public interface CollectionGDK enhancements for Collection.
| Type Params | Return Type | Name and description |
|---|---|---|
<T> |
public boolean |
addAll(Iterator<? extends T> items)Adds all items from the iterator to the Collection. |
<T> |
public boolean |
addAll(Iterable<? extends T> items)Adds all items from the iterable to the Collection. |
<T> |
public boolean |
addAll(T[] items)Modifies the collection by adding all the elements in the specified array to the collection. |
|
public boolean |
asBoolean()Coerce a collection instance to a boolean value. |
<T> |
public Collection<T> |
asChecked(Class<T> type)Creates a checked view of a Collection. |
<T> |
public Collection<T> |
asImmutable()A convenience method for creating an immutable Collection. |
<T> |
public Collection<T> |
asSynchronized()Creates a synchronized view of a Collection. |
<T> |
public T |
asType(Class<T> clazz)Converts the given collection to another type. |
<T> |
public Collection<T> |
asUnmodifiable()Creates an unmodifiable view of a Collection. |
|
public List |
collectNested(Closure transform)Recursively iterates through this collection transforming each non-Collection value into a new value using the closure as a transformer. |
<T> |
public Collection<T> |
each(Closure closure)Iterates through a Collection, passing each item to the given closure. |
<T> |
public Collection<T> |
eachWithIndex(Closure closure)Iterates through a Collection, passing each item and the item's index (a counter starting at zero) to the given closure. |
<T> |
public T |
find(Closure closure)Finds the first value matching the closure condition. |
<T> |
public T |
find()Finds the first item matching the IDENTITY Closure (i.e. matching Groovy truth). |
<T> |
public Collection<T> |
findAll(Closure closure)Finds all values matching the closure condition. |
<T> |
public Collection<T> |
findAll()Finds the items matching the IDENTITY Closure (i.e. matching Groovy truth). |
<T, E> |
public Collection<T> |
flatten()Flatten a Collection. |
|
public List |
getAt(String property)Support the subscript operator for Collection. |
|
public IntRange |
getIndices()Returns indices of the collection. |
<T> |
public Collection<T> |
grep(Object filter)Iterates over the collection of items and returns each item that matches the given filter - calling the Object.isCase
method used by switch statements. method can be used with different
kinds of filters like regular expressions, classes, ranges etc.
|
<T> |
public Collection<T> |
grep()Iterates over the collection returning each element that matches using the IDENTITY Closure as a filter - effectively returning all elements which satisfy Groovy truth. |
|
public String |
groovyToString()Returns Groovy's default string representation for a Collection. |
<T> |
public Collection<T> |
intersect(Collection<T> right)Create a Collection composed of the intersection of both collections. |
<T> |
public Collection<T> |
intersect(Collection<T> right, Comparator<? super T> comparator)Create a Collection composed of the intersection of both collections. |
|
public boolean |
isCase(Object switchValue)Special 'case' implementation for collections which tests if the 'switch' operand is contained in any of the 'case' values. |
|
public boolean |
isNotCase(Object switchValue)
|
<T> |
public Collection<T> |
leftShift(T value)Overloads the left shift operator to provide an easy way to append objects to a Collection. |
<T> |
public Collection<T> |
minus(Collection<?> removeMe)Create a new Collection composed of the elements of the first Collection minus every occurrence of elements of the given Collection. |
<T> |
public Collection<T> |
plus(Collection<T> right)Create a Collection as a union of two collections. |
<T> |
public Collection<T> |
plus(Iterable<T> right)Create a Collection as a union of a Collection and an Iterable. |
<T> |
public Collection<T> |
plus(T right)Create a collection as a union of a Collection and an Object. |
|
public boolean |
removeAll(Object[] items)Modifies this collection by removing its elements that are contained within the specified object array. |
<T> |
public boolean |
removeAll(Closure condition)Modifies this collection by removing the elements that are matched according to the specified closure condition. |
<E> |
public boolean |
removeElement(Object o)Modifies this collection by removing a single instance of the specified element from this collection, if it is present. |
|
public boolean |
retainAll(Object[] items)Modifies this collection so that it retains only its elements that are contained in the specified array. |
