Package org.djutils.immutablecollections

Class ImmutableCollections

java.lang.Object

org.djutils.immutablecollections.ImmutableCollections

public final class ImmutableCollections
extends Object

Static methods operating on immutable collections, or a mix of an immutable collection and a mutable collection.

Copyright (c) 2013-2021 Delft University of Technology, PO Box 5, 2600 AA, Delft, the Netherlands. All rights reserved.
BSD-style license. See DJUTILS License.

Version:

$Revision$, $LastChangedDate$, by $Author$, initial version Feb 26, 2019

Author:

Alexander Verbraeck, Peter Knoppers

Method Summary

Modifier and Type	Method	Description
static <T> int	binarySearch(ImmutableList<? extends Comparable<? super T>> il, T key)	Search the immutable list for the specified object using the binary search algorithm.
static <T> int	binarySearch(ImmutableList<? extends T> il, T key, Comparator<? super T> comparator)	Search the immutable list for the specified object using the binary search algorithm.
static boolean	disjoint(Collection<?> c1, ImmutableCollection<?> ic2)	Determine if an immutable collection and a (non immutable) collection have no common members.
static boolean	disjoint(ImmutableCollection<?> ic1, Collection<?> c2)	Determine if an immutable collection and a (non immutable) collection have no common members.
static boolean	disjoint(ImmutableCollection<?> ic1, ImmutableCollection<?> ic2)	Determine if two immutable collections have no common members.
static <T> ImmutableList<T>	emptyImmutableList()	Return an immutable empty list.
static <T,V> ImmutableMap<T,V>	emptyImmutableMap()	Return an immutable empty map.
static <T> ImmutableSet<T>	emptyImmutableSet()	Return an immutable empty set.
static int	frequency(ImmutableCollection<?> ic, Object o)	Return the number of occurrences of an object in an immutable collection.
static int	indexOfSubList(List<?> source, ImmutableList<?> target)	Returns the starting position of the first occurrence of the specified target list within the specified source list, or -1 if there is no such occurrence.
static int	indexOfSubList(ImmutableList<?> source, List<?> target)	Returns the starting position of the first occurrence of the specified target list within the specified source list, or -1 if there is no such occurrence.
static int	indexOfSubList(ImmutableList<?> source, ImmutableList<?> target)	Returns the starting position of the first occurrence of the specified target list within the specified source list, or -1 if there is no such occurrence.
static int	lastIndexOfSubList(List<?> source, ImmutableList<?> target)	Returns the starting position of the last occurrence of the specified target list within the specified source list, or -1 if there is no such occurrence.
static int	lastIndexOfSubList(ImmutableList<?> source, List<?> target)	Returns the starting position of the last occurrence of the specified target list within the specified source list, or -1 if there is no such occurrence.
static int	lastIndexOfSubList(ImmutableList<?> source, ImmutableList<?> target)	Returns the starting position of the last occurrence of the specified target list within the specified source list, or -1 if there is no such occurrence.
static <T extends Object & Comparable<? super T>> T	max(ImmutableCollection<? extends T> ic)	Returns the maximum element of an immutable collection according to the natural ordering of its elements.
static <T> T	max(ImmutableCollection<? extends T> ic, Comparator<? super T> comparator)	Returns the maximum element of an immutable collection according to the natural ordering of its elements.
static <T extends Object & Comparable<? super T>> T	min(ImmutableCollection<? extends T> ic)	Returns the minimum element of an immutable collection according to the natural ordering of its elements.
static <T> T	min(ImmutableCollection<? extends T> ic, Comparator<? super T> comparator)	Returns the minimum element of an immutable collection according to the natural ordering of its elements.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

emptyImmutableSet

public static <T> ImmutableSet<T> emptyImmutableSet()

Return an immutable empty set.

Type Parameters:

T - the data type of the ImmutableSet

Returns:

ImmutableSet<T>; an immutable empty set

emptyImmutableMap

public static <T,V> ImmutableMap<T,V> emptyImmutableMap()

Return an immutable empty map.

