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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 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 <=>
.
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