<T> |
public boolean |
retainAll(Closure condition)Modifies this collection so that it retains only its elements that are matched according to the specified closure condition. |
<T> |
public Collection<Collection<T>> |
split(Closure closure)Splits all items into two collections based on the closure condition. |
|
public String |
toListString()Returns the string representation of the given list. |
|
public String |
toListString(int maxSize)Returns the string representation of the given list. |
<T> |
public Set<T> |
toSet()Convert a Collection to a Set. |
<T> |
public Collection<T> |
union(Collection<T> right)Create a Collection composed of the union of both collections. |
<T> |
public Collection<T> |
union(Collection<T> right, Comparator<? super T> comparator)Create a Collection composed of the union of both collections. |
<T> |
public Collection<T> |
unique()Modifies this collection to remove all duplicated items, using Groovy's default number-aware comparator. |
<T> |
public Collection<T> |
unique(boolean mutate)Remove all duplicates from a given Collection using Groovy's default number-aware comparator. |
<T> |
public Collection<T> |
unique(Closure closure)A convenience method for making a collection unique using a Closure to determine duplicate (equal) items. |
<T> |
public Collection<T> |
unique(boolean mutate, Closure closure)A convenience method for making a collection unique using a Closure to determine duplicate (equal) items. |
<T> |
public Collection<T> |
unique(Comparator<? super T> comparator)Remove all duplicates from a given Collection. |
<T> |
public Collection<T> |
unique(boolean mutate, Comparator<? super T> comparator)Remove all duplicates from a given Collection. |
Adds all items from the iterator to the Collection.
items - the items to addAdds all items from the iterable to the Collection.
items - the items to addModifies the collection by adding all the elements in the specified array to the collection. The behavior of this operation is undefined if the specified array is modified while the operation is in progress.
See also plus or the '+' operator if wanting to produce a new collection
containing additional items but while leaving the original collection unchanged.
items - array containing elements to be added to this collectionCoerce a collection instance to a boolean value. A collection is coerced to false if it's empty, and to true otherwise.
assert [1,2].asBoolean() == trueassert [].asBoolean() == falseCreates a checked view of a Collection.
A convenience method for creating an immutable Collection.
Creates a synchronized view of a Collection.
Converts the given collection to another type. A default concrete type is used for List, Set, or SortedSet. If the given type has a constructor taking a collection, that is used. Otherwise, the call is deferred to Object.asType. If this collection is already of the given type, the same instance is returned.
clazz - the desired classCreates an unmodifiable view of a Collection.
Recursively iterates through this collection transforming each non-Collection value into a new value using the closure as a transformer. Returns a potentially nested list of transformed values.
assert [2,[4,6],[8],[]] == [1,[2,3],[4],[]].collectNested { it * 2 }
transform - the closure used to transform each item of the collectionIterates through a Collection, passing each item to the given closure.
closure - the closure applied on each element foundIterates through a Collection, passing each item and the item's index (a counter starting at zero) to the given closure.
closure - a Closure to operate on each itemFinds the first value matching the closure condition. Example:
def list = [1,2,3]
assert 2 == list.find { it > 1 }
closure - a closure conditionFinds the first item matching the IDENTITY Closure (i.e. matching Groovy truth).
Example:
def items = [null, 0, 0.0, false, '', [], 42, 43]
assert items.find() == 42
Finds all values matching the closure condition.
assert [2,4] == [1,2,3,4].findAll { it % 2 == 0 }closure - a closure conditionFinds the items matching the IDENTITY Closure (i.e. matching Groovy truth).
Example:
def items = [1, 2, 0, false, true, '', 'foo', [], [4, 5], null]
assert items.findAll() == [1, 2, true, 'foo', [4, 5]]
Flatten a Collection. This Collection and any nested arrays or collections have their contents (recursively) added to the new collection.
assert [1,2,3,4,5] == [1,[2,3],[[4]],[],5].flatten()Support the subscript operator for Collection.
assert [String, Long, Integer] == ["a",5L,2]["class"]
property - a StringReturns indices of the collection.