Type Parameters:

T - the key type of the ImmutableMap

V - the value type of the ImmutableMap

Returns:

ImmutableMap<T, V>; an immutable empty map

emptyImmutableList

public static <T> ImmutableList<T> emptyImmutableList()

Return an immutable empty list.

Type Parameters:

T - the data type of the ImmutableList

Returns:

ImmutableList<T>; an immutable empty list

binarySearch

public static <T> int binarySearch(ImmutableList<? extends Comparable<? super T>> il,
                                   T key)

Search the immutable list for the specified object using the binary search algorithm. The list must be ordered according to the natural ordering of its elements.

Type Parameters:

T - the data type of the ImmutableList

Parameters:

il - ImmutableList<? extends Comparable<? super T>>; the list (must be ordered according to the natural ordering of <code>T</code>

key - T; the element to search for.

Returns:

int; if key is present in the list, the index of key, or, when key is not present in the list (-(insertion point) - 1) where insertion point is the index of key if it were contained in the list.

binarySearch

public static <T> int binarySearch(ImmutableList<? extends T> il,
                                   T key,
                                   Comparator<? super T> comparator)

Search the immutable list for the specified object using the binary search algorithm. The list must be ordered according to the comparator.

Type Parameters:

T - the object type in the list

Parameters:

il - ImmutableList<? extends T>; the list (must be ordered according to the <code>comparator</code>

key - T; the element to search for.

comparator - Comparator<? super T>; a comparator for T

Returns:

int; if key is present in the list, the index of key, or, when key is not present in the list (-(insertion point) - 1) where insertion point is the index of key if it were contained in the list.

disjoint

public static boolean disjoint(ImmutableCollection<?> ic1,
                               ImmutableCollection<?> ic2)

Determine if two immutable collections have no common members.

Parameters:

ic1 - ImmutableCollection<?>; ImmutableCollection<?> one immutable collection

ic2 - ImmutableCollection<?>; ImmutableCollection<?> another immutable collection

Returns:

boolean; true if the collections have no common members; false if the collections have at least one member in common

disjoint

public static boolean disjoint(ImmutableCollection<?> ic1,
                               Collection<?> c2)

Determine if an immutable collection and a (non immutable) collection have no common members.

Parameters:

ic1 - ImmutableCollection<?>; ImmutableCollection<?> an immutable collection

c2 - Collection<?>; Collection<?> a (mutable) collection

Returns:

boolean; true if the collections have no common members; false if the collections have at least one member in common

disjoint

public static boolean disjoint(Collection<?> c1,
                               ImmutableCollection<?> ic2)

Determine if an immutable collection and a (non immutable) collection have no common members.

Parameters:

c1 - Collection<?>; Collection<?> a (mutable) collection

ic2 - ImmutableCollection<?>; ImmutableCollection<?> an immutable collection

Returns:

boolean; true if the collections have no common members; false if the collections have at least one member in common

indexOfSubList

public static int indexOfSubList(ImmutableList<?> source,
                                 ImmutableList<?> target)

Returns the starting position of the first occurrence of the specified target list within the specified source list, or -1 if there is no such occurrence.

Parameters:

source - ImmutableList<?>; the list in which to find the first occurrence of target

target - ImmutableList<?>; the pattern to find in source

Returns:

int; the index in source of the first occurrence of target or -1 if target does not occur anywhere in source

indexOfSubList

public static int indexOfSubList(ImmutableList<?> source,
                                 List<?> target)

Returns the starting position of the first occurrence of the specified target list within the specified source list, or -1 if there is no such occurrence.

Parameters:

source - ImmutableList<?>; the list in which to find the first occurrence of target

target - List<?>; the pattern to find in source

Returns:

int; the index in source of the first occurrence of target or -1 if target does not occur anywhere in source

indexOfSubList

public static int indexOfSubList(List<?> source,
                                 ImmutableList<?> target)

Returns the starting position of the first occurrence of the specified target list within the specified source list, or -1 if there is no such occurrence.

