Ranges - rust-course

Range expressions allows to define integer ranges that can used:

See Match, Slices and for for practical usages of ranges. For the moment, we just present in Table 1 the syntax to use when defining a range.

A Range being also an Iterator, we may use Iterator methods on it like rev(). See Table 2 for some interesting iterator methods.

Table 1:Range syntax

Range expression	Meaning
`1..5`	From 1 included to 5 excluded.
`1..=5`	From 1 to 5, both included.
`..5` ^[1]	From start of object to 5 excluded.
`..=5` ^[1]	From start of object to 5 included.
`3..` ^[1]	From 3 included to end of object.
`..` ^[2]	All indices of the whole object.

Table 2:Some methods of the Iterator trait

Method	Description
`all(f)`	Test if all elements satisfy the predicate `f()`.
`any(f)`	Test if any element satisfies the predicate `f()`.
`chain(other)`	Construct a new `Iterator` made of the two iterators in sequence.
`collect()`	Transform the iterator into a collection.
`count()`	Consume the iterator and return the number of iterations.
`cycle()`	Repeat endlessly.
`enumerate()`	Create a new `Iterator` of pairs `(index, element)`.
`filter(f)`	Create a new `Iterator` that filters elements according to the closure `f()`.
`for_each(f)`	Call the closure `f()` on each element.
`map(f)`	Create a new `Iterator` that applies a closure `f` onto each element.
`max()`	Return the max element.
`min()`	Return the min element.
`product()`	Multiply all elements.
`reduce(f)`	Reduce the elements using the reducing operator `f()`.
`rev()`	Reverse the iterator.
`skip(n)`	Skip the `n` first elements.
`step_by(n)`	Step by the given amount.
`sum()`	Sum the elements.
`take(n)`	Yield only the `n` first elements.
`unzip()`	Convert an iterator of pairs into a pair of containers.
`zip(other)`	Zip two iterators into an iterator of pairs.

Footnotes¶

4.4 Ranges