org.jsimpledb.parse.expr

Class ValueValue

java.lang.Object

org.jsimpledb.parse.expr.AbstractValue

org.jsimpledb.parse.expr.AbstractLValue

org.jsimpledb.parse.expr.ValueValue

All Implemented Interfaces:

LValue, Value

public class ValueValue
extends AbstractLValue

A Value that holds a reference to some other Value.

Field Summary

Fields inherited from interface org.jsimpledb.parse.expr.Value

EQ, GT, LT, NO_VALUE

Constructor Summary

Constructors

Constructor and Description
ValueValue() Constructor.
ValueValue(Value value) Constructor.

Method Summary

Modifier and Type	Method and Description
Object	get(ParseSession session) Evaluate this value within the given context.
Class<?>	getType(ParseSession session) Get the type of this value without evaluating it.
void	set(ParseSession session, Value value) Make assignment to this instance.

Methods inherited from class org.jsimpledb.parse.expr.AbstractValue

add, and, asLValue, checkBoolean, checkIntegral, checkNotNull, checkNumeric, checkType, compare, divide, invert, lshift, mod, multiply, negate, or, rshift, subtract, urshift, xor, xxcrement

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.jsimpledb.parse.expr.Value

add, and, asLValue, checkBoolean, checkIntegral, checkNotNull, checkNumeric, checkType, compare, divide, invert, lshift, mod, multiply, negate, or, rshift, subtract, urshift, xor, xxcrement

Constructor Detail

ValueValue

public ValueValue()

Constructor.

This instance will have no initial value; until one is set, get() will throw an exception.

ValueValue

public ValueValue(Value value)

Constructor.

Parameters:

value - initial value, or null for none

Method Detail

get

public Object get(ParseSession session)

Description copied from interface: Value

Evaluate this value within the given context.

Normally this method should only be invoked once, and the result cached, because evaluation could have side effects.

Parameters:

session - parse session

Returns:

the evaluated result

getType

public Class<?> getType(ParseSession session)

Description copied from interface: Value

Get the type of this value without evaluating it.

This should perform a best-effort attempt to determine the type, but should not invoke get(). If the type is unknown, Object.class should be returned.

Specified by:

getType in interface Value

Overrides:

getType in class AbstractValue

Parameters:

session - parse session

Returns:

the expected type of the evaluated result

set

public void set(ParseSession session,
                Value value)

Description copied from interface: LValue

Make assignment to this instance.

Parameters:

session - parse session

value - new value for this instance