Parameters:

source - List<?>; the list in which to find the first occurrence of target

target - ImmutableList<?>; the pattern to find in source

Returns:

int; the index in source of the first occurrence of target or -1 if target does not occur anywhere in source

lastIndexOfSubList

public static int lastIndexOfSubList(ImmutableList<?> source,
                                     ImmutableList<?> target)

Returns the starting position of the last occurrence of the specified target list within the specified source list, or -1 if there is no such occurrence.

Parameters:

source - ImmutableList<?>; the list in which to find the last occurrence of target

target - ImmutableList<?>; the pattern to find in source

Returns:

int; the index in source of the last occurrence of target or -1 if target does not occur anywhere in source

lastIndexOfSubList

public static int lastIndexOfSubList(ImmutableList<?> source,
                                     List<?> target)

Returns the starting position of the last occurrence of the specified target list within the specified source list, or -1 if there is no such occurrence.

Parameters:

source - ImmutableList<?>; the list in which to find the last occurrence of target

target - List<?>; the pattern to find in source

Returns:

int; the index in source of the last occurrence of target or -1 if target does not occur anywhere in source

lastIndexOfSubList

public static int lastIndexOfSubList(List<?> source,
                                     ImmutableList<?> target)

Returns the starting position of the last occurrence of the specified target list within the specified source list, or -1 if there is no such occurrence.

Parameters:

source - List<?>; the list in which to find the last occurrence of target

target - ImmutableList<?>; the pattern to find in source

Returns:

int; the index in source of the last occurrence of target or -1 if target does not occur anywhere in source

max

public static <T extends Object & Comparable<? super T>> T max(ImmutableCollection<? extends T> ic)

Returns the maximum element of an immutable collection according to the natural ordering of its elements.

Type Parameters:

T - the object type in the collection

Parameters:

ic - ImmutableCollection<T extends Object & Comparable<? super T>>; the immutable collection

Returns:

T <T extends Object & Comparable<? super T>>; the maximum element in the immutable collection

Throws:

NoSuchElementException - if the immutable collection is empty.

max

public static <T> T max(ImmutableCollection<? extends T> ic,
                        Comparator<? super T> comparator)

Returns the maximum element of an immutable collection according to the natural ordering of its elements.

Type Parameters:

T - the object type in the collection

Parameters:

ic - ImmutableCollection<T extends Object & Comparable<? super T>>; the immutable collection

comparator - Comparator<? super T>; a comparator for T

Returns:

T <T extends Object & Comparable<? super T>>; the maximum element in the immutable collection

Throws:

NoSuchElementException - if the immutable collection is empty.

min

public static <T extends Object & Comparable<? super T>> T min(ImmutableCollection<? extends T> ic)

Returns the minimum element of an immutable collection according to the natural ordering of its elements.

Type Parameters:

T - the object type in the collection

Parameters:

ic - ImmutableCollection<T extends Object & Comparable<? super T>>; the immutable collection

Returns:

T <T extends Object & Comparable<? super T>>; the minimum element in the immutable collection

Throws:

NoSuchElementException - if the immutable collection is empty.

min

public static <T> T min(ImmutableCollection<? extends T> ic,
                        Comparator<? super T> comparator)

Returns the minimum element of an immutable collection according to the natural ordering of its elements.

Type Parameters:

T - the object type in the collection

Parameters:

ic - ImmutableCollection<T extends Object & Comparable<? super T>>; the immutable collection

comparator - Comparator<? super T>; a comparator for T

Returns:

T <T extends Object & Comparable<? super T>>; the minimum element in the immutable collection

Throws:

NoSuchElementException - if the immutable collection is empty.

frequency

public static int frequency(ImmutableCollection<?> ic,
                            Object o)

Return the number of occurrences of an object in an immutable collection.

Parameters:

ic - ImmutableCollection<?>; the immutable collection

o - Object; the object to count the number occurrences of

Returns:

int; the number of occurrences of o in ic