Package org.metricshub.jawk.ext

Class ExtensionFunction

java.lang.Object

org.metricshub.jawk.ext.ExtensionFunction

All Implemented Interfaces:

Serializable

public final class ExtensionFunction
extends Object
implements Serializable

Metadata describing a single annotated extension function.

See Also:

• Serialized Form

Method Summary

Modifier and Type	Method	Description
int[]	collectAssocArrayIndexes(int argCount)	Collects the indexes of arguments that must be associative arrays for a call with the supplied argument count.
boolean	expectsAssocArray(int index)	Indicates whether the parameter at the supplied index must be an associative array.
int	getArity()	Returns the minimum number of arguments required to invoke the function.
Class<? extends AbstractExtension>	getDeclaringType()	Returns the extension type that declares the underlying Java method.
String	getExtensionClassName()	Returns the fully-qualified class name of the declaring extension.
String	getKeyword()	Returns the Awk keyword mapped to this extension function.
Object	invoke(AbstractExtension target, Object[] args)	Invokes the underlying Java method on the supplied target instance.
void	verifyArgCount(int argCount)	Verifies that the provided argument count satisfies the arity constraints encoded in the metadata.

Methods inherited from class java.lang.Object

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

Method Details

getKeyword

public String getKeyword()

Returns the Awk keyword mapped to this extension function.

Returns:

the keyword exposed by the annotated method

getDeclaringType

public Class<? extends AbstractExtension> getDeclaringType()

Returns the extension type that declares the underlying Java method.

Returns:

declaring AbstractExtension subtype

getExtensionClassName

public String getExtensionClassName()

Returns the fully-qualified class name of the declaring extension.

Returns:

extension class name

getArity

public int getArity()

Returns the minimum number of arguments required to invoke the function.

Returns:

required argument count before considering varargs

expectsAssocArray

public boolean expectsAssocArray(int index)

Indicates whether the parameter at the supplied index must be an associative array.

Parameters:

index - zero-based parameter index

Returns:

true when the parameter must be an associative array

Throws:

IndexOutOfBoundsException - when the index exceeds the parameter count

collectAssocArrayIndexes

public int[] collectAssocArrayIndexes(int argCount)

Collects the indexes of arguments that must be associative arrays for a call with the supplied argument count. Vararg positions are included when the vararg parameter requires associative arrays.

Parameters:

argCount - number of arguments supplied by the caller

Returns:

indexes of arguments that must be associative arrays

invoke

public Object invoke(AbstractExtension target,
 Object[] args)

Invokes the underlying Java method on the supplied target instance.

Parameters:

target - extension instance to receive the call

args - arguments evaluated by the interpreter

Returns:

result of the Java invocation

Throws:

IllegalAwkArgumentException - when the arguments violate the metadata

IllegalStateException - when reflection cannot invoke the method

verifyArgCount

public void verifyArgCount(int argCount)

Verifies that the provided argument count satisfies the arity constraints encoded in the metadata.

Parameters:

argCount - number of arguments the caller supplied

Throws:

IllegalAwkArgumentException - when the count violates the signature