001/*
002 * Copyright (C) 2012 eXo Platform SAS.
003 *
004 * This is free software; you can redistribute it and/or modify it
005 * under the terms of the GNU Lesser General Public License as
006 * published by the Free Software Foundation; either version 2.1 of
007 * the License, or (at your option) any later version.
008 *
009 * This software is distributed in the hope that it will be useful,
010 * but WITHOUT ANY WARRANTY; without even the implied warranty of
011 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
012 * Lesser General Public License for more details.
013 *
014 * You should have received a copy of the GNU Lesser General Public
015 * License along with this software; if not, write to the Free
016 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
017 * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
018 */
019
020package org.crsh.cli.impl.parser;
021
022import org.crsh.cli.descriptor.CommandDescriptor;
023import org.crsh.cli.impl.Delimiter;
024import org.crsh.cli.impl.tokenizer.Tokenizer;
025
026import java.util.Iterator;
027import java.util.LinkedList;
028import java.util.NoSuchElementException;
029
030public final class Parser<T> implements Iterator<Event> {
031
032  /** . */
033  private final Tokenizer tokenizer;
034
035  /** . */
036  private final String mainName;
037
038  /** . */
039  private final Mode mode;
040
041  /** . */
042  private CommandDescriptor<T> command;
043
044  /** . */
045  private Status status;
046
047  /** . */
048  private final LinkedList<Event> next;
049
050  public Parser(Tokenizer tokenizer, CommandDescriptor<T> command, String mainName, Mode mode) {
051    this.tokenizer = tokenizer;
052    this.command = command;
053    this.mainName = mainName;
054    this.status = new Status.ReadingOption();
055    this.mode = mode;
056    this.next = new LinkedList<Event>();
057  }
058
059  Status getStatus() {
060    return status;
061  }
062
063  public Delimiter getDelimiter() {
064    return tokenizer.getDelimiter();
065  }
066
067  public boolean hasNext() {
068    if (next.isEmpty()) {
069      determine();
070    }
071    return next.size() > 0;
072  }
073
074  public Event next() {
075    if (!hasNext()) {
076      throw new NoSuchElementException();
077    }
078    return next.removeFirst();
079  }
080
081  public void remove() {
082    throw new UnsupportedOperationException();
083  }
084
085  private void determine() {
086    while (next.isEmpty()) {
087      Status.Response<T> nextStatus = status.process(new Status.Request<T>(mode, mainName, tokenizer, command));
088      if (nextStatus.status != null) {
089        this.status = nextStatus.status;
090      }
091      if (nextStatus.events != null) {
092        next.addAll(nextStatus.events);
093      }
094      if (nextStatus.command != null) {
095        command = (CommandDescriptor<T>)nextStatus.command;
096      }
097    }
098  }
099}