Package nz.org.riskscape.engine.function

Class NullSafeFunction

java.lang.Object

nz.org.riskscape.engine.function.NullSafeFunction

All Implemented Interfaces:

AutoCloseable, RiskscapeFunction, UntypedFunction

public class NullSafeFunction
extends Object
implements RiskscapeFunction

A RiskscapeFunction that wraps another one to short-circuit the target function to return null if any of the args are null.

Field Summary

Fields inherited from interface nz.org.riskscape.engine.function.RiskscapeFunction

BUILT_IN

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	NullSafeFunction(RiskscapeFunction target, List<Type> argumentTypes, Type returnType, boolean[] notNullableIndices)

Method Summary

Modifier and Type	Method	Description
Object	call(List<Object> args)	Execute the function with the given arguments.
void	close()	Clean up any resources that were allocated with this function.
List<Type>	getArgumentTypes()
boolean[]	getNotNullableIndices()	for each argument, records true if the original receiver is not nullable
Type	getReturnType()
RiskscapeFunction	getTarget()
String	toString()
static RiskscapeFunction	wrap(RiskscapeFunction target)	Wrap the given target function in a null-safe version.
static RiskscapeFunction	wrapIgnoringArgs(RiskscapeFunction target)	Wrap the given target function in a null-safe version.

Methods inherited from class java.lang.Object

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

Methods inherited from interface nz.org.riskscape.engine.function.RiskscapeFunction

builtin, getAggregationFunction, getArguments, getOverloaded, getRealizable, getTypesFromArguments, identified, identified, isA, setProblemReporter, validate

Constructor Details

NullSafeFunction

protected NullSafeFunction(RiskscapeFunction target,
 List<Type> argumentTypes,
 Type returnType,
 boolean[] notNullableIndices)

Method Details

wrap

public static RiskscapeFunction wrap(RiskscapeFunction target)

Wrap the given target function in a null-safe version. If any of the target function's arguments are not nullable, then the resulting function will be a NullSafeFunction with those arguments that are not marked as nullable being wrapped and applying the null-short-circuit behaviour when the function is called

wrapIgnoringArgs

public static RiskscapeFunction wrapIgnoringArgs(RiskscapeFunction target)

Wrap the given target function in a null-safe version.

call

public Object call(List<Object> args)

Description copied from interface: UntypedFunction

Execute the function with the given arguments.

Specified by:

call in interface UntypedFunction

Parameters:

args - list of arguments to the function that should conform to the types in ArgumentList.getArgumentTypes()

close

public void close()

Description copied from interface: UntypedFunction

Clean up any resources that were allocated with this function. This can include large objects, so that any memory used can be reclaimed.

See Realized for more information on the life-cycle of executable pipeline objects.

Note that there is no standard mechanism for cleaning up resources allocated to functions that realize lambda expressions - the closing of any RealizedExpressions or related objects must be done by the function when it's closed. This is probably something that should be addressed once some standard patterns have been established for the implementation of lambda-accepting functions.

Specified by:

close in interface AutoCloseable

Specified by:

close in interface UntypedFunction

toString

public String toString()

Overrides:

toString in class Object

getTarget

public RiskscapeFunction getTarget()

getArgumentTypes

public List<Type> getArgumentTypes()

Specified by:

getArgumentTypes in interface RiskscapeFunction

Returns:

the types that this function expects

getReturnType

public Type getReturnType()

Specified by:

getReturnType in interface RiskscapeFunction

Returns:

the type that this function should return

getNotNullableIndices

public boolean[] getNotNullableIndices()

for each argument, records true if the original receiver is not nullable