Example:
assert 0..2 == [5, 6, 7].indices
Iterates over the collection of items and returns each item that matches
the given filter - calling the Object.isCase
method used by switch statements. method can be used with different
kinds of filters like regular expressions, classes, ranges etc.
Example:
def list = ['a', 'b', 'aa', 'bc', 3, 4.5]
assert list.grep( ~/a+/ ) == ['a', 'aa']
assert list.grep( ~/../ ) == ['aa', 'bc']
assert list.grep( Number ) == [ 3, 4.5 ]
assert list.grep{ it.toString().size() == 1 } == [ 'a', 'b', 3 ]
filter - the filter to perform on each element of the collection (using the Object.isCase method)Iterates over the collection returning each element that matches using the IDENTITY Closure as a filter - effectively returning all elements which satisfy Groovy truth.
Example:
def items = [1, 2, 0, false, true, '', 'foo', [], [4, 5], null]
assert items.grep() == [1, 2, true, 'foo', [4, 5]]
Returns Groovy's default string representation for a Collection.
This is used by Groovy's formatting infrastructure (e.g., GString interpolation,
println, assert messages). By default, it delegates to
FormatHelper#toListString(Collection)#toListString(Collection).
assert [1, 2, 3].groovyToString() == '[1, 2, 3]'
If disabled, e.g. via -Dgroovy.extension.disable=groovyToString(Collection),
the normal list toString() is used instead.
Alternatively, you have the option to provide a replacement extension method in an extension module
to customize how collections are displayed throughout Groovy.
Create a Collection composed of the intersection of both collections. Any elements that exist in both collections are added to the resultant collection. For collections of custom objects; the objects should implement java.lang.Comparable
assert [4,5] == [1,2,3,4,5].intersect([4,5,6,7,8])right - a CollectionCreate a Collection composed of the intersection of both collections. Any elements that exist in both collections are added to the resultant collection. For collections of custom objects; the objects should implement java.lang.Comparable
assert [3,4] == [1,2,3,4].intersect([3,4,5,6], Comparator.naturalOrder())
assert [2,4] == [1,2,3,4].intersect([4,8,12,16,20], (x, y) -> x * x <=> y)
def one = ['a', 'B', 'c', 'd']
def two = ['b', 'C', 'd', 'e']
def compareIgnoreCase = { a, b -> a.toLowerCase() <=> b.toLowerCase() }
assert one.intersect(two) == ['d']
assert two.intersect(one) == ['d']
assert one.intersect(two, compareIgnoreCase) == ['B', 'c', 'd']
assert two.intersect(one, compareIgnoreCase) == ['b', 'C', 'd']
right - a Collectioncomparator - a ComparatorSpecial 'case' implementation for collections which tests if the 'switch' operand is contained in any of the 'case' values. For example:
switch( 3 ) {
case [1,3,5]:
assert true
break
default:
assert false
}switchValue - the switch value
Overloads the left shift operator to provide an easy way to append objects to a Collection.
def list = [1,2]
list << 3
assert list == [1,2,3]value - an Object to be added to the collection.Create a new Collection composed of the elements of the first Collection minus every occurrence of elements of the given Collection.
assert [1, "a", true, true, false, 5.3] - [true, 5.3] == [1, "a", false]removeMe - the elements to excludeCreate a Collection as a union of two collections. If the left collection is a Set, then the returned collection will be a Set otherwise a List. This operation will always create a new object for the result, while the operands remain unchanged.
assert [1,2,3,4] == [1,2] + [3,4]right - the right CollectionCreate a Collection as a union of a Collection and an Iterable. If the left collection is a Set, then the returned collection will be a Set otherwise a List. This operation will always create a new object for the result, while the operands remain unchanged.
right - the right IterableCreate a collection as a union of a Collection and an Object. If the collection is a Set, then the returned collection will be a Set otherwise a List. This operation will always create a new object for the result, while the operands remain unchanged.
assert [1,2,3] == [1,2] + 3right - an object to add/append Modifies this collection by removing its elements that are contained
within the specified object array.
