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/* Generic definitions */
/* Assertions (useful to generate conditional code) */
/* Current type and class (and size, if applicable) */
/* Value methods */
/* Interfaces (keys) */
/* Interfaces (values) */
/* Abstract implementations (keys) */
/* Abstract implementations (values) */
/* Static containers (keys) */
/* Static containers (values) */
/* Implementations */
/* Synchronized wrappers */
/* Unmodifiable wrappers */
/* Other wrappers */
/* Methods (keys) */
/* Methods (values) */
/* Methods (keys/values) */
/* Methods that have special names depending on keys (but the special names depend on values) */
/* Equality */
/* Object/Reference-only definitions (keys) */
/* Primitive-type-only definitions (keys) */
/* Object/Reference-only definitions (values) */
/*		 
 * Copyright (C) 2002-2013 Sebastiano Vigna 
 *
 * Licensed 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 it.unimi.dsi.fastutil.floats;
import java.util.Iterator;
import java.util.ListIterator;
import java.util.NoSuchElementException;
/** A class providing static methods and objects that do useful things with type-specific iterators.
 *
 * @see Iterator
 */
public class FloatIterators {
 private FloatIterators() {}
 /** A class returning no elements and a type-specific iterator interface.
	 *
	 * 

This class may be useful to implement your own in case you subclass * a type-specific iterator. */ public static class EmptyIterator extends AbstractFloatListIterator implements java.io.Serializable, Cloneable { private static final long serialVersionUID = -7046029254386353129L; protected EmptyIterator() {} public boolean hasNext() { return false; } public boolean hasPrevious() { return false; } public float nextFloat() { throw new NoSuchElementException(); } public float previousFloat() { throw new NoSuchElementException(); } public int nextIndex() { return 0; } public int previousIndex() { return -1; } public int skip( int n ) { return 0; }; public int back( int n ) { return 0; }; public Object clone() { return EMPTY_ITERATOR; } private Object readResolve() { return EMPTY_ITERATOR; } } /** An empty iterator (immutable). It is serializable and cloneable. * *

The class of this objects represent an abstract empty iterator * that can iterate as a type-specific (list) iterator. */ @SuppressWarnings("rawtypes") public final static EmptyIterator EMPTY_ITERATOR = new EmptyIterator(); /** An iterator returning a single element. */ private static class SingletonIterator extends AbstractFloatListIterator { private final float element; private int curr; public SingletonIterator( final float element ) { this.element = element; } public boolean hasNext() { return curr == 0; } public boolean hasPrevious() { return curr == 1; } public float nextFloat() { if ( ! hasNext() ) throw new NoSuchElementException(); curr = 1; return element; } public float previousFloat() { if ( ! hasPrevious() ) throw new NoSuchElementException(); curr = 0; return element; } public int nextIndex() { return curr; } public int previousIndex() { return curr - 1; } } /** Returns an iterator that iterates just over the given element. * * @param element the only element to be returned by a type-specific list iterator. * @return an iterator that iterates just over element. */ public static FloatListIterator singleton( final float element ) { return new SingletonIterator ( element ); } /** A class to wrap arrays in iterators. */ private static class ArrayIterator extends AbstractFloatListIterator { private final float[] array; private final int offset, length; private int curr; public ArrayIterator( final float[] array, final int offset, final int length ) { this.array = array; this.offset = offset; this.length = length; } public boolean hasNext() { return curr < length; } public boolean hasPrevious() { return curr > 0; } public float nextFloat() { if ( ! hasNext() ) throw new NoSuchElementException(); return array[ offset + curr++ ]; } public float previousFloat() { if ( ! hasPrevious() ) throw new NoSuchElementException(); return array[ offset + --curr ]; } public int skip( int n ) { if ( n <= length - curr ) { curr += n; return n; } n = length - curr; curr = length; return n; } public int back( int n ) { if ( n <= curr ) { curr -= n; return n; } n = curr; curr = 0; return n; } public int nextIndex() { return curr; } public int previousIndex() { return curr - 1; } } /** Wraps the given part of an array into a type-specific list iterator. * *

