Package org.qdl_lang.extensions.examples.basic

Class ExtrinsicVar

java.lang.Object

org.qdl_lang.extensions.examples.basic.ExtrinsicVar

All Implemented Interfaces:

Serializable, QDLVariable

public class ExtrinsicVar
extends Object
implements QDLVariable

An extrinsic (aka global, static in other langauges) variable in the workspace. Note that this is available after the module loads, hence before import. It has a value of 42, since, as we all know, that is the answer to everything.

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field	Description
static String	EX_NAME

Constructor Summary

Constructors

Constructor	Description
ExtrinsicVar()

Method Summary

Modifier and Type	Method	Description
String	getName()	The name of the variable.
Object	getValue()	The value.

Methods inherited from class java.lang.Object

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

Field Detail

EX_NAME

public static String EX_NAME

Constructor Detail

ExtrinsicVar

public ExtrinsicVar()

Method Detail

getName

public String getName()

Description copied from interface: QDLVariable

The name of the variable. This may be a simple name for a scalar, like "a", or it may represent a stem, like "a." (yes, include the period for a stem). You may even set specific stem values by passing in the indexed stem, e.g. "a.3". It might make sense, if e.g. you had a stem that modelled String Theory where the stem is an 11 dimensional object that required a great deal of computation only do-able in Java (such as a specialized scientific library which would be a hugely complex job to expose in QDL). You could then just set each component of the stem.

A note on extrinsic values

Extrinsic values start with a $$ (VariableState.EXTRINSIC_MARKER) and when the module is loaded, these are put into the workspace -- not at import. This lets you have module constants in advance of configuration the module.

Specified by:

getName in interface QDLVariable

Returns:

getValue

public Object getValue()

Description copied from interface: QDLVariable

The value. The basic Java types that QDL knows are Boolean, String, Long, BigDecimal, edu.uiuc.ncsa.qdl.variables.QDLSet and QDLStem. Again, this class sets the value and is used to create a single instance of this variable in the workspace, so there should be no state to manage in this class -- just return the value it should have.

Specified by:

getValue in interface QDLVariable

Returns: