TclVariableRule.java

/*******************************************************************************
 * Copyright (c) 2005, 2017 IBM Corporation 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
 *
 *******************************************************************************/
package org.eclipse.dltk.tcl.internal.ui.rules;

import org.eclipse.dltk.tcl.internal.parser.raw.CodeScanner;
import org.eclipse.dltk.tcl.internal.parser.raw.SimpleTclParser;
import org.eclipse.dltk.tcl.internal.parser.raw.TclParseException;
import org.eclipse.dltk.tcl.internal.parser.raw.VariableSubstitution;
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.Token;

public class TclVariableRule implements IRule {
	private IToken token;

	public TclVariableRule(IToken token) {
		super();
		this.token = token;
	}

	private class SkipCodeScanner extends CodeScanner {

		ICharacterScanner scanner;

		public SkipCodeScanner(ICharacterScanner scanner) {
			super(null);
			this.scanner = scanner;
		}

		@Override
		public int read() {
			return scanner.read();
		}

		@Override
		public boolean isEOF() {
			int res = scanner.read();
			if (res == -1)
				return true;
			scanner.unread();
			return false;
		}

		@Override
		public void unread() {
			scanner.unread();
		}

		@Override
		public int getPosition() {
			return scanner.getColumn();
		}

	}

	@Override
	public IToken evaluate(ICharacterScanner scanner) {
		SkipCodeScanner scs = new SkipCodeScanner(scanner);
		if (!VariableSubstitution.iAm(scs)) {
			return Token.UNDEFINED;
		}

		VariableSubstitution vs = new VariableSubstitution();
		try {
			vs.readMe(scs, new SimpleTclParser());
		} catch (TclParseException e) {
			// e.printStackTrace();
			return Token.UNDEFINED;
		}

		return token;
	}

}