The type-specific list iterator returned by this method will iterate * length times, returning consecutive elements of the given * array starting from the one with index offset. * * @param array an array to wrap into a type-specific list iterator. * @param offset the first element of the array to be returned. * @param length the number of elements to return. */ public static FloatListIterator wrap( final float[] array, final int offset, final int length ) { FloatArrays.ensureOffsetLength( array, offset, length ); return new ArrayIterator ( array, offset, length ); } /** Wraps the given array into a type-specific list iterator. * *

The type-specific list iterator returned by this method will return * all elements of the given array. * * @param array an array to wrap into a type-specific list iterator. */ public static FloatListIterator wrap( final float[] array ) { return new ArrayIterator ( array, 0, array.length ); } /** Unwraps an iterator into an array starting at a given offset for a given number of elements. * *

This method iterates over the given type-specific iterator and stores the elements * returned, up to a maximum of length, in the given array starting at offset. * The number of actually unwrapped elements is returned (it may be less than max if * the iterator emits less than max elements). * * @param i a type-specific iterator. * @param array an array to contain the output of the iterator. * @param offset the first element of the array to be returned. * @param max the maximum number of elements to unwrap. * @return the number of elements unwrapped. */ public static int unwrap( final FloatIterator i, final float array[], int offset, final int max ) { if ( max < 0 ) throw new IllegalArgumentException( "The maximum number of elements (" + max + ") is negative" ); if ( offset < 0 || offset + max > array.length ) throw new IllegalArgumentException(); int j = max; while( j-- != 0 && i.hasNext() ) array[ offset++ ] = i.nextFloat(); return max - j - 1; } /** Unwraps an iterator into an array. * *

This method iterates over the given type-specific iterator and stores the * elements returned in the given array. The iteration will stop when the * iterator has no more elements or when the end of the array has been reached. * * @param i a type-specific iterator. * @param array an array to contain the output of the iterator. * @return the number of elements unwrapped. */ public static int unwrap( final FloatIterator i, final float array[] ) { return unwrap( i, array, 0, array.length ); } /** Unwraps an iterator, returning an array, with a limit on the number of elements. * *

This method iterates over the given type-specific iterator and returns an array * containing the elements returned by the iterator. At most max elements * will be returned. * * @param i a type-specific iterator. * @param max the maximum number of elements to be unwrapped. * @return an array containing the elements returned by the iterator (at most max). */ @SuppressWarnings("unchecked") public static float[] unwrap( final FloatIterator i, int max ) { if ( max < 0 ) throw new IllegalArgumentException( "The maximum number of elements (" + max + ") is negative" ); float array[] = new float[ 16 ]; int j = 0; while( max-- != 0 && i.hasNext() ) { if ( j == array.length ) array = FloatArrays.grow( array, j + 1 ); array[ j++ ] = i.nextFloat(); } return FloatArrays.trim( array, j ); } /** Unwraps an iterator, returning an array. * *

This method iterates over the given type-specific iterator and returns an array * containing the elements returned by the iterator. * * @param i a type-specific iterator. * @return an array containing the elements returned by the iterator. */ public static float[] unwrap( final FloatIterator i ) { return unwrap( i, Integer.MAX_VALUE ); } /** Unwraps an iterator into a type-specific collection, with a limit on the number of elements. * *

This method iterates over the given type-specific iterator and stores the elements * returned, up to a maximum of max, in the given type-specific collection. * The number of actually unwrapped elements is returned (it may be less than max if * the iterator emits less than max elements). * * @param i a type-specific iterator. * @param c a type-specific collection array to contain the output of the iterator. * @param max the maximum number of elements to unwrap. * @return the number of elements unwrapped. Note that * this is the number of elements returned by the iterator, which is not necessarily the number * of elements that have been added to the collection (because of duplicates). */ public static int unwrap( final FloatIterator i, final FloatCollection c, final int max ) { if ( max < 0 ) throw new IllegalArgumentException( "The maximum number of elements (" + max + ") is negative" ); int j = max; while( j-- != 0 && i.hasNext() ) c.add( i.nextFloat() ); return max - j - 1; } /** Unwraps an iterator into a type-specific collection. * *

