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 */ 019 020 package org.crsh.cli.impl.parser; 021 022 import org.crsh.cli.descriptor.CommandDescriptor; 023 import org.crsh.cli.impl.tokenizer.Tokenizer; 024 025 import java.util.Iterator; 026 import java.util.LinkedList; 027 import java.util.NoSuchElementException; 028 029 public final class Parser<T> implements Iterator<Event> { 030 031 /** . */ 032 private final Tokenizer tokenizer; 033 034 /** . */ 035 private final Mode mode; 036 037 /** . */ 038 private CommandDescriptor<T> command; 039 040 /** . */ 041 private Status status; 042 043 /** . */ 044 private final LinkedList<Event> next; 045 046 public Parser(Tokenizer tokenizer, CommandDescriptor<T> command, Mode mode) { 047 this.tokenizer = tokenizer; 048 this.command = command; 049 this.status = new Status.ReadingOption(); 050 this.mode = mode; 051 this.next = new LinkedList<Event>(); 052 } 053 054 Status getStatus() { 055 return status; 056 } 057 058 public boolean hasNext() { 059 if (next.isEmpty()) { 060 determine(); 061 } 062 return next.size() > 0; 063 } 064 065 public Event next() { 066 if (!hasNext()) { 067 throw new NoSuchElementException(); 068 } 069 return next.removeFirst(); 070 } 071 072 public void remove() { 073 throw new UnsupportedOperationException(); 074 } 075 076 private void determine() { 077 while (next.isEmpty()) { 078 Status.Response<T> nextStatus = status.process(new Status.Request<T>(mode, tokenizer, command)); 079 if (nextStatus.status != null) { 080 this.status = nextStatus.status; 081 } 082 if (nextStatus.events != null) { 083 next.addAll(nextStatus.events); 084 } 085 if (nextStatus.command != null) { 086 command = (CommandDescriptor<T>)nextStatus.command; 087 } 088 } 089 } 090 }