nl.uu.cs.ape.sat.models.logic.constructs.Literal Maven / Gradle / Ivy
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package nl.uu.cs.ape.sat.models.logic.constructs;
import nl.uu.cs.ape.sat.automaton.State;
import nl.uu.cs.ape.sat.models.AtomMappings;
import nl.uu.cs.ape.sat.models.enums.WorkflowElement;
/**
* The {@code Literal} class represents literals (atoms that can be negated) corresponding to the usage of the modules
* and types in the solution. It is of the form {@code PredicateLabel(Attribute)} where
* {@code PredicateLabel} represents a single predicate/label used to depict {@code AbstractModule, Module}
* or {@code Type}, while {@code State} represents the state in the module/type automaton where the
* module/type is used (or not used if the literal is negative). The second attribute (referredStateArgument) is optional and used when
* the Literal represent the type that is used as tool input - referred state is the state when the type was created.
*
* {@code Literals} can start with a negation.
* {@code Literals} are compared according to the state in which they are used ({@linkplain #getUsedInStateArgument}),
* i.e. a literal that represents the n-th state in the workflow, comes before the literal that represents the (n+1)th state.
*
* @author Vedran Kasalica
*/
public class Literal implements Comparable {
/**
* Integer value used to encode the atom into cnf form.
*/
private Integer mappedAtom;
/**
* true if the atom is negated.
*/
private Boolean negated;
/**
* The {@link Atom} class represents elements of the workflow, that can be true or not (depending of the truth value of the literal).
*/
private Atom atom;
/**
* Generating an object from a mapped representation of the Literal.
*
* @param mappedLiteral Mapped literal.
* @param atomMapping Mapping of the atoms.
*/
public Literal(String mappedLiteral, AtomMappings atomMapping) {
super();
if (mappedLiteral.startsWith("-")) {
negated = true;
mappedAtom = Integer.parseInt(mappedLiteral.substring(1));
} else {
negated = false;
mappedAtom = Integer.parseInt(mappedLiteral);
}
this.atom = atomMapping.findOriginal(mappedAtom);
}
/**
* To mapped string string.
*
* @return The value of the mapped literal.
*/
public String toMappedString() {
if (negated) {
return "-" + mappedAtom;
} else {
return mappedAtom.toString();
}
}
/**
* To negated mapped string string.
*
* @return Negation of the value of the mapped literal.
*/
public String toNegatedMappedString() {
if (negated) {
return mappedAtom.toString();
} else {
return "-" + mappedAtom;
}
}
/**
* To negated mapped int int.
*
* @return Negation of the value of the mapped literal.
*/
public int toNegatedMappedInt() {
if (negated) {
return mappedAtom;
} else {
return -mappedAtom;
}
}
/**
* Return the type of the element in the workflow (tool, memory type, etc.)
*
* @return The {@link WorkflowElement} that corresponds to the Literal usage or not usage (in case of a negated literal).
*/
public WorkflowElement getWorkflowElementType() {
return atom.getWorkflowElementType();
}
/**
* Return true if the current workflow element is of the given {@link WorkflowElement} type.
*
* @param workflowElemType Element type that is current literal is compared to.
* @return true if the current workflow element corresponds to the given {@link WorkflowElement}, false otherwise.
*/
public boolean isWorkflowElementType(WorkflowElement workflowElemType) {
return atom.getWorkflowElementType() == workflowElemType;
}
/**
* Returns true in case the literal is NEGATED, false otherwise.
*
* @return true if Literal is negated.
*/
public boolean isNegated() {
return negated;
}
/**
* Returns the state in the automaton.
*
* @return String representation of the module/type automaton state.
*/
public State getUsedInStateArgument() {
return atom.getUsedInStateArgument();
}
/**
* Returns the predicate/label used to depict {@code AbstractModule, Module, Type} or {@code State}.
* Each of those refers to the element that is described by the Literal (e.g. PredicateLabel(State)).
*
* @return PredicateLabel object that is referred by the literal.
*/
public PredicateLabel getPredicate() {
return atom.getPredicate();
}
/* (non-Javadoc)
* @see java.lang.Object#hashCode()
*/
@Override
public int hashCode() {
final int prime = 31;
int result = atom.hashCode();
result = prime * result + ((negated == null) ? 0 : negated.hashCode());
return result;
}
/* (non-Javadoc)
* @see java.lang.Object#equals(java.lang.Object)
*/
@Override
public boolean equals(Object obj) {
if (this == obj)
return true;
if (obj == null)
return false;
if (getClass() != obj.getClass())
return false;
Literal other = (Literal) obj;
if (negated == null) {
if (other.negated != null)
return false;
} else if (!negated.equals(other.negated))
return false;
return atom.equals(other.atom);
}
/**
* Compare the two Literals according to the state they are used in.
* Returns a negative integer, zero, or a positive integer as this
* Literal's state comes before than, is equal to, or comes after
* than the @otherLiteral's state.
*
* @param otherLiteral The Literal to be compared
* @return The value 0 if the argument Literal's state is equal to this Literal's state;
* a value less than 0 if this Literal's state comes before the @otherLiteral's state;
* and a value greater than 0 if this Literal's state comes after the @otherLiteral's state.
*/
public int compareTo(Literal otherLiteral) {
int thisLiteralState = this.getUsedInStateArgument().getAbsoluteStateNumber();
int otherLiteralState = otherLiteral.getUsedInStateArgument().getAbsoluteStateNumber();
int diff = 0;
if ((diff = Integer.compare(thisLiteralState, otherLiteralState)) != 0) {
return diff;
} else {
return this.getPredicate().compareTo(otherLiteral.getPredicate());
}
}
/**
* Returns the Original (human readable) value of the literal. The atom of the
* Literal is transformed using the {@link Atom#toString} function.
*
* @return The value of the original literal
*/
public String toString() {
if (negated) {
return "-" + atom.toString();
} else {
return atom.toString();
}
}
}