modules/collections/src/main/java/net/multiphasicapps/collections/UnmodifiableIterable.java

   1 // -*- Mode: Java; indent-tabs-mode: t; tab-width: 4 -*-
   2 // ---------------------------------------------------------------------------
   3 // SquirrelJME
   4 //     Copyright (C) Stephanie Gawroriski <xer@multiphasicapps.net>
   5 // ---------------------------------------------------------------------------
   6 // SquirrelJME is under the GNU General Public License v3+, or later.
   7 // See license.mkd for licensing and copyright information.
   8 // ---------------------------------------------------------------------------
   9
  10 package net.multiphasicapps.collections;
  11
  12 import cc.squirreljme.runtime.cldc.util.UnmodifiableIterator;
  13 import java.util.Iterator;
  14
  15 /**
  16  * Wraps an iterable which makes it not able to be modified.
  17  *
  18  * @param <T> The type to iterate through.
  19  * @since 2021/04/25
  20  */
  21 public final class UnmodifiableIterable<T>
  22         implements Iterable<T>
  23 {
  24         /** The iterable used. */
  25         private final Iterable<T> iterable;
  26
  27         /**
  28          * Initializes the unmodifiable iterable.
  29          *
  30          * @param __it The iterable used.
  31          * @throws NullPointerException On null arguments.
  32          * @since 2021/04/25
  33          */
  34         UnmodifiableIterable(Iterable<T> __it)
  35                 throws NullPointerException
  36         {
  37                 if (__it == null)
  38                         throw new NullPointerException("NARG");
  39
  40                 this.iterable = __it;
  41         }
  42
  43         /**
  44          * {@inheritDoc}
  45          * @since 2021/04/25
  46          */
  47         @Override
  48         public Iterator<T> iterator()
  49         {
  50                 return UnmodifiableIterator.<T>of(this.iterable);
  51         }
  52
  53         /**
  54          * Returns an unmodifiable iterable from the given one.
  55          *
  56          * @param <T> The type used.
  57          * @param __it The iterator to wrap.
  58          * @return The iterable but it cannot be modified.
  59          * @throws NullPointerException On null arguments.
  60          * @since 2021/04/25
  61          */
  62         public static <T> Iterable<T> of(Iterable<T> __it)
  63                 throws NullPointerException
  64         {
  65                 if (__it == null)
  66                         throw new NullPointerException("NARG");
  67
  68                 return new UnmodifiableIterable<>(__it);
  69         }
  70 }