/* Alloy Analyzer 4 -- Copyright (c) 2006-2009, Felix Chang
*
* Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files
* (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify,
* merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
* OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
* LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF
* OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
package edu.mit.csail.sdg.alloy4viz;
import java.util.Collection;
import java.util.ArrayList;
import java.util.List;
import edu.mit.csail.sdg.alloy4.ConstList;
import edu.mit.csail.sdg.alloy4.Util;
import edu.mit.csail.sdg.alloy4.ConstList.TempList;
/** Immutable; represents an Alloy tuple.
*
* <p><b>Thread Safety:</b> Can be called only by the AWT event thread.
*/
public final class AlloyTuple implements Comparable<AlloyTuple> {
/** The unmodifiable list of atoms in this tuple. */
private final ConstList<AlloyAtom> atoms;
/** Creates a new AlloyTuple containing the atoms specified by the list; atoms.size() must be 2 or above. */
public AlloyTuple(List<AlloyAtom> atoms) {
if (atoms==null || atoms.size()<2)
throw new RuntimeException("An AlloyTuple object must have 2 or more atoms.");
this.atoms = ConstList.make(atoms);
}
/** Creates a new AlloyTuple containing the atoms specified by the list; atoms.size() must be 2 or above. */
public AlloyTuple(AlloyAtom... atoms) {
if (atoms==null || atoms.length<2)
throw new RuntimeException("An AlloyTuple object must have 2 or more atoms.");
this.atoms = Util.asList(atoms);
}
/** Project this tuple and return an unmodifiable list of remaining atoms (after removing zero or more columns)
* @param columns - the collection of columns to remove (0 is the first column, 1 is the second column...)
*/
public ConstList<AlloyAtom> project(Collection<Integer> columns) {
TempList<AlloyAtom> list = new TempList<AlloyAtom>(atoms.size());
for(int i=0; i<atoms.size(); i++) if (!columns.contains(i)) list.add(atoms.get(i));
if (list.size()==atoms.size()) return atoms; else return list.makeConst();
}
/** Returns the arity of this AlloyTuple. */
public int getArity() { return atoms.size(); }
/** Returns an unmodifiable list of the AlloyAtoms in this AlloyTuple. */
public List<AlloyAtom> getAtoms() { return atoms; }
/** Returns the first AlloyAtom in this AlloyTuple. */
public AlloyAtom getStart() { return atoms.get(0); }
/** Returns the last AlloyAtom in this AlloyTuple. */
public AlloyAtom getEnd() { return atoms.get(atoms.size()-1); }
/** Returns a new AlloyTuple whose list of atoms is the same but in reverse. */
public AlloyTuple reverse() {
List<AlloyAtom> newlist = new ArrayList<AlloyAtom>(atoms.size());
for(int i=atoms.size()-1; i>=0; i--) newlist.add(atoms.get(i));
return new AlloyTuple(newlist);
}
/** Provides a human-readable description of this AlloyTuple. */
@Override public String toString() {
String s="<";
for(int i=0; i<atoms.size(); i++) { if (i!=0) s=s+", "; s=s+atoms.get(i); }
return s+">";
}
/** Two tuples are first compared based on length; if the length is the same, we compare atom-by-atom.
* <br> We guarantee x.equals(y) iff x.compareTo(y)==0
*/
public int compareTo(AlloyTuple that) {
if (that==null) return 1;
if (atoms.size() < that.atoms.size()) return -1;
if (atoms.size() > that.atoms.size()) return 1;
for(int i=0; i<atoms.size(); i++) {
int result=atoms.get(i).compareTo(that.atoms.get(i));
if (result!=0) return result;
}
return 0;
}
/** Two tuples are equal if they have the same atoms in the same order. */
@Override public boolean equals(Object other) {
if (!(other instanceof AlloyTuple)) return false;
if (other==this) return true;
return atoms.equals(((AlloyTuple)other).atoms);
}
/** Compute a hash code based on the list of atoms. */
@Override public int hashCode() { return atoms.hashCode(); }
}