/*
* eXist Open Source Native XML Database
* Copyright (C) 2001-06 Wolfgang M. Meier
* wolfgang@exist-db.org
* http://exist.sourceforge.net
*
* This program 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 2
* of the License, or (at your option) any later version.
*
* This program 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 this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
* $Id$
*/
package org.exist.xquery;
import org.exist.xquery.value.Item;
import org.exist.xquery.value.Sequence;
import org.exist.xquery.util.ExpressionDumper;
/**
* Abstract base class for simple functions. Subclasses should overwrite
* method {@link #eval(Sequence[], Sequence)}.
*
* @author Wolfgang Meier (wolfgang@exist-db.org)
*/
public abstract class BasicFunction extends Function {
public BasicFunction(XQueryContext context, FunctionSignature signature) {
super(context, signature);
}
/* (non-Javadoc)
* @see org.exist.xquery.Expression#eval(org.exist.xquery.value.Sequence, org.exist.xquery.value.Item)
*/
public Sequence eval(Sequence contextSequence, Item contextItem) throws XPathException {
if (context.getProfiler().isEnabled()) {
context.getProfiler().start(this);
context.getProfiler().message(this, Profiler.DEPENDENCIES, "DEPENDENCIES", Dependency.getDependenciesName(this.getDependencies()));
if (contextSequence != null)
{context.getProfiler().message(this, Profiler.START_SEQUENCES, "CONTEXT SEQUENCE", contextSequence);}
if (contextItem != null)
{context.getProfiler().message(this, Profiler.START_SEQUENCES, "CONTEXT ITEM", contextItem.toSequence());}
}
if (contextItem != null)
{contextSequence = contextItem.toSequence();}
final int argCount = getArgumentCount();
final Sequence[] args = new Sequence[argCount];
for (int i = 0; i < argCount; i++) {
try {
args[i] = getArgument(i).eval(contextSequence, contextItem);
} catch (final XPathException e) {
e.prependMessage(
ErrorCodes.XPTY0004,
"checking function parameter " + (i + 1) + " in call " + ExpressionDumper.dump(this) + ": ");
throw e;
}
}
final Sequence result = eval(args, contextSequence);
if (context.getProfiler().isEnabled())
{context.getProfiler().end(this, "", result);}
return result;
}
/**
* Process the function. All arguments are passed in the array args. The number of
* arguments, their type and cardinality have already been checked to match
* the function signature.
*
* @param args
* @param contextSequence
*/
public abstract Sequence eval(Sequence[] args, Sequence contextSequence) throws XPathException;
}