This method iterates over the given type-specific iterator and stores the * elements returned in the given type-specific collection. The returned count on the number * unwrapped elements is a long, so that it will work also with very large collections. * * @param i a type-specific iterator. * @param c a type-specific collection to contain the output of the iterator. * @return the number of elements unwrapped. Note that * this is the number of elements returned by the iterator, which is not necessarily the number * of elements that have been added to the collection (because of duplicates). */ public static long unwrap( final FloatIterator i, final FloatCollection c ) { long n = 0; while( i.hasNext() ) { c.add( i.nextFloat() ); n++; } return n; } /** Pours an iterator into a type-specific collection, with a limit on the number of elements. * *

This method iterates over the given type-specific iterator and adds * the returned elements to the given collection (up to max). * * @param i a type-specific iterator. * @param s a type-specific collection. * @param max the maximum number of elements to be poured. * @return the number of elements poured. Note that * this is the number of elements returned by the iterator, which is not necessarily the number * of elements that have been added to the collection (because of duplicates). */ public static int pour( final FloatIterator i, final FloatCollection s, final int max ) { if ( max < 0 ) throw new IllegalArgumentException( "The maximum number of elements (" + max + ") is negative" ); int j = max; while( j-- != 0 && i.hasNext() ) s.add( i.nextFloat() ); return max - j - 1; } /** Pours an iterator into a type-specific collection. * *

This method iterates over the given type-specific iterator and adds * the returned elements to the given collection. * * @param i a type-specific iterator. * @param s a type-specific collection. * @return the number of elements poured. Note that * this is the number of elements returned by the iterator, which is not necessarily the number * of elements that have been added to the collection (because of duplicates). */ public static int pour( final FloatIterator i, final FloatCollection s ) { return pour( i, s, Integer.MAX_VALUE ); } /** Pours an iterator, returning a type-specific list, with a limit on the number of elements. * *

This method iterates over the given type-specific iterator and returns * a type-specific list containing the returned elements (up to max). Iteration * on the returned list is guaranteed to produce the elements in the same order * in which they appeared in the iterator. * * * @param i a type-specific iterator. * @param max the maximum number of elements to be poured. * @return a type-specific list containing the returned elements, up to max. */ public static FloatList pour( final FloatIterator i, int max ) { final FloatArrayList l = new FloatArrayList (); pour( i, l, max ); l.trim(); return l; } /** Pours an iterator, returning a type-specific list. * *

This method iterates over the given type-specific iterator and returns * a list containing the returned elements. Iteration * on the returned list is guaranteed to produce the elements in the same order * in which they appeared in the iterator. * * @param i a type-specific iterator. * @return a type-specific list containing the returned elements. */ public static FloatList pour( final FloatIterator i ) { return pour( i, Integer.MAX_VALUE ); } private static class IteratorWrapper extends AbstractFloatIterator { final Iterator i; public IteratorWrapper( final Iterator i ) { this.i = i; } public boolean hasNext() { return i.hasNext(); } public void remove() { i.remove(); } public float nextFloat() { return ((i.next()).floatValue()); } } /** Wraps a standard iterator into a type-specific iterator. * *

This method wraps a standard iterator into a type-specific one which will handle the * type conversions for you. Of course, any attempt to wrap an iterator returning the * instances of the wrong class will generate a {@link ClassCastException}. The * returned iterator is backed by i: changes to one of the iterators * will affect the other, too. * *

