PDDLSharp 1.0.25

PDDLSharp

This is a package to make a PDDL parser, contextualiser, analyser, code generator and much more for C#. The parser is fully PDDL 2.2 compatible. The package can be found through Nuget or the Git package manager.

Parsers

There is a few parsers included in PDDLSharp, each of them will be explained in the subsections.

PDDL Parser

The PDDL Parser is the main part of PDDLSharp. Its a fully fledged parser that can parser up to PDDL 2.2 files.

A usage example of how to use the PDDL parser:

IErrorListener listener = new ErrorListener();
IParser<INode> parser = new PDDLParser(listener);
PDDLDecl decl = new PDDLDecl(
    parser.ParseAs<DomainDecl>("domain.pddl"),
    parser.ParseAs<ProblemDecl>("problem.pddl")
)

To parse a file as a specific PDDL object:

IErrorListener listener = new ErrorListener();
IParser<INode> parser = new PDDLParser(listener);
ActionDecl decl = parser.ParseAs<ActionDecl>("action-file.pddl");

To contextualise a domain/problem:

IErrorListener listener = new ErrorListener();
IParser<INode> parser = new PDDLParser(listener);
PDDLDecl decl = new PDDLDecl(
    parser.ParseAs<DomainDecl>("domain.pddl"),
    parser.ParseAs<ProblemDecl>("problem.pddl")
)
contextualiser.Contexturalise(decl);

To analyse a domain/problem (Note, the analyser will also contextualise the PDDL declaration, if it have not been contextualised):

IErrorListener listener = new ErrorListener();
IParser<INode> parser = new PDDLParser(listener);
IAnalyser analyser = new PDDLAnalyser(listener);
PDDLDecl decl = new PDDLDecl(
    parser.ParseAs<DomainDecl>("domain.pddl"),
    parser.ParseAs<ProblemDecl>("problem.pddl")
)
analyser.Analyse(decl);

Plan Parser

There is also a plan parser that can parse Fast Downward output plans.

IErrorListener listener = new ErrorListener();
IParser<ActionPlan> parser = new FastDownwardPlanParser(listener);
ActionPlan plan = parser.Parse("planFile");

Code Generators

PDDL Code Generator

To generate PDDL code from a PDDL declaration:

IErrorListener listener = new ErrorListener();
ICodeGenerator<INode> generator = new PDDLCodeGenerator(listener);
PDDLDecl decl = new PDDLDecl(...);
// If you want a "pretty" output, use:
// generator.Readable = true;
generator.Generate(decl.Domain, "domain.pddl");
generator.Generate(decl.Problem, "problem.pddl");

Plan Code Generator

To generate a Fast Downward plan from a ActionPlan declaration:

IErrorListener listener = new ErrorListener();
ICodeGenerator<ActionPlan> generator = new FastDownwardPlanGenerator(listener);
ActionPlan plan = new ActionPlan(...);
generator.Generate(plan, "planFile");

Simulators

State Space Simulator

There is a State Space Simulator included with PDDLSharp. This is a simulator that is capable of simulating the state changes for each action execution. If there are invalid arguments or type issues, the simulator will throw an exception.

PDDLDecl declaration = new PDDLDecl(...);
IStateSpaceSimulator simulator = new StateSpaceSimulator(declaration);
simulator.Step("actionName", "obj1", "obj2");

Plan Validator

There is a simple plan validator included in PDDLSharp. It is capable of taking in a ActionPlan and a PDDLDecl and verify if the given plan is even possible or not.

IErrorListener listener = new ErrorListener();
IParser<ActionPlan> parser = new FastDownwardPlanParser(listener);
ActionPlan plan = parser.Parse("planFile");

PDDLDecl declaration = new PDDLDecl(...);
IPlanValidator validator = new PlanValidator();
validator.Validate(plan, declaration);

The Validate(...) method returns true if the plan is valid, false otherwise.

Mutex Detector

There is a simple predicate mutex detector included in PDDLSharp. It is able to find simple action predicate mutexes. You just give it a PDDLDecl and it will try and find mutex predicates in it:

IErrorListener listener = new ErrorListener();
IParser<INode> parser = new PDDLParser(listener);
PDDLDecl decl = new PDDLDecl(...)

IMutexDetectors detector = new SimpleMutexDetector();
var mutexes = detector.FindMutexes(decl);

Supported Requirements

PDDLSharp supports a large set of requirements, all the way up to PDDL 2.2:

• STRIPS (:strips)
• Typing (:typing)
• Disjunctive Preconditions (:disjunctive-preconditions)
• Equality (:equality)
• Quantified Preconditions (:quantified-preconditions)
  • Existential Preconditions (:existential-preconditions)
  • Universal Preconditions (:universal-preconditions)
• Conditional Effects (:conditional-effects)
• Domain Axioms (:domain-axioms)
  • Subgoals Through Axioms (:subgoals-through-axioms)
  • Expression Evaluation (:expression-evaluation)
• ADL (:adl)
• Fluents (:fluents)
• Durative Actions (:durative-actions)
  • Durative Inequalities (:durative-inequalities)
  • Continuous Effects (:continuous-effects)
• Negative Preconditions (:negative-preconditions)
• Derived Predicates (:derived-predicates)
• Timed Initial Literals (:timed-initial-literals)
• Action Expansions (:action-expansions)
• Foreach Expansions (:forach-expansions)
• DAG Expansions (:dag-expansions)
• Safety Constraints (:safety-constraints)
• Open World (:open-world)
• True Negation (:true-negation)
• UCPOP (:ucpop)
• Constraints (:constraints)
• Preferences (:preferences)

Notes

The system tests uses the Downward Benchmark Set to test on. A repository with solved instances of the benchmarks are also used for the plan parsing and verification.