See also findAll and grep when wanting to produce a new list
containing items which don't match some criteria while leaving the original collection unchanged.
items - array containing elements to be removed from this collectionModifies this collection by removing the elements that are matched according to the specified closure condition.
def list = ['a', 'b']
list.removeAll { it == 'b' }
assert list == ['a']findAll and grep when wanting to produce a new list
containing items which match some criteria but leaving the original collection unchanged.
condition - a closure conditionModifies this collection by removing a single instance of the specified element from this collection, if it is present. Essentially an alias for Collection.remove but with no ambiguity for Collection<Integer>.
Example:
def list = [1, 2, 3, 2]
list.removeElement(2)
assert [1, 3, 2] == list
o - element to be removed from this collection, if present Modifies this collection so that it retains only its elements that are contained
in the specified array. In other words, removes from this collection all of
its elements that are not contained in the specified array.
See also grep and findAll when wanting to produce a new list
containing items which match some specified items but leaving the original collection unchanged.
items - array containing elements to be retained from this collectionModifies this collection so that it retains only its elements that are matched according to the specified closure condition. In other words, removes from this collection all of its elements that don't match.
def list = ['a', 'b']
list.retainAll { it == 'b' }
assert list == ['b']findAll and grep when wanting to produce a new list
containing items which match some criteria but leaving the original collection unchanged.
condition - a closure conditionSplits all items into two collections based on the closure condition. The first list contains all items which match the closure expression. The second list all those that don't.
Example usage:
assert [[2,4],[1,3]] == [1,2,3,4].split { it % 2 == 0 }closure - a closure condition Returns the string representation of the given list. The string
displays the contents of the list, similar to a list literal, i.e.
[1, 2, a].
Returns the string representation of the given list. The string
displays the contents of the list, similar to a list literal, i.e.
[1, 2, a].
maxSize - stop after approximately this many characters and append '...'Convert a Collection to a Set. Always returns a new Set even if the Collection is already a Set.
Example usage:
def result = [1, 2, 2, 2, 3].toSet()
assert result instanceof Set
assert result == [1, 2, 3] as Set
Create a Collection composed of the union of both collections. Any elements that exist in either collections are added to the resultant collection, such that no elements are duplicated in the resultant collection. For collections of custom objects; the objects should implement java.lang.Comparable
assert [1,2,3,4,5,6,7,8] == [1,2,3,4,5].union([4,5,6,7,8])right - a CollectionCreate a Collection composed of the union of both collections. Any elements that exist in either collections are added to the resultant collection, such that no elements are duplicated in the resultant collection. For collections of custom objects; the objects should implement java.lang.Comparable
assert [1,2,3,4,5,6] == [1,2,3,4].union([3,4,5,6], Comparator.naturalOrder())
assert [4,8,12,16,20,1,3] == [4,8,12,16,20].union([1,2,3,4], (x, y) -> x * x <=> y)
def one = ['a', 'B', 'c', 'd']
def two = ['b', 'C', 'd', 'e']
def compareIgnoreCase = { a, b -> a.toLowerCase() <=> b.toLowerCase() }
assert one.union(two) == ['a', 'B', 'c', 'd', 'b', 'C', 'e']
assert two.union(one) == ['b', 'C', 'd', 'e', 'a', 'B', 'c']
assert one.union(two, compareIgnoreCase) == ['a', 'B', 'c', 'd', 'e']
assert two.union(one, compareIgnoreCase) == ['b', 'C', 'd', 'e', 'a']
right - a Collectioncomparator - a ComparatorModifies this collection to remove all duplicated items, using Groovy's default number-aware comparator.
assert [1,3] == [1,3,3].unique()Remove all duplicates from a given Collection using Groovy's default number-aware comparator. If mutate is true, it works by modifying the original object (and also returning it). If mutate is false, a new collection is returned leaving the original unchanged.
assert [1,3] == [1,3,3].unique()
def orig = [1, 3, 2, 3]
def uniq = orig.unique(false)
assert orig == [1, 3, 2, 3]
assert uniq == [1, 3, 2]
mutate - false will return a new collection containing the unique items from the collection, true will mutate collections in place and return the original collectionA convenience method for making a collection unique using a Closure to determine duplicate (equal) items.