If i is already type-specific, it will returned and no new object * will be generated. * * @param i an iterator. * @return a type-specific iterator backed by i. */ @SuppressWarnings({ "rawtypes", "unchecked" }) public static FloatIterator asFloatIterator( final Iterator i ) { if ( i instanceof FloatIterator ) return (FloatIterator )i; return new IteratorWrapper ( i ); } private static class ListIteratorWrapper extends AbstractFloatListIterator { final ListIterator i; public ListIteratorWrapper( final ListIterator i ) { this.i = i; } public boolean hasNext() { return i.hasNext(); } public boolean hasPrevious() { return i.hasPrevious(); } public int nextIndex() { return i.nextIndex(); } public int previousIndex() { return i.previousIndex(); } @SuppressWarnings("unchecked") public void set( float k ) { i.set( (Float.valueOf(k)) ); } @SuppressWarnings("unchecked") public void add( float k ) { i.add( (Float.valueOf(k)) ); } public void remove() { i.remove(); } public float nextFloat() { return ((i.next()).floatValue()); } public float previousFloat() { return ((i.previous()).floatValue()); } } /** Wraps a standard list iterator into a type-specific list iterator. * *

This method wraps a standard list iterator into a type-specific one * which will handle the type conversions for you. Of course, any attempt * to wrap an iterator returning the instances of the wrong class will * generate a {@link ClassCastException}. The * returned iterator is backed by i: changes to one of the iterators * will affect the other, too. * *

If i is already type-specific, it will returned and no new object * will be generated. * * @param i a list iterator. * @return a type-specific list iterator backed by i. */ @SuppressWarnings({ "rawtypes", "unchecked" }) public static FloatListIterator asFloatIterator( final ListIterator i ) { if ( i instanceof FloatListIterator ) return (FloatListIterator )i; return new ListIteratorWrapper ( i ); } private static class IteratorConcatenator extends AbstractFloatIterator { final FloatIterator a[]; int offset, length, lastOffset = -1; public IteratorConcatenator( final FloatIterator a[], int offset, int length ) { this.a = a; this.offset = offset; this.length = length; advance(); } private void advance() { while( length != 0 ) { if ( a[ offset ].hasNext() ) break; length--; offset++; } return; } public boolean hasNext() { return length > 0; } public float nextFloat() { if ( ! hasNext() ) throw new NoSuchElementException(); float next = a[ lastOffset = offset ].nextFloat(); advance(); return next; } public void remove() { if ( lastOffset == -1 ) throw new IllegalStateException(); a[ lastOffset ].remove(); } public int skip( int n ) { lastOffset = -1; int skipped = 0; while( skipped < n && length != 0 ) { skipped += a[ offset ].skip( n - skipped ); if ( a[ offset ].hasNext() ) break; length--; offset++; } return skipped; } } /** Concatenates all iterators contained in an array. * *

This method returns an iterator that will enumerate in order the elements returned * by all iterators contained in the given array. * * @param a an array of iterators. * @return an iterator obtained by concatenation. */ public static FloatIterator concat( final FloatIterator a[] ) { return concat( a, 0, a.length ); } /** Concatenates a sequence of iterators contained in an array. * *

