java.lang
Class Iterable

collectEntries

public Map collectEntries(Closure transform)

 

A variant of collectEntries for Iterables.

Parameters:

transform - the closure used for transforming, which has an item from self as the parameter and should return a Map.Entry, a Map or a two-element list containing the resulting key and value.

Returns:

a Map of the transformed entries

Since:

1.8.7

See:

Iterator#collectEntries(Closure).

collectEntries

public Map collectEntries()

 

A variant of collectEntries for Iterables using the identity closure as the transform.

Returns:

a Map of the transformed entries

Since:

1.8.7

See:

Iterator#collectEntries().

collectEntries

public Map collectEntries(Map collector, Closure transform)

 

A variant of collectEntries for Iterables using a supplied map as the destination of transformed entries.

Parameters:

collector - the Map into which the transformed entries are put.

transform - the closure used for transforming, which has an item from self as the parameter and should return a Map.Entry, a Map or a two-element list containing the resulting key and value.

Returns:

the collector with all transformed values added to it

Since:

1.8.7

See:

Iterator#collectEntries(Map, Closure).

collectEntries

public Map collectEntries(Map collector)

 

A variant of collectEntries for Iterables using the identity closure as the transform and a supplied map as the destination of transformed entries.

Parameters:

collector - the Map into which the transformed entries are put.

Returns:

the collector with all transformed values added to it

Since:

1.8.7

See:

Iterator#collectEntries(Map).

drop

public List drop(int num)

 

Drops the given number of elements from the head of this Iterable.

class AbcIterable implements Iterable {
    Iterator iterator() { "abc".iterator() }
}
def abc = new AbcIterable()
assert abc.drop(0) == ['a', 'b', 'c']
assert abc.drop(1) == ['b', 'c']
assert abc.drop(3) == []
assert abc.drop(5) == []

Parameters:

num - the number of elements to drop from this Iterable.

Returns:

a List consisting of all the elements of this Iterable minus the first num elements, or an empty list if it has less then num elements.

Since:

1.8.7

dropWhile

public List dropWhile(Closure condition)

 

Returns a suffix of this Iterable where elements are dropped from the front while the given closure evaluates to true.

class AbcIterable implements Iterable {
    Iterator iterator() { "abc".iterator() }
}
def abc = new AbcIterable()
assert abc.dropWhile{ it < 'b' } == ['b', 'c']
assert abc.dropWhile{ it <= 'b' } == ['c']

Parameters:

condition - the closure that must evaluate to true to continue dropping elements.

Returns:

the shortest suffix of the given Iterable such that the given closure condition evaluates to true for each element dropped from the front of the Iterable

Since:

1.8.7

first

public Object first()

 

Returns the first item from the Iterable.

def set = [3, 4, 2] as LinkedHashSet
assert set.first() == 3
// check original is unaltered
assert set == [3, 4, 2] as Set

The first element returned by the Iterable's iterator is returned. If the Iterable doesn't guarantee a defined order it may appear like a random element is returned.

Returns:

the first item from the Iterable

Since:

1.8.7

getAt

public Object getAt(int idx)

 

Support the subscript operator for an Iterable. Typical usage:

// custom Iterable example:
class MyIterable implements Iterable {
  Iterator iterator() { [1, 2, 3].iterator() }
}
def myIterable = new MyIterable()
assert myIterable[1] == 2

// Set example:
def set = [1,2,3] as LinkedHashSet
assert set[1] == 2

Parameters:

idx - an index value (-self.size() <= idx < self.size()) but using -ve index values will be inefficient.

Returns:

the value at the given index (after normalisation) or null if no corresponding value was found

Since:

2.1.0

last

public Object last()

 

Returns the last item from the Iterable.

def set = [3, 4, 2] as LinkedHashSet
assert set.last() == 2
// check original unaltered
assert set == [3, 4, 2] as Set

The first element returned by the Iterable's iterator is returned. If the Iterable doesn't guarantee a defined order it may appear like a random element is returned.

Returns:

the first item from the Iterable

Since:

1.8.7

take

public List take(int num)

 

Returns the first num elements from the head of this Iterable.

class AbcIterable implements Iterable {
    Iterator iterator() { "abc".iterator() }
}
def abc = new AbcIterable()
assert abc.take(0) == []
assert abc.take(1) == ['a']
assert abc.take(3) == ['a', 'b', 'c']
assert abc.take(5) == ['a', 'b', 'c']

Parameters:

num - the number of elements to take from this Iterable.

Returns:

a List consisting of the first num elements from this Iterable, or else all the elements from the Iterable if it has less then num elements.

Since:

1.8.7

takeWhile

public List takeWhile(Closure condition)

 

Returns a List containing the longest prefix of the elements from this Iterable where each element passed to the given closure evaluates to true.

class AbcIterable implements Iterable {
    Iterator iterator() { "abc".iterator() }
}
def abc = new AbcIterable()
assert abc.takeWhile{ it < 'b' } == ['a']
assert abc.takeWhile{ it <= 'b' } == ['a', 'b']

Parameters:

condition - the closure that must evaluate to true to continue taking elements.

Returns:

a List containing a prefix of the elements from the given Iterable where each element passed to the given closure evaluates to true

Since:

1.8.7

toList

public List toList()

 

Convert an Iterable to a List. The Iterable's iterator will become exhausted of elements after making this conversion.

Returns:

a List

Since:

1.8.7