If the closure takes a single parameter, the argument passed will be each element, and the closure should return a value used for comparison (either using Comparable.compareTo or Object.equals). If the closure takes two parameters, two items from the collection will be passed as arguments, and the closure should return an int value (with 0 indicating the items are not unique).
assert [1,4] == [1,3,4,5].unique { it % 2 }assert [2,3,4] == [2,3,3,4].unique { a, b -> a <=> b }closure - a 1 or 2 arg Closure used to determine unique itemsA convenience method for making a collection unique using a Closure to determine duplicate (equal) items. If mutate is true, it works on the receiver object and returns it. If mutate is false, a new collection is returned.
If the closure takes a single parameter, each element from the Collection will be passed to the closure. The closure should return a value used for comparison (either using Comparable.compareTo or Object.equals). If the closure takes two parameters, two items from the collection will be passed as arguments, and the closure should return an int value (with 0 indicating the items are not unique).
def orig = [1, 3, 4, 5]
def uniq = orig.unique(false) { it % 2 }
assert orig == [1, 3, 4, 5]
assert uniq == [1, 4]
def orig = [2, 3, 3, 4]
def uniq = orig.unique(false) { a, b -> a <=> b }
assert orig == [2, 3, 3, 4]
assert uniq == [2, 3, 4]
mutate - false will always cause a new list to be created, true will mutate lists in placeclosure - a 1 or 2 arg Closure used to determine unique itemsRemove all duplicates from a given Collection. Works on the original object (and also returns it). The order of members in the Collection are compared by the given Comparator. For each duplicate, the first member which is returned by the given Collection's iterator is retained, but all other ones are removed. The given Collection's original order is preserved.
class Person {
def fname, lname
String toString() {
return fname + " " + lname
}
}
class PersonComparator implements Comparator {
int compare(Object o1, Object o2) {
Person p1 = (Person) o1
Person p2 = (Person) o2
if (p1.lname != p2.lname)
return p1.lname.compareTo(p2.lname)
else
return p1.fname.compareTo(p2.fname)
}
boolean equals(Object obj) {
return this.equals(obj)
}
}
Person a = new Person(fname:"John", lname:"Taylor")
Person b = new Person(fname:"Clark", lname:"Taylor")
Person c = new Person(fname:"Tom", lname:"Cruz")
Person d = new Person(fname:"Clark", lname:"Taylor")
def list = [a, b, c, d]
List list2 = list.unique(new PersonComparator())
assert( list2 == list && list == [a, b, c] )
comparator - a ComparatorRemove all duplicates from a given Collection. If mutate is true, it works on the original object (and also returns it). If mutate is false, a new collection is returned. The order of members in the Collection are compared by the given Comparator. For each duplicate, the first member which is returned by the given Collection's iterator is retained, but all other ones are removed. The given Collection's original order is preserved.
class Person {
def fname, lname
String toString() {
return fname + " " + lname
}
}
class PersonComparator implements Comparator {
int compare(Object o1, Object o2) {
Person p1 = (Person) o1
Person p2 = (Person) o2
if (p1.lname != p2.lname)
return p1.lname.compareTo(p2.lname)
else
return p1.fname.compareTo(p2.fname)
}
boolean equals(Object obj) {
return this.equals(obj)
}
}
Person a = new Person(fname:"John", lname:"Taylor")
Person b = new Person(fname:"Clark", lname:"Taylor")
Person c = new Person(fname:"Tom", lname:"Cruz")
Person d = new Person(fname:"Clark", lname:"Taylor")
def list = [a, b, c, d]
List list2 = list.unique(false, new PersonComparator())
assert( list2 != list && list2 == [a, b, c] )
mutate - false will always cause a new collection to be created, true will mutate collections in placecomparator - a Comparator