Example usage for java.lang Iterable Iterable

Introduction

In this page you can find the example usage for java.lang Iterable Iterable.

Prototype

Iterable

Source Link

Usage

From source file:Main.java

@SuppressWarnings("unchecked")
public static <T> Iterable<T> concat(final Iterable<T>... collections) {
    return new Iterable<T>() {
        @Override/*from www .  j av a 2 s.  com*/
        public Iterator<T> iterator() {
            return new Iterator<T>() {
                final Iterable<T>[] iterables = collections;
                int iteratorIdx = 0;
                Iterator<T> it = collections[0].iterator();

                private synchronized void advanceCursor() {
                    while (!it.hasNext() && iteratorIdx < iterables.length) {
                        iteratorIdx += 1;
                        if (iteratorIdx == iterables.length) {
                            it = new Iterator<T>() {
                                @Override
                                public boolean hasNext() {
                                    return false;
                                }

                                @Override
                                public T next() {
                                    throw new NoSuchElementException();
                                }

                                @Override
                                public void remove() {
                                    throw new RuntimeException();
                                }
                            };
                        } else {
                            it = iterables[iteratorIdx].iterator();
                        }
                    }
                }

                @Override
                public synchronized boolean hasNext() {
                    advanceCursor();
                    return iteratorIdx != iterables.length && it.hasNext();
                }

                @Override
                public synchronized T next() {
                    advanceCursor();
                    if (iteratorIdx == iterables.length)
                        throw new NoSuchElementException();
                    return it.next();
                }

                @Override
                public void remove() {
                    throw new UnsupportedOperationException();
                }
            };
        }
    };
}

From source file:Main.java

/**
 * Convience method for wrapping an iterator into an iterable.
 * This is used mainly for using of a foreach loop with an iterator
 * /*from ww w.  j ava  2  s  .  c  o m*/
 * @param it
 * @return
 */
public static <T> Iterable<T> getIterable(final Iterator<T> it) {
    return new Iterable<T>() {
        public Iterator<T> iterator() {
            return it;
        }
    };
}

From source file:Permutator.java

public static <T> Iterable<List<T>> permutations(final List<T> list) {
    return new Iterable<List<T>>() {
        public Iterator<List<T>> iterator() {
            return new Iterator<List<T>>() {
                private int current = 0;
                private final long length = factorial(list.size());

                public List<T> next() {
                    if (!hasNext()) {
                        throw new NoSuchElementException();
                    }//  w ww. ja v  a 2s .  co m
                    List<T> permutation = new ArrayList<T>(list);
                    int k = current;
                    for (int j = 2; j <= list.size(); j++) {
                        k /= j - 1;
                        Collections.swap(permutation, (k % j), j - 1);
                    }
                    current++;
                    return permutation;
                }

                public void remove() {
                    throw new UnsupportedOperationException();
                }

                public boolean hasNext() {
                    return current < length;
                }
            };
        }
    };
}

From source file:Main.java

public static Iterable<Node> iterate(final NodeList nodeList) {
    return new Iterable<Node>() {
        @Override/*  w w w.  ja  v a2  s.c  o m*/
        public Iterator<Node> iterator() {

            return new Iterator<Node>() {

                int index = 0;

                @Override
                public void remove() {
                    throw new UnsupportedOperationException();
                }

                @Override
                public Node next() {
                    return nodeList.item(index++);
                }

                @Override
                public boolean hasNext() {
                    return index < nodeList.getLength();
                }
            };
        }
    };
}

From source file:Main.java

public static Iterable<String> iterate(Matcher matcher) {
    return new Iterable<String>() {
        @Override/*from www . ja  v a2 s  .  c  o m*/
        public Iterator<String> iterator() {
            return new Iterator<String>() {
                @Override
                public boolean hasNext() {
                    return matcher.find();
                }

                @Override
                public String next() {
                    return matcher.group();
                }
            };
        }

        @Override
        public void forEach(Consumer<? super String> action) {
            while (matcher.find()) {
                action.accept(matcher.group());
            }
        }
    };
}

From source file:Main.java

/**
 * Generate an instance of Iterable for an array.
 * This may be used in a foreach loop.//w ww .j  ava2s .co m
 * 
 * @param array
 * @return
 */
public static <T> Iterable<T> getIterable(final T[] array) {
    return new Iterable<T>() {
        public Iterator<T> iterator() {
            return getIterator(array);
        }
    };
}

From source file:Main.java

public static <T> Iterable<T> reverse(final List<T> list) {
    return new Iterable<T>() {
        public Iterator<T> iterator() {
            final ListIterator<T> listIterator = list.listIterator(list.size());

            return new Iterator<T>() {
                public boolean hasNext() {
                    return listIterator.hasPrevious();
                }/*from w  w w.  j  ava2 s . c o  m*/

                public T next() {
                    return listIterator.previous();
                }

                public void remove() {
                    listIterator.remove();
                }
            };
        }
    };
}

From source file:Main.java

public static <T> Iterable<T> iterable(final Enumeration<T> enumeration) {
    return new Iterable<T>() {
        @Override//from w  w  w .j a v a 2  s.  com
        public Iterator<T> iterator() {
            return org.springframework.util.CollectionUtils.toIterator(enumeration);
        }
    };
}

From source file:Main.java

/**
 * Gets the reverse iterable of an Iterable (i.e. a collection).
 * If this collection implements ListIterator, then this operation is far more efficent.
 * Otherwise, the iterable is iterated through, where the results are stored, before
 * returning a iterable that iterates through the resulting list.
 * //from w  w  w.  j ava2 s.c  o m
 * @param it
 * @return
 */
public static <T> Iterable<T> getReverse(Iterable<T> it) {
    if (it instanceof List) { //list takes up less computation and memory - use built in list iterator
        final ListIterator<T> iter = ((List<T>) it).listIterator(((List<T>) it).size());
        return new Iterable<T>() {
            public Iterator<T> iterator() {
                return getReverseIterator(iter);
            }
        };
    }

    int size = 10;
    if (it instanceof Collection) { //if not a list, but is a collection
        size = ((Collection<T>) it).size();
    }
    List<T> list = new Vector<>(size);
    for (T t : it) {
        list.add(t);
    }
    final ListIterator<T> iter = list.listIterator(list.size());

    return new Iterable<T>() {
        public Iterator<T> iterator() {
            return getReverseIterator(iter);
        }
    };
}

From source file:Main.java

public static <T> Iterable<T> concat(final List<Iterable<? extends T>> iterables) {
    return new Iterable<T>() {
        public Iterator<T> iterator() {
            return new Iterator<T>() {
                Iterator<? extends T> iter;
                int pos = 0;

                public boolean hasNext() {
                    while (pos < iterables.size()) {
                        if (iter == null)
                            iter = iterables.get(pos).iterator();
                        if (iter.hasNext())
                            return true;
                        iter = null;//from   w w  w .j  a v  a  2  s  . com
                        pos++;
                    }
                    return false;
                }

                public T next() {
                    while (pos < iterables.size()) {
                        if (iter == null)
                            iter = iterables.get(pos).iterator();
                        if (iter.hasNext())
                            return iter.next();
                        iter = null;
                        pos++;
                    }
                    throw new NoSuchElementException();
                }

                public void remove() {
                    throw new UnsupportedOperationException("remove");
                }
            };
        }
    };
}