Programmatic implementation¶
The following figure provides some details about classes and interfaces of the implementation.
Base module implementation¶
Each component in the Base module has been implemented by means of abstract class, generic class or interface that will specialize in the following packages.
In particular, the Handler
class collects InputProgram
and OptionDescriptor
objects communicated by the user.
For what the asynchronous mode is concerned, the class Service
depends from the interface CallBack
, since once the reasoning service has terminated, the result of the computation is returned back via a class CallBack
.
Platforms module implementation¶
In order to support a new platform, the Handler
and Service
components must be adapted.
For the desktop platform we developed a DesktopHandler
and a DesktopService
, which generalizes the usage of a solver on the desktop platform, allowing both synchronous and asynchronous execution modes.
Languages module implementation¶
This module includes specific classes for the management of input and output to ASP, Datalog and PDDL solvers.
The Mapper
component of the Languages module is implemented via a Mapper
class, that allows to translate input and output into Programmatic objects.
Such translations are guided by ANTLR4 library and Programmatic Attributes, a form of metadata that mark Programmatic code and provide information that is not part of the program itself: they have no direct effect on the operation of the code they annotate.
In our setting, we make use of such features so that it is possible to translate facts into strings and vice-versa via two custom attributes, defined according to the following syntax:
[Id(string_name)] : the target must be a class, and defines the predicate name (in the ASP/Datalog case) and the action name (in the PDDL case) the class is mapped to;
[Param(integer_position)] : the target must be a field of a class annotated via [Id(string_name)], and defines the term (and its position) in the atom (in the ASP/Datalog case) and in the action (in the PDDL case) the field is mapped to.
By means of the Programmatic Reflection mechanism, attributes are examined at runtime, and taken into account to properly define the translation.
If the classes intended for the translation are not annotated or not correctly annotated, an exception is raised.
In addition to the Mapper
, this module features three sub-modules which are more strictly related to ASP, Datalog and PDDL.
Specialization module implementation¶
The classes DLVAnswerSets
, DLV2AnswerSets
, ClingoAnswerSets
, DLVHEXAnswerSets
implement specific extensions of the AnswerSets
class, the SPDPlan
class extends Plan
, while IDLVMinimalModels
extends MinimalModels
. These classes are in charge of manipulating the output of the respective solvers (e.g. IDLV).
Moreover, this module can contain classes extending OptionDescriptor
to implement specific options of the solver at hand.
Class Diagram¶
A complete UML Class Diagram is available here.
For further information, contact embasp@mat.unical.it or visit our website.