com.waveset.expression
Class ExFunction.f_isnull
java.lang.Object
com.waveset.expression.ExNode
com.waveset.expression.ExFunction.f_isnull
- All Implemented Interfaces:
- com.sun.idm.debugger.common.Locatable
- Enclosing class:
- ExFunction
- public static class ExFunction.f_isnull
- extends ExNode
The function node for the <isnull> expression.
The isnull expression returns the integer 1 if the value of
its single subexpression is logically null, and otherwise
returns 0.
Nullness is defined by the ExValue.isNull method.
A null is the absense of value, note that an empty string is NOT null.
Methods inherited from class com.waveset.expression.ExNode |
addChild, addChildren, addCommonAttributes, beginTrace, clearOwner, endTrace, eval, evalChild, evalChildToObject, evalChildToString, evalToBoolean, evalToInt, evalToObject, evalToString, getBindingCount, getChild, getChildren, getDecoration, getHiddenVariable, getLocation, getOwner, getParent, isLiteral, parseCommonAttributes, parseXml, postProcess, removeChild, resolveFunction, resolveVariable, setBindingCount, setChildren, setDecoration, setEnvironment, setLocation, setOwner, setOwner, setParent, toXml, toXml, toXml, toXmlAttributes, toXmlChildren |
Methods inherited from class java.lang.Object |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
ExFunction.f_isnull
public ExFunction.f_isnull()
getFunctionName
public java.lang.String getFunctionName()
- Description copied from class:
ExNode
- Nodes representing functions must have a name.
This name is used in the formatting of default trace
messages and the default XML rendering.
If a node doesn't have a name for some reason, or needs
more control over the trace messges and XML, they
must overload beginTrace, endTrace, and toXml below.
- Specified by:
getFunctionName
in class ExNode
evalInternal
protected ExValue evalInternal(ExState state)
throws WavesetException
- Description copied from class:
ExNode
- Abstract evaluation method all nodes must have. Implementations of
evalInternal need not (and should not) perform any tracing/breakpoints.
This is all handled by the calling method eval.
- Specified by:
evalInternal
in class ExNode
- Throws:
WavesetException