This method returns an iterator that will enumerate in order the elements returned * by a[ offset ], then those returned * by a[ offset + 1 ], and so on up to * a[ offset + length - 1 ]. * * @param a an array of iterators. * @param offset the index of the first iterator to concatenate. * @param length the number of iterators to concatenate. * @return an iterator obtained by concatenation of length elements of a starting at offset. */ public static FloatIterator concat( final FloatIterator a[], final int offset, final int length ) { return new IteratorConcatenator ( a, offset, length ); } /** An unmodifiable wrapper class for iterators. */ public static class UnmodifiableIterator extends AbstractFloatIterator { final protected FloatIterator i; @SuppressWarnings("unchecked") public UnmodifiableIterator( final FloatIterator i ) { this.i = i; } public boolean hasNext() { return i.hasNext(); } public float nextFloat() { return i.nextFloat(); } public Float next() { return i.next(); } } /** Returns an unmodifiable iterator backed by the specified iterator. * * @param i the iterator to be wrapped in an unmodifiable iterator. * @return an unmodifiable view of the specified iterator. */ public static FloatIterator unmodifiable( final FloatIterator i ) { return new UnmodifiableIterator ( i ); } /** An unmodifiable wrapper class for bidirectional iterators. */ public static class UnmodifiableBidirectionalIterator extends AbstractFloatBidirectionalIterator { final protected FloatBidirectionalIterator i; @SuppressWarnings("unchecked") public UnmodifiableBidirectionalIterator( final FloatBidirectionalIterator i ) { this.i = i; } public boolean hasNext() { return i.hasNext(); } public boolean hasPrevious() { return i.hasPrevious(); } public float nextFloat() { return i.nextFloat(); } public float previousFloat() { return i.previousFloat(); } public Float next() { return i.next(); } public Float previous() { return i.previous(); } } /** Returns an unmodifiable bidirectional iterator backed by the specified bidirectional iterator. * * @param i the bidirectional iterator to be wrapped in an unmodifiable bidirectional iterator. * @return an unmodifiable view of the specified bidirectional iterator. */ public static FloatBidirectionalIterator unmodifiable( final FloatBidirectionalIterator i ) { return new UnmodifiableBidirectionalIterator ( i ); } /** An unmodifiable wrapper class for list iterators. */ public static class UnmodifiableListIterator extends AbstractFloatListIterator { final protected FloatListIterator i; @SuppressWarnings("unchecked") public UnmodifiableListIterator( final FloatListIterator i ) { this.i = i; } public boolean hasNext() { return i.hasNext(); } public boolean hasPrevious() { return i.hasPrevious(); } public float nextFloat() { return i.nextFloat(); } public float previousFloat() { return i.previousFloat(); } public int nextIndex() { return i.nextIndex(); } public int previousIndex() { return i.previousIndex(); } public Float next() { return i.next(); } public Float previous() { return i.previous(); } } /** Returns an unmodifiable list iterator backed by the specified list iterator. * * @param i the list iterator to be wrapped in an unmodifiable list iterator. * @return an unmodifiable view of the specified list iterator. */ public static FloatListIterator unmodifiable( final FloatListIterator i ) { return new UnmodifiableListIterator ( i ); } /** A wrapper promoting the results of a ByteIterator. */ protected static class ByteIteratorWrapper implements FloatIterator { final it.unimi.dsi.fastutil.bytes.ByteIterator iterator; public ByteIteratorWrapper( final it.unimi.dsi.fastutil.bytes.ByteIterator iterator ) { this.iterator = iterator; } public boolean hasNext() { return iterator.hasNext(); } public Float next() { return Float.valueOf( iterator.nextByte() ); } public float nextFloat() { return iterator.nextByte(); } public void remove() { iterator.remove(); } public int skip( final int n ) { return iterator.skip( n ); } } /** Returns an iterator backed by the specified byte iterator. * @return an iterator backed by the specified byte iterator. */ public static FloatIterator wrap( final it.unimi.dsi.fastutil.bytes.ByteIterator iterator ) { return new ByteIteratorWrapper( iterator ); } /** A wrapper promoting the results of a ShortIterator. */ protected static class ShortIteratorWrapper implements FloatIterator { final it.unimi.dsi.fastutil.shorts.ShortIterator iterator; public ShortIteratorWrapper( final it.unimi.dsi.fastutil.shorts.ShortIterator iterator ) { this.iterator = iterator; } public boolean hasNext() { return iterator.hasNext(); } public Float next() { return Float.valueOf( iterator.nextShort() ); } public float nextFloat() { return iterator.nextShort(); } public void remove() { iterator.remove(); } public int skip( final int n ) { return iterator.skip( n ); } } /** Returns an iterator backed by the specified short iterator. * @return an iterator backed by the specified short iterator. */ public static FloatIterator wrap( final it.unimi.dsi.fastutil.shorts.ShortIterator iterator ) { return new ShortIteratorWrapper( iterator ); } }





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