xtc.type
Class Constant

java.lang.Object
  xtc.type.Constant

public class Constant
extends java.lang.Object

Representation of a type's constant value. A constant value may be one of the following:

• A boxed byte, short, int, or long.
• A big integer.
• A boxed char.
• A string.
• A Reference.

This class treats a zero as a null value. It also treats a zero as a boolean false value and any other number as a boolean true value.

Version:

$Revision: 1.11 $

Author:

Robert Grimm

Nested Class Summary

static class

Constant.Kind The kind.

Constructor Summary

Constant(java.lang.Object value)
Create a new constant value.

Method Summary

java.math.BigInteger	bigIntValue() Get this constant's value as a big integer.
double	doubleValue() Get this constant's value as a double.
Constant.Kind	getKind() Get this constant's kind.
java.lang.Object	getValue() Get this constant's value.
boolean	isNull() Determine whether this constant represents a null value.
boolean	isNumber() Determine whether this constant's value can be treated as a number.
boolean	isReference() Determine whether this constant's value is a reference.
boolean	isString() Determine whether this constant's value is a string.
boolean	isTrue() Determine whether this constant represents a boolean true value.
long	longValue() Get this constant's value as a long.
Reference	refValue() Get this constant's value as a reference.
java.lang.String	stringValue() Get this constant's value as a string.

Methods inherited from class java.lang.Object

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

Constructor Detail

Constant

public Constant(java.lang.Object value)

Create a new constant value.

Parameters:

value - The value.

Throws:

java.lang.IllegalArgumentException - Signals an invalid value.

Method Detail

getKind

public Constant.Kind getKind()

Get this constant's kind.

Returns:

The kind.

isNumber

public boolean isNumber()

Determine whether this constant's value can be treated as a number.

Returns:

true if this constant's kind is an integer, big integer, double, or character.

isString

public boolean isString()

Determine whether this constant's value is a string.

Returns:

true if this constant's value is a string.

isReference

public boolean isReference()

Determine whether this constant's value is a reference.

Returns:

true if this constant's value is a reference.

getValue

public java.lang.Object getValue()

Get this constant's value.

Returns:

The value.

longValue

public long longValue()

Get this constant's value as a long.

Returns:

The value as a long.

Throws:

java.lang.IllegalStateException - Signals that this constant cannot be converted to a long.

bigIntValue

public java.math.BigInteger bigIntValue()

Get this constant's value as a big integer.

Returns:

The value as a big integer.

Throws:

java.lang.IllegalStateException - Signals that this constant cannot be converted to a big integer.

doubleValue

public double doubleValue()

Get this constant's value as a double.

Returns:

The value as a double.

Throws:

java.lang.IllegalStateException - Signals that this constant cannot be converted to a double.

refValue

public Reference refValue()

Get this constant's value as a reference.

Returns:

The value as a reference.

Throws:

java.lang.IllegalStateException - Signals that this constant is not a reference.

stringValue

public java.lang.String stringValue()

Get this constant's value as a string.

Returns:

The value as a string.

Throws:

java.lang.IllegalStateException - Signals that this constant is not a string.

isTrue

public boolean isTrue()

Determine whether this constant represents a boolean true value.

Returns:

true if this constant represents true.

isNull

public boolean isNull()

Determine whether this constant represents a null value.

Returns:

true if this constant represents null.