package adql.query.operand.function;
/*
* This file is part of ADQLLibrary.
*
* ADQLLibrary is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* ADQLLibrary is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with ADQLLibrary. If not, see <http://www.gnu.org/licenses/>.
*
* Copyright 2012-2015 - UDS/Centre de Données astronomiques de Strasbourg (CDS),
* Astronomisches Rechen Institute (ARI)
*/
import java.util.Iterator;
import java.util.NoSuchElementException;
import adql.query.ADQLIterator;
import adql.query.ADQLObject;
import adql.query.TextPosition;
import adql.query.operand.ADQLOperand;
/**
* Represents any kind of function.
*
* @author Grégory Mantelet (CDS;ARI)
* @version 1.4 (06/2015)
*/
public abstract class ADQLFunction implements ADQLOperand {
/** Position of this {@link ADQLFunction} in the ADQL query string.
* @since 1.4 */
private TextPosition position = null;
@Override
public final TextPosition getPosition(){
return position;
}
/**
* Set the position of this {@link ADQLFunction} in the ADQL query string.
*
* @param position New position of this {@link ADQLFunction}
* @since 1.4
*/
public final void setPosition(final TextPosition position){
this.position = position;
}
/**
* Gets the number of parameters this function has.
*
* @return Number of parameters.
*/
public abstract int getNbParameters();
/**
* Gets the list of all parameters of this function.
*
* @return Its parameters list.
*/
public abstract ADQLOperand[] getParameters();
/**
* Gets the index-th parameter.
*
* @param index Parameter number.
* @return The corresponding parameter.
*
* @throws ArrayIndexOutOfBoundsException If the index is incorrect (index < 0 || index >= getNbParameters()).
*/
public abstract ADQLOperand getParameter(int index) throws ArrayIndexOutOfBoundsException;
/**
* Replaces the index-th parameter by the given one.
*
* @param index Index of the parameter to replace.
* @param replacer The replacer.
*
* @return The replaced parameter.
*
* @throws ArrayIndexOutOfBoundsException If the index is incorrect (index < 0 || index >= getNbParameters()).
* @throws NullPointerException If a required parameter must be replaced by a NULL object.
* @throws Exception If another error occurs.
*/
public abstract ADQLOperand setParameter(int index, ADQLOperand replacer) throws ArrayIndexOutOfBoundsException, NullPointerException, Exception;
/**
* Creates an iterator on the parameters of this function.
*
* @return Parameters iterator.
*/
public Iterator<ADQLOperand> paramIterator(){
return new ParameterIterator(this);
}
@Override
public ADQLIterator adqlIterator(){
return new ADQLIterator(){
private int index = -1;
@Override
public ADQLObject next(){
try{
return getParameter(++index);
}catch(ArrayIndexOutOfBoundsException ex){
throw new NoSuchElementException();
}
}
@Override
public boolean hasNext(){
return index + 1 < getNbParameters();
}
@Override
public void replace(ADQLObject replacer) throws UnsupportedOperationException, IllegalStateException{
if (index <= -1)
throw new IllegalStateException("replace(ADQLObject) impossible: next() has not yet been called !");
if (replacer == null)
remove();
else if (replacer instanceof ADQLOperand){
try{
setParameter(index, (ADQLOperand)replacer);
}catch(Exception e){
e.printStackTrace();
throw new UnsupportedOperationException(e);
}
}else
throw new UnsupportedOperationException("Impossible to replace the " + index + "-th parameter of \"" + toADQL() + "\" by an object whose the class (" + replacer.getClass().getName() + ") is not ADQLOperand !");
}
@Override
public void remove(){
if (index <= -1)
throw new IllegalStateException("remove() impossible: next() has not yet been called !");
else
throw new UnsupportedOperationException("Impossible to remove a parameter of an ADQL function (here the " + index + "-th parameter of \"" + toADQL() + "\")");
}
};
}
@Override
public String toADQL(){
String adql = getName() + "(";
for(int i = 0; i < getNbParameters(); i++)
adql += ((i == 0) ? "" : ", ") + getParameter(i).toADQL();
return adql + ")";
}
/**
* Lets iterating on all parameters of the given function.
*
* @author Grégory Mantelet (CDS)
* @version 01/2012
*/
protected class ParameterIterator implements Iterator<ADQLOperand> {
protected final ADQLFunction function;
protected int index = -1;
public ParameterIterator(ADQLFunction fct) throws NullPointerException{
if (fct == null)
throw new NullPointerException("Impossible to build an iterator on a function without the function on which the iterator must be applied !");
else
function = fct;
}
@Override
public boolean hasNext(){
return (index + 1) < function.getNbParameters();
}
@Override
public ADQLOperand next(){
index++;
return function.getParameter(index);
}
@Override
public void remove() throws UnsupportedOperationException{
try{
function.setParameter(index, null);
}catch(Exception e){
throw new UnsupportedOperationException(e);
}
}
}
}