FunctionCall.java

/*
 * Copyright Aduna (http://www.aduna-software.com/) (c) 2007.
 *
 * Licensed under the Aduna BSD-style license.
 */
package org.openrdf.query.algebra;

import java.util.ArrayList;
import java.util.List;

/**
 * A call to an (external) function that operates on zero or more arguments.
 * 
 * @author Arjohn Kampman
 */
public class FunctionCall extends QueryModelNodeBase implements ValueExpr {

	/*-----------*
	 * Variables *
	 *-----------*/

	protected String uri;

	/**
	 * The operator's argument.
	 */
	protected List<ValueExpr> args = new ArrayList<ValueExpr>();

	/*--------------*
	 * Constructors *
	 *--------------*/

	public FunctionCall() {
	}

	/**
	 * Creates a new unary value operator.
	 * 
	 * @param arg
	 *        The operator's argument, must not be <tt>null</tt>.
	 */
	public FunctionCall(String uri, ValueExpr... args) {
		setURI(uri);
		addArgs(args);
	}

	public FunctionCall(String uri, Iterable<ValueExpr> args) {
		setURI(uri);
		addArgs(args);
	}

	/*---------*
	 * Methods *
	 *---------*/

	public String getURI() {
		return uri;
	}

	public void setURI(String uri) {
		this.uri = uri;
	}

	public List<ValueExpr> getArgs() {
		return args;
	}

	public void setArgs(Iterable<ValueExpr> args) {
		this.args.clear();
		addArgs(args);
	}

	public void addArgs(ValueExpr... args) {
		for (ValueExpr arg : args) {
			addArg(arg);
		}
	}

	public void addArgs(Iterable<ValueExpr> args) {
		for (ValueExpr arg : args) {
			addArg(arg);
		}
	}

	public void addArg(ValueExpr arg) {
		assert arg != null : "arg must not be null";
		args.add(arg);
		arg.setParentNode(this);
	}

	public <X extends Exception> void visit(QueryModelVisitor<X> visitor)
		throws X
	{
		visitor.meet(this);
	}

	@Override
	public <X extends Exception> void visitChildren(QueryModelVisitor<X> visitor)
		throws X
	{
		for (ValueExpr arg : args) {
			arg.visit(visitor);
		}

		super.visitChildren(visitor);
	}

	@Override
	public void replaceChildNode(QueryModelNode current, QueryModelNode replacement)
	{
		int index = args.indexOf(current);
		if (index >= 0) {
			args.set(index, (ValueExpr)replacement);
			replacement.setParentNode(this);
		}
		else {
			super.replaceChildNode(current, replacement);
		}
	}

	@Override
	public FunctionCall clone() {
		FunctionCall clone = (FunctionCall)super.clone();

		List<ValueExpr> argsClone = new ArrayList<ValueExpr>(getArgs().size());
		for (ValueExpr arg : getArgs()) {
			argsClone.add(arg.clone());
		}

		clone.setArgs(argsClone);

		return clone;
	}
}