Package com.singularsys.jep.misc.nullwrapper

Package to allow the treatment of null values which propagate up through evaluation so that null op anything will be null for any operator.

See:
Description

Class Summary

NullWrapperBinary	Null wrapped version of a binary function.
NullWrapperFunctionFactory	A static factory to create the appropriate type of wrapped function.
NullWrapperFunctionTable	A function table which wraps all the functions in an existing table.
NullWrapperNary	Wrap an NaryFunction with a new function so that if any argument is null null is returned.
NullWrapperNaryBinary	Wrap a NaryBinaryFunction so that if any argument is null then null is returned.
NullWrapperPfmc	Wrap a general PostfixMathCommand so that if any argument is null the function will return null.
NullWrapperUnary	Null wrapped version of a unary function.
NullWrappingOperatorTable	An operator table where the operators generally return null if either argument is null.

Enum Summary

NullWrappingOperatorTable.NullWrapperOperators

Package com.singularsys.jep.misc.nullwrapper Description

Package to allow the treatment of null values which propagate up through evaluation so that null op anything will be null for any operator. The package works by wrapping existing operators and functions in new operators and functions which will propagate null values.

To set up this functionality use

jep.setComponent(new NullWrappingOperatorTable((OperatorTable2) jep.getOperatorTable(),true));
jep.setComponent(new NullWrapperFunctionTable(jep.getFunctionTable()));
jep.setComponent(new StandardConfigurableParser());
((FastEvaluator) jep.getEvaluator()).setTrapNullValues(false);

This will include the standard set of operators and functions. The StandardConfigurableParser is needed to add the Null-safe equals operator <=>.