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Diffstat (limited to 'utils/PDDLtoSANetTranslator/PDDLParser/src/pddl4j/exp/Exp.java')
| -rw-r--r-- | utils/PDDLtoSANetTranslator/PDDLParser/src/pddl4j/exp/Exp.java | 254 |
1 files changed, 254 insertions, 0 deletions
diff --git a/utils/PDDLtoSANetTranslator/PDDLParser/src/pddl4j/exp/Exp.java b/utils/PDDLtoSANetTranslator/PDDLParser/src/pddl4j/exp/Exp.java new file mode 100644 index 00000000000..1c6858e1124 --- /dev/null +++ b/utils/PDDLtoSANetTranslator/PDDLParser/src/pddl4j/exp/Exp.java @@ -0,0 +1,254 @@ +/* + * Copyright Dept. of Mathematics & Computer Science Univ. Paris-Descartes + * + * This software is governed by the CeCILL license under French law and + * abiding by the rules of distribution of free software. You can use, + * modify and/ or redistribute the software under the terms of the CeCILL + * license as circulated by CEA, CNRS and INRIA at the following URL + * "http://www.cecill.info". + * + * As a counterpart to the access to the source code and rights to copy, + * modify and redistribute granted by the license, users are provided only + * with a limited warranty and the software's author, the holder of the + * economic rights, and the successive licensors have only limited + * liability. + * + * In this respect, the user's attention is drawn to the risks associated + * with loading, using, modifying and/or developing or reproducing the + * software by the user in light of its specific status of free software, + * that may mean that it is complicated to manipulate, and that also + * therefore means that it is reserved for developers and experienced + * professionals having in-depth computer knowledge. Users are therefore + * encouraged to load and test the software's suitability as regards their + * requirements in conditions enabling the security of their systems and/or + * data to be ensured and, more generally, to use and operate it in the + * same conditions as regards security. + * + * The fact that you are presently reading this means that you have had + * knowledge of the CeCILL license and that you accept its terms. + */ + +package pddl4j.exp; + +import java.io.Serializable; +import java.util.Map; +import java.util.Set; + +import pddl4j.exp.term.Substitution; +import pddl4j.exp.term.Term; +import pddl4j.exp.term.Variable; + +/** + * This interface is implemented by all expression of the PDDL language. + * + * @author Damien Pellier + * @version 1.0 + */ +public interface Exp extends Serializable, Cloneable { + + /** + * Returns the id of the expression. + * + * @return the id of the expression. + */ + ExpID getExpID(); + + /** + * Returns <code>true</code> if the expression is ground. + * + * @return <code>true</code> if the expression is ground; + * <code>false</code>otherwise. + */ + boolean isGround(); + + /** + * Returns <code>true</code> if this expression is equal to an other + * object, i.e., if the object is a not null instance of the class of the + * expression and both expressions have the same content. + * + * @param obj the reference object with which to compare. + * @return <code>true</code> if this expression is equal to an other + * object; <code>false</code> otherwise. + */ + boolean equals(Object obj); + + /** + * Returns a hash code value for the expression. This method is supported + * for the benefit of hash tables such as those provided by + * <code>java.util.Hashtable</code>. + * + * @return a hash code value for the expression. + */ + int hashCode(); + + /** + * Returns a string representation of the expression. + * + * @return a string representation of the expression. + */ + String toString(); + + /** + * Returns <code>true</code> if a term occurs in this expression. + * + * @param term the term to be tested. + * @return <code>true</code> if a term occurs in this expression; + * <code>false</code> otherwise. + * @throws NullPointerException if <code>term == null</code>. + */ + boolean occurs(Term term); + + /** + * Substitutes all occurrences of the variables that occur in this + * expression and that are bound in the substitution by its binding term. + * + * @param sigma the substitution. + * @return a substituted copy of this expression. + * @throws NullPointerException if <code>sigma == null</code>. + */ + Exp apply(Substitution sigma); + + /** + * Standardizes all occurrences of the variables that occur in this + * expression. Remember that free variables are existentially quantified. + * + * @return a standardized copy of this expression. + */ + Exp standardize(); + + /** + * Standardizes all occurrences of the variables that occur in this + * expression. The map argument is used to store the variable already + * standardized. Remember that free variables are existentially quantified. + * + * @param