForm

public Operator getSubQueryForm(int type)

Returns the ANY or ALL form of this operator.

getSubQueryForm

public Operator getSubQueryForm(java.lang.String type_str)

Same as above only it handles the type as a string.

returnTType

public TType returnTType()

The type of object this Operator evaluates to.

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

equals

public boolean equals(java.lang.Object ob)

Overrides:

equals in class java.lang.Object

get

public static Operator get(java.lang.String op)

Returns an Operator with the given string.