de.learnlib.mapper.api

Interface Mapper<AI,AO,CI,CO>

Type Parameters:

AI - abstract input symbol type.

AO - abstract output symbol type.

CI - concrete input symbol type.

CO - concrete output symbol type.

All Known Implementing Classes:

AbstractMapper, SimplePOJODataMapper, StringMapper

public interface Mapper<AI,AO,CI,CO>

A mapper that lifts a SUL from an "abstract" to a "concrete" level.

The notion of "abstract" and "concrete" is not universally defined, and mostly depends on the chosen perspective. Generally speaking, the point of a Mapper<AI,AO,CI,CO> is to translate a SUL<CI,CO> into a SUL<AI,AO>, and additionally provide facilities to map exceptions occurring at the concrete level to symbols at the abstract level.

The class Mappers provides static utility functions for manipulating mappers.

Mappers, like SULs, may be forkable. The requirements and semantics of fork() are basically the same as set forth for SUL.fork(). Stateless mappers (e.g., with empty pre() and post() implementations), should always be forkable, and fork() may just return this. Stateful mappers may require more sophisticated fork logic, but in general it should be possible to fork them as well.

Note: despite the above recommendation that mappers should almost always be forkable, the default implementations of canFork() and fork() indicate non-forkability for backwards compatibility reasons.

Author:

Malte Isberner

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static class	Mapper.MappedException<AO>

Method Summary

Modifier and Type	Method and Description
default boolean	canFork() Checks whether it is possible to fork this mapper.
default Mapper<AI,AO,CI,CO>	fork() Forks this mapper, i.e., returns a mapper that behaves in exactly the same way as this mapper, but allows for being used independently of this mapper.
CI	mapInput(AI abstractInput) Method that maps an abstract input to a corresponding concrete input.
AO	mapOutput(CO concreteOutput) Method that maps a concrete output to a corresponding abstract output.
Mapper.MappedException<? extends AO>	mapUnwrappedException(RuntimeException exception) Maps an unwrapped RuntimeException to an abstract output symbol, or rethrows it if it is unmappable.
Mapper.MappedException<? extends AO>	mapWrappedException(SULException exception) Maps a wrapped SULException to an abstract output symbol, or rethrows it if it is unmappable.
void	post() Method that is invoked after all translation steps on a word are performed.
void	pre() Method that is invoked before any translation steps on a word are performed.

Method Detail

pre

void pre()

Method that is invoked before any translation steps on a word are performed.

post

void post()

Method that is invoked after all translation steps on a word are performed.

mapInput

CI mapInput(AI abstractInput)

Method that maps an abstract input to a corresponding concrete input.

Parameters:

abstractInput - the abstract input

Returns:

the concrete input

mapOutput

AO mapOutput(CO concreteOutput)

Method that maps a concrete output to a corresponding abstract output.

Parameters:

concreteOutput - the concrete output

Returns:

the abstract output

mapWrappedException

Mapper.MappedException<? extends AO> mapWrappedException(SULException exception)
                                                  throws SULException

Maps a wrapped SULException to an abstract output symbol, or rethrows it if it is unmappable.

Parameters:

exception - the wrapped exception that was thrown

Returns:

the concrete output symbol the exception was mapped to, if applicable

Throws:

SULException - if the exception cannot be mapped, or if a new exception occurs while trying to map the given exception

mapUnwrappedException

Mapper.MappedException<? extends AO> mapUnwrappedException(RuntimeException exception)
                                                    throws SULException,
                                                           RuntimeException

Maps an unwrapped RuntimeException to an abstract output symbol, or rethrows it if it is unmappable.

Parameters:

exception - the runtime exception that was thrown

Returns:

the concrete output symbol the exception was mapped to, if applicable

Throws:

SULException - if a new exception occurs while trying to map the given exception

RuntimeException - if the given exception cannot be mapped, or if a new exception occurs while trying to map the given exception

canFork

default boolean canFork()

Checks whether it is possible to fork this mapper.

Returns:

true if this mapper can be forked, false otherwise.

fork

@Nonnull
default Mapper<AI,AO,CI,CO> fork()
                                   throws UnsupportedOperationException

Forks this mapper, i.e., returns a mapper that behaves in exactly the same way as this mapper, but allows for being used independently of this mapper.

If canFork() returned false, this method must throw an UnsupportedOperationException. Otherwise, it must return a non-null object representing the fork of this mapper.

Returns:

a fork of this mapper (for stateless mappers, generally this should be returned)

Throws:

UnsupportedOperationException - if this mapper is not forkable