Class Grounder

java.lang.Object

edu.uky.cs.nil.sabre.comp.Grounder

public class Grounder
extends Object

Replaces all templates in a problem, such as fluents and events, with Logical.isGround() instances, such as ground fluents and ground events. Quantified expressions are also expanded and replaced with equivalent ground expressions.

For simplicity, elements of a problem can be defined with variables to indicate that they are defined for every possible value that the variable can stand for. For example, consider this problem:

entity Alice : character;
entity Bob : character;
property at(person : character) : location;

It defines a fluent whose name is "at" and with one parameter, a variable of type character. This concise definition actually defines two ground fluents:

• at(Alice)
• at(Bob)

A grounder is a compiler that replaces each of these template definitions with the many ground things they imply.

Author:

Stephen G. Ware

Method Summary

Modifier and Type	Method	Description
static CompiledProblem	compile(Problem problem, Worker.Status status)	Replaces all templates in a problem, such as fluents and events, with ground instances of those elements, such as compiled fluents and compiled events.

Methods inherited from class Object

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

Method Details

compile

public static CompiledProblem compile(Problem problem,
 Worker.Status status)

Replaces all templates in a problem, such as fluents and events, with ground instances of those elements, such as compiled fluents and compiled events.

Parameters:

problem - the original problem

status - a status to update while the compiler runs

Returns:

a compiled problem which contains only ground elements