| /******************************************************************************* |
| * Copyright (c) 2009, 2017 Cloudsmith Inc. and others. |
| * |
| * This program and the accompanying materials |
| * are made available under the terms of the Eclipse Public License 2.0 |
| * which accompanies this distribution, and is available at |
| * https://www.eclipse.org/legal/epl-2.0/ |
| * |
| * SPDX-License-Identifier: EPL-2.0 |
| * |
| * Contributors: |
| * Cloudsmith Inc. - initial API and implementation |
| *******************************************************************************/ |
| package org.eclipse.equinox.internal.p2.metadata.expression; |
| |
| import java.util.Iterator; |
| import org.eclipse.equinox.p2.metadata.expression.IEvaluationContext; |
| import org.eclipse.equinox.p2.query.IMatchQuery; |
| import org.eclipse.equinox.p2.query.IQuery; |
| |
| public final class WrappedIQuery extends Function { |
| |
| /** |
| * <p>The WrappedIQuery constructor takes an array with one or two arguments. |
| * The first argument must evaluate to an instance of {@link IQuery}. The second |
| * argument is optional. The following applies:</p><ul> |
| * <li>If first argument evaluates to an instance of {@link IMatchQuery}, then |
| * a provided second argument assumed to be the candidate to match. The |
| * variable <code>this</code> will be used if no second argument is not provided.</li> |
| * <li>For all other types of queries the second argument must evaluate |
| * to an iterator. If it is not provided, it defaults to the variable |
| * <code>everything</code>. |
| * </ul> |
| * @param operands |
| */ |
| public WrappedIQuery(Expression[] operands) { |
| super(assertLength(operands, 1, 2, KEYWORD_IQUERY)); |
| } |
| |
| @Override |
| @SuppressWarnings("unchecked") |
| public Object evaluate(IEvaluationContext context) { |
| Object query = operands[0].evaluate(context); |
| |
| if (query instanceof IMatchQuery<?>) { |
| Object value = null; |
| if (operands.length > 1) |
| value = operands[1].evaluate(context); |
| else |
| value = ExpressionFactory.THIS.evaluate(context); |
| return Boolean.valueOf(((IMatchQuery<Object>) query).isMatch(value)); |
| } |
| |
| if (!(query instanceof IQuery<?>)) |
| throw new IllegalArgumentException("iquery first argument must be an IQuery instance"); //$NON-NLS-1$ |
| |
| Iterator<?> iterator = null; |
| if (operands.length > 1) |
| iterator = operands[1].evaluateAsIterator(context); |
| else |
| iterator = ExpressionFactory.EVERYTHING.evaluateAsIterator(context); |
| |
| return ((IQuery<Object>) query).perform((Iterator<Object>) iterator); |
| } |
| |
| @Override |
| public String getOperator() { |
| return KEYWORD_IQUERY; |
| } |
| |
| @Override |
| public boolean isReferenceTo(Variable variable) { |
| Object firstOp = operands[0]; |
| if (firstOp instanceof Literal) { |
| Object query = ((Literal) firstOp).value; |
| return (query instanceof IMatchQuery<?>) ? variable == ExpressionFactory.THIS : variable == ExpressionFactory.EVERYTHING; |
| } |
| return false; |
| } |
| |
| @Override |
| int countAccessToEverything() { |
| return isReferenceTo(ExpressionFactory.EVERYTHING) ? 1 : 0; |
| } |
| } |