/**

  * Licensed to the Apache Software Foundation (ASF) under one or more

  * contributor license agreements.  See the NOTICE file distributed with

  * this work for additional information regarding copyright ownership.

  * The ASF licenses this file to You under the Apache License, Version 2.0

  * (the "License"); you may not use this file except in compliance with

  * the License.  You may obtain a copy of the License at

  *

  *     http://www.apache.org/licenses/LICENSE-2.0

  *

  * Unless required by applicable law or agreed to in writing, software

  * distributed under the License is distributed on an "AS IS" BASIS,

  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

  * See the License for the specific language governing permissions and

  * limitations under the License.

  */

 package org.apache.commons.cli2;

 import java.util.ListIterator;

 /**

  * An Option that can process values passed on the command line in the form

  * "--file README".

  */

 public interface Argument extends Option {

     /**

      * Returns the initial separator character or

      * '\0' if no character has been set.

      *

      * @return char the initial separator character

      */

     char getInitialSeparator();

     /**

      * Processes the "README" style element of the argument.

      *

      * Values identified should be added to the CommandLine object in

      * association with this Argument.

      *

      * @see WriteableCommandLine#addValue(Option,Object)

      *

      * @param commandLine The CommandLine object to store results in.

      * @param args The arguments to process.

      * @param option The option to register value against.

      * @throws OptionException if any problems occur.

      */

     void processValues(

         final WriteableCommandLine commandLine,

         final ListIterator args,

         final Option option)

             throws OptionException;

     /**

      * Adds defaults to a CommandLine.

      *

      * @param commandLine

      *            The CommandLine object to store defaults in.

      * @param option

      *            The Option to store the defaults against.

      */

     void defaultValues(final WriteableCommandLine commandLine, final Option option);

     /**

      * Performs any necessary validation on the values added to the

      * CommandLine.

      *

      * Validation will typically involve using the

      * CommandLine.getValues(option) method to retrieve the values

      * and then either checking each value.  Optionally the String

      * value can be replaced by another Object such as a Number

      * instance or a File instance.

      *

      * @see CommandLine#getValues(Option)

      *

      * @param commandLine The CommandLine object to query.

      * @param option The option to lookup values with.

      * @throws OptionException if any problems occur.

      */

     void validate(final WriteableCommandLine commandLine, final Option option)

         throws OptionException;

     /**

      * Indicates whether argument values must be present for the CommandLine to

      * be valid.

      *

      * @see #getMinimum()

      * @see #getMaximum()

      * @return true iff the CommandLine will be invalid without at least one

      *         value

      */

     boolean isRequired();

     /**

      * Retrieves the minimum number of values required for a valid Argument

      *

      * @return the minimum number of values

      */

     int getMinimum();

     /**

      * Retrieves the maximum number of values acceptable for a valid Argument

      *

      * @return the maximum number of values

      */

     int getMaximum();

 }