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1   /*
2   
3       dsh-commandline  Command line parser based on typed arguments.
4       Copyright (c) 2004-2012 held jointly by the individual authors.
5   
6       This library is free software; you can redistribute it and/or modify it
7       under the terms of the GNU Lesser General Public License as published
8       by the Free Software Foundation; either version 3 of the License, or (at
9       your option) any later version.
10  
11      This library is distributed in the hope that it will be useful, but WITHOUT
12      ANY WARRANTY; with out even the implied warranty of MERCHANTABILITY or
13      FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
14      License for more details.
15  
16      You should have received a copy of the GNU Lesser General Public License
17      along with this library;  if not, write to the Free Software Foundation,
18      Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307  USA.
19  
20      > http://www.fsf.org/licensing/licenses/lgpl.html
21      > http://www.opensource.org/licenses/lgpl-license.php
22  
23  */
24  package org.dishevelled.commandline;
25  
26  /**
27   * A typed argument.
28   *
29   * @param <E> argument type
30   * @author  Michael Heuer
31   * @version $Revision: 1059 $ $Date: 2012-01-03 14:03:02 -0600 (Tue, 03 Jan 2012) $
32   */
33  public interface Argument<E>
34  {
35  
36      /**
37       * Visit the specified argument string from the specified command line.
38       *
39       * <p>Previous and next argument strings in the command line may be interrogated
40       * by this argument, but the <i>cursor position</i> of the command line must
41       * be reset to what it was at the beginning of this method invocation.</p>
42       *
43       * @param s current argument string
44       * @param commandLine command line to visit
45       * @throws Exception if any error occurs
46       */
47      void visit(String s, CommandLine commandLine)
48          throws Exception;
49  
50      /**
51       * Return the short name of this argument.
52       *
53       * @return the short name of this argument
54       */
55      String getShortName();
56  
57      /**
58       * Return the long name of this argument.
59       *
60       * @return the long name of this argument
61       */
62      String getLongName();
63  
64      /**
65       * Return the description of this argument.
66       *
67       * @return the description of this argument
68       */
69      String getDescription();
70  
71      /**
72       * Return true if this argument is required.
73       *
74       * @return true if this argument is required
75       */
76      boolean isRequired();
77  
78      /**
79       * Return true if this argument was found in the
80       * command line, false if it was not found or if
81       * this argument has not visited a command line
82       * yet.
83       *
84       * @see #visit(String, CommandLine)
85       * @return true if this argument was found in the
86       *    command line
87       */
88      boolean wasFound();
89  
90      /**
91       * Return the value of this argument.
92       *
93       * @return the value of this argument
94       */
95      E getValue();
96  
97      /**
98       * Return the value of this argument or the specified default value
99       * if this argument was not found in the command line.
100      *
101      * @return the value of this argument or the specified default value
102      *    if this argument was not found in the command line
103      */
104     E getValue(E defaultValue);
105 }