| /******************************************************************************* |
| * Copyright (c) 2009 Red Hat Inc. and others. |
| * This program and the accompanying materials are made available under the |
| * terms of the Eclipse Public License v. 2.0 which is available at |
| * http://www.eclipse.org/legal/epl-2.0. |
| * |
| * SPDX-License-Identifier: EPL-2.0 |
| * |
| * Contributors: |
| * Alexander Kurtakov - initial API and implementation |
| *******************************************************************************/ |
| package org.eclipse.dltk.sh.internal.ui.text; |
| |
| import org.eclipse.jface.text.rules.ICharacterScanner; |
| import org.eclipse.jface.text.rules.IRule; |
| import org.eclipse.jface.text.rules.IToken; |
| import org.eclipse.jface.text.rules.IWordDetector; |
| import org.eclipse.jface.text.rules.Token; |
| |
| /** |
| * This rule captures parameter expansions that are not covered by |
| * DollarBraceCountingRule. That is, all dollar-prefixed variables including |
| * special variables where encapsulation in braces is not necessary. |
| */ |
| public class DollarRule implements IRule { |
| |
| private final StringBuffer buffer = new StringBuffer(); |
| private final IToken defaultToken; |
| private final IWordDetector detector; |
| private final IToken successToken; |
| |
| public DollarRule(IWordDetector detector, IToken defaultToken, IToken token) { |
| this.detector = detector; |
| this.successToken = token; |
| this.defaultToken = defaultToken; |
| } |
| |
| /** |
| * Returns whether the specified character is a special parameter in shell |
| * script. A dollar sign combined with any of the following characters will |
| * be highlighted, but no characters after that. |
| * <p> |
| * '*', '@' - positional parameters starting from 1<br> |
| * '#' - number of positional parameters<br> |
| * '?' - exit status of the last executed foreground command<br> |
| * '-' - current option flags<br> |
| * '$' - PID of the shell<br> |
| * '!' - PID of the last executed background command<br> |
| * '_' - pathname used to invoke the shell and every subsequent command <br> |
| * '0' - usually the name of the file used to invoke the shell<br> |
| * '1' to '9' - expands to the corresponding positional parameters, |
| * parameters 10+ must be referenced with braces like ${12} |
| * |
| * @param c |
| * a character to test |
| * @return true if the specified character is a special parameter |
| */ |
| private static boolean isSpecial(char c) { |
| return ((c == '*') || (c == '@') || (c == '#') || (c == '?') || (c == '-') || (c == '$') || (c == '!') |
| || (c == '_') || Character.isDigit(c)); |
| } |
| |
| @Override |
| public IToken evaluate(ICharacterScanner scanner) { |
| int c = scanner.read(); |
| if (detector.isWordStart((char) c)) { |
| buffer.setLength(0); |
| do { |
| buffer.append((char) c); |
| c = scanner.read(); |
| if ((buffer.length() == 1) && isSpecial((char) c)) { |
| return successToken; |
| } |
| } while ((c != ICharacterScanner.EOF) && detector.isWordPart((char) c)); |
| scanner.unread(); |
| if (buffer.length() > 1) { |
| return successToken; |
| } |
| if (defaultToken.isUndefined()) { |
| unreadBuffer(scanner); |
| } |
| return defaultToken; |
| } |
| scanner.unread(); |
| return Token.UNDEFINED; |
| } |
| |
| /** |
| * Returns the characters in the buffer to the scanner. |
| * |
| * @param scanner |
| * the scanner to be used |
| */ |
| protected void unreadBuffer(ICharacterScanner scanner) { |
| for (int i = buffer.length() - 1; i >= 0; i--) { |
| scanner.unread(); |
| } |
| } |
| } |