Knowledge Bases

v1.0

groupID

at.tugraz.ist.ase.hiconfit

artifactID

kb

hiconfit-core allows to represent knowledge bases as Constraint Satisfaction Problems. kb provides classes managing a (Choco) CSP representation of a knowledge base. Besides, it also offers two core classes representing user requirements and solutions of a configurator.

Feature model is a type of knowledge representation. For more details related to what hiconfit-core supports for feature models, we refer to Feature models.

TBD

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Table of Contents

1. What kb provides
2. How-tos
   1. Encoding your own knowledge base
   2. Creating a FMKB object for a feature model read from a file
   3. Creating and using an object of FMKB, PCKB, RenaultKB, and CameraKB
   4. Implementing a new assignment translator
   5. How to for Utility functions

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What kb provides

kb provides the following features:

• An abstract KB class managing variables (Variable), variable domains (Domain), and constraints (Constraint) of a knowledge base/feature model.
• Two types of variables:
  1. Integer variables (IntVariable)
  2. Boolean variables (BoolVariable)
• Two interfaces specifying the behaviors of the knowledge base:
  1. IIntVarKB returns Choco’s IntVar
  2. IBoolVarKB returns Choco’s BoolVar
• Constraint manages corresponding Choco constraints, as well as their negation.
• Two utility builders IntVarConstraintBuilder and BoolVarConstraintBuilder help to build a Constraint object from a list of Choco constraints.
• Already encoded knowledge bases:
  1. FMKB - an implementation for a CSP representation of a feature model. The input of FMKB is a FeatureModel object. So you can use FMKB for any feature models you have, i.e., no need to implement a specific KB class for an individual feature model. FMKB uses BoolVariables, and conforms IBoolVarKB. FMKB uses BoolVarConstraintBuilder to build constraints.
  2. PCKB - an implementation of PC Configuration Knowledge Base. PCKB uses IntVariables, and conforms IIntVarKB. PCKB uses IntVarConstraintBuilder to build constraints.
  3. RenaultKB - an implementation of Renault Configuration Knowledge Base. RenaultKB uses IntVariables, and conforms IIntVarKB. RenaultKB uses IntVarConstraintBuilder to build constraints.
  4. CameraKB - an implementation of Camera Configuration Knowledge Base. CameraKB uses IntVariables, and conforms IIntVarKB. CameraKB uses IntVarConstraintBuilder to build constraints.
• Assignment class represents an assignment of a value to a variable. It could represent a CSP assignment or a SAT clause, e.g., F1 = true. Besides, it could represent a preference of a user requirement, e.g., Modell = limousine.
• Two interfaces IAssignmentsTranslatable and ILogOpCreatable specifying the behaviors of a translator from an assignment to Choco constraints. FMAssignmentsTranslator is a specific translator for feature model’s assignments.
• Utility functions for variables (VariableUtils) and constraints (ConstraitUtils)

Negative constraints are used in the algorithms WipeOutR_T, WipeOutR_FM.

How-tos

Encoding your own knowledge base

You can implement your knowledge base by inheriting the KB class.

Examples

PCKB, FMKB

Creating a FMKB object for a feature model read from a file

The following code shows how to create a FMKB object for a feature model which is parsed from a file.

File fileFM = new File("src/test/resources/smartwatch.sxfm");

// create a parser for the given file
@Cleanup("dispose")
FeatureModelParser<Feature, AbstractRelationship<Feature>, CTConstraint>
    parser = FMParserFactory.getInstance().getParser(fileFM.getName());

// parse the feature model file
FeatureModel<Feature, AbstractRelationship<Feature>, CTConstraint>
    fm = parser.parse(fileFM);

// create an FMKB object with the given feature model and requires to generate also the negative constraints
FMKB<Feature, AbstractRelationship<Feature>, CTConstraint>
    kb = new FMKB<>(fm, true);

For more examples related to feature models, we refer to [Feature model].

Creating and using an object of FMKB, PCKB, RenaultKB, and CameraKB

Examples

KBStatistics, ‘FMKBTest’s, ‘PCKBTest’, ‘RenaultKBTest’, and ‘CameraKBTest’

Implementing a new assignment translator

Example

FMAssignmentsTranslator

How to for Utility functions

TBD