1 files changed, 94 insertions, 0 deletions
diff --git a/plugins/org.eclipse.dltk.sh.ui/src/org/eclipse/dltk/sh/ui/text/DollarRule.java b/plugins/org.eclipse.dltk.sh.ui/src/org/eclipse/dltk/sh/ui/text/DollarRule.java
new file mode 100644
index 0000000..0ee86e1
--- /dev/null
+++ b/plugins/org.eclipse.dltk.sh.ui/src/org/eclipse/dltk/sh/ui/text/DollarRule.java
@@ -0,0 +1,94 @@
+/*******************************************************************************
+ * Copyright (c) 2009 Red Hat Inc. and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *     Alexander Kurtakov - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.dltk.sh.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();
+	}
+}