images the object that maps old variable images to the standardize + * image. + * @return a standardized copy of this expression. + */ + Exp standardize(Map<String, String> images); + + /** + * Returns a typed string of this expression. + * + * @return a typed string of this expression. + */ + String toTypedString(); + + /** + * Returns a deep copy of this expression. Creates and returns a copy of + * this expression. The precise meaning of "copy" is as follow: + * + * <pre> + * x.clone() != x + * </pre> + * + * will be true, and that the expression: + * + * <pre> + * x.clone().getClass() == x.getClass() + * </pre> + * + * will be true. While it is the case that: + * + * <pre> + * x.clone().equals(x) + * </pre> + * + * will be true. Finally, note that except type of term expression are + * deeply copy. + * + * @return a deep copy of this expression. + * @see java.lang.Cloneable + */ + Exp clone(); + + /** + * Returns the prenex normal form of this expression. Note, the expression + * returned is a copy. The expression is first standardized and it is placed + * in the prenex normal form by recursively moving quantifier inward with + * the existential quantifier first using the following rewriting rules + * (which are in fact equivalences): + * <ul> + * <li><code>(and (forall (x) A) B) => (forall (x) (and A B))</code></li> + * <li><code>(or (forall (x) A) B) => (forall (x) (or A B))</code></li> + * <li><code>(and (exists (x) A) B) => (exists (x) (and A B))</code></li> + * <li><code>(or (exists (x) A) B) => (exists (x) (or A B))</code></li> + * <li> <code>(not (exists (x) (A))) => (forall (x) (not A)) </code></li> + * <li> <code>(not (forall (x) (A))) => (exists (x) (not A)) </code></li> + * <li> <code>(imply A (forall (x) (B))) => (forall (x) (imply A B)) </code></li> + * <li> <code>(imply A (exists (x) (B))) => (exists (x) (imply A B)) </code></li> + * <li> <code>(imply (forall (x) (A)) B) => (exists (x) (imply A B)) </code></li> + * <li> <code>(imply (exists (x) (A)) B) => (forall (x) (imply A B)) </code></li> + * </ul> + * + * @return the prenex normal form of this expression. + */ + Exp toPrenexNormaForm(); + + /** + * Returns a copy of this expression such that the quantifiers appear first + * and in which all existential quantifiers precede all universal + * quantifiers + * + * @return a copy of this expression such that the quantifiers appear first. + */ + Exp moveQuantifierOutward(); + + /** + * Returns the disjunctive normal form of this expression. Note, the + * expression returned is a copy. The expression is first converted into + * negative normal form and it is placed in the disjunctive normal form by + * recursively moving conjunctions inward and disjunctions outward using the + * following rewriting rules (which are in fact equivalences): + * <ul> + * <li><code>(and A (or B C)) => (or (and A B) (and A C))</code></li> + * <li><code>(and (or A B) C)) => (or (and A C) (and B C))</code></li> + * </ul> + * + * @return the disjunctive normal form of this expression. + */ + Exp toDisjunctiveNormalForm(); + + /** + * Returns the conjunctive normal form of this expression. Note, the + * expression returned is a copy. The expression is first converted into + * negative normal form and it is placed in the conjunctive normal form by + * recursively moving disjunction inward and conjunction outward using the + * following rewriting rules (which are in fact equivalences): + * <ul> + * <li><code>(or A (and B C)) => (and (or A B) (or A C))</code></li> + * <li><code>(or (and A B) C)) => (and (or A C) (or B C))</code></li> + * </ul> + * + * @return the disjunctive normal form of this expression. + */ + Exp toConjunctiveNormalForm(); + + /** + * Returns the negative normal form of this expression. Note, the expression + * returned is a copy. The negative normal form is obtained by recursively + * replace formulas appearing on the left with formulas appearing on the + * right: + * <ul> + * <li> <code>(imply A B) => (or (not A) B) </code></li> + * <li> <code>(not (not F)) => F </code></li> + * <li> <code>(not (or A B)) => (and (not A) (not B)) </code></li> + * <li> <code>(not (and A B)) => (or (not A) (not B)) </code></li> + * <li> <code>(not (imply A B)) => (and A (not B)) </code></li> + * <li> <code>(not (exists (x) (F))) => (forall (x) (not F)) </code></li> + * <li> <code>(not (forall (x) (F))) => (exists (x) (not F)) </code></li> + * <li> default a copy of the expression where inner expressions are in + * negative normal form</li> + * + * @return the negative normal form of this expression. + */ + Exp toNegativeNormalForm(); + + /** + * Returns the set of free variables of this expression. + * + * @return the set of free variables of this expression. + */ + Set<Variable> getFreeVariables(); + +} |