Iterators: Difference between revisions

=={{header|Julia}}==

{{trans|C++}}

Julia has a iteration interface. Any Julia type which implements the `iterate` function is

considered an iterable. In base Julia, this includes any array type or collection, including

any subclass of AbstractRange, UnitRange, Tuple, Number, AbstractArray, BitSet, IdDict, Dict,

WeakKeyDict, EachLine, AbstractString, Set, Pair, and NamedTuple. In particular, Julia has an

extensive set of functions which act of lists and vectors. Julia's Iteration utilities can

implement the C++ example:

<lang julia>function PrintContainer(iterator)

iter = Iterators.Stateful(iterator)

foreach(x -> print(x, ", "), Iterators.take(iter, length(iter) -1))

foreach(println, Iterators.take(iter, 1))

end

function FirstFourthFifth(iterator)

iter = Iterators.Stateful(iterator)

foreach(x -> print(x, ", "), Iterators.take(iter, 1))

popfirst!(iter); popfirst!(iter)

foreach(x -> print(x, ", "), Iterators.take(iter, 1))

foreach(println, Iterators.take(iter, 1))

end

const days = ["Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"]

const colors = ["Red", "Orange", "Yellow", "Green", "Blue", "Purple"]

println("All elements:")

PrintContainer(days)

PrintContainer(colors)

println("\nFirst, fourth, and fifth elements:")

FirstFourthFifth(days)

FirstFourthFifth(colors)

println("\nReverse first, fourth, and fifth elements:")

FirstFourthFifth(Iterators.reverse(days))

FirstFourthFifth(Iterators.reverse(colors))

<lang>

<pre>

All elements:

Sunday, Monday, Tuesday, Wednesday, Thursday, Friday, Saturday

Red, Orange, Yellow, Green, Blue, Purple

First, fourth, and fifth elements:

Sunday, Wednesday, Thursday

Red, Green, Blue

Reverse first, fourth, and fifth elements:

Saturday, Wednesday, Tuesday

Purple, Yellow, Orange

</pre>