Struct joinery::JoinIter

pub struct JoinIter<Iter: Iterator, Sep> { /* fields omitted */ }

An iterator for a Join.

Emits the elements of the Join's underlying iterator, interspersed with its separator. Note that it uses clone to generate copies of the separator while iterating, but also keep in mind that in most cases the JoinItem instance will have a trivially cloneable reference to the separator, rather than the separator itself.

Examples

Via IntoIterator:

use joinery::{Joinable, JoinItem};

let join = vec![1, 2, 3].join_with(" ");
let mut join_iter = join.into_iter();

assert_eq!(join_iter.next(), Some(JoinItem::Element(1)));
assert_eq!(join_iter.next(), Some(JoinItem::Separator(" ")));
assert_eq!(join_iter.next(), Some(JoinItem::Element(2)));
assert_eq!(join_iter.next(), Some(JoinItem::Separator(" ")));
assert_eq!(join_iter.next(), Some(JoinItem::Element(3)));
assert_eq!(join_iter.next(), None);

Via .iter()

use joinery::{Joinable, JoinItem};

let join = vec![1, 2, 3].join_with(" ");
let mut join_iter = join.iter();

// Note that using .iter() produces references to the separator, rather than clones.
assert_eq!(join_iter.next(), Some(JoinItem::Element(1)));
assert_eq!(join_iter.next(), Some(JoinItem::Separator(&" ")));
assert_eq!(join_iter.next(), Some(JoinItem::Element(2)));
assert_eq!(join_iter.next(), Some(JoinItem::Separator(&" ")));
assert_eq!(join_iter.next(), Some(JoinItem::Element(3)));
assert_eq!(join_iter.next(), None);

Methods

impl<I: Iterator, S> JoinIter<I, S>

pub fn is_sep_next(&self) -> bool

Check if the next iteration of this iterator will (try to) return a separator. Note that this does not check if the underlying iterator is empty, so the next next call could still return None.

Examples

use joinery::{Joinable, JoinItem};

let mut join_iter = (0..3).join_with(", ").into_iter();

assert_eq!(join_iter.is_sep_next(), false);
join_iter.next();
assert_eq!(join_iter.is_sep_next(), true);
join_iter.next();
assert_eq!(join_iter.is_sep_next(), false);

pub fn sep(&self) -> &S

Get a reference to the separator.

pub fn peek(&mut self) -> Option<JoinItem<&I::Item, &S>>

Peek at what the next item in the iterator will be without consuming it. Note that this interface is similar, but not identical, to Peekable::peek.

Examples

use joinery::{Joinable, JoinItem};

let mut join_iter = (0..3).join_with(", ").into_iter();

assert_eq!(join_iter.peek(), Some(JoinItem::Element(&0)));
assert_eq!(join_iter.next(), Some(JoinItem::Element(0)));
assert_eq!(join_iter.peek(), Some(JoinItem::Separator(&", ")));
assert_eq!(join_iter.next(), Some(JoinItem::Separator(", ")));
assert_eq!(join_iter.peek(), Some(JoinItem::Element(&1)));
assert_eq!(join_iter.next(), Some(JoinItem::Element(1)));

pub fn peek_element(&mut self) -> Option<&I::Item>

Peek at what the next non-separator item in the iterator will be without consuming it.

Examples

use joinery::{Joinable, JoinItem};

let mut join_iter = vec!["This", "is", "a", "sentence"].join_with(' ').into_iter();

assert_eq!(join_iter.peek_element(), Some(&"This"));
assert_eq!(join_iter.peek(), Some(JoinItem::Element(&"This")));
assert_eq!(join_iter.next(), Some(JoinItem::Element("This")));

assert_eq!(join_iter.peek_element(), Some(&"is"));
assert_eq!(join_iter.peek(), Some(JoinItem::Separator(&' ')));
assert_eq!(join_iter.next(), Some(JoinItem::Separator(' ')));

assert_eq!(join_iter.peek_element(), Some(&"is"));
assert_eq!(join_iter.peek(), Some(JoinItem::Element(&"is")));
assert_eq!(join_iter.next(), Some(JoinItem::Element("is")));

impl<I: Iterator, S: Clone> JoinIter<I, S>

pub fn normalize<R>(     self ) -> impl Iterator<Item = R> where     I::Item: Into<R>,     S: Into<R>,

Convert the JoinItem elements of a JoinIter into some common type, using Into The type should be one that both the iterator items and the separator can be converted into via Into. Note that, because Into is reflexive, this can be used in cases where the separator and the item are the same type.

Examples

use joinery::Joinable;

// Use this function to aid with type inference
fn assert_str(lhs: Option<&str>, rhs: Option<&str>) {
    assert_eq!(lhs, rhs);
}

let content = vec!["Hello", "World!"];

let join = content.join_with(", ");
let mut iter = join.into_iter().normalize();

assert_str(iter.next(), Some("Hello"));
assert_str(iter.next(), Some(", "));
assert_str(iter.next(), Some("World!"));
assert_str(iter.next(), None);

Trait Implementations

impl<I, S> Debug for JoinIter<I, S> where     I: Iterator + Debug,     S: Debug,     I::Item: Debug,

fn fmt(&self, f: &mut Formatter) -> Result

Formats the value using the given formatter.

impl<I: Iterator, S> From<Join<I, S>> for JoinIter<I, S>

fn from(join: Join<I, S>) -> Self

Performs the conversion.

impl<I, S> Clone for JoinIter<I, S> where     I: Iterator + Clone,     S: Clone,     I::Item: Clone,

fn clone(&self) -> Self

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<I: Iterator, S: Clone> Iterator for JoinIter<I, S>

type Item = JoinItem<I::Item, S>

The type of the elements being iterated over.

fn next(&mut self) -> Option<Self::Item>

Advance to the next item in the Join. This will either be the next element in the underlying iterator, or a clone of the separator.

fn size_hint(&self) -> (usize, Option<usize>)

Returns the bounds on the remaining length of the iterator.

fn fold<B, F>(self, init: B, func: F) -> B where     F: FnMut(B, Self::Item) -> B,

An iterator method that applies a function, producing a single, final value.

fn count(self) -> usize

Consumes the iterator, counting the number of iterations and returning it.

fn last(self) -> Option<Self::Item>

Consumes the iterator, returning the last element.

fn nth(&mut self, n: usize) -> Option<Self::Item>

Returns the nth element of the iterator.

fn step_by(self, step: usize) -> StepBy<Self>

🔬 This is a nightly-only experimental API. (iterator_step_by)

unstable replacement of Range::step_by

Creates an iterator starting at the same point, but stepping by the given amount at each iteration.

fn chain<U>(self, other: U) -> Chain<Self, <U as IntoIterator>::IntoIter> where     U: IntoIterator<Item = Self::Item>,

Takes two iterators and creates a new iterator over both in sequence.

fn zip<U>(self, other: U) -> Zip<Self, <U as IntoIterator>::IntoIter> where     U: IntoIterator,

'Zips up' two iterators into a single iterator of pairs.

fn map<B, F>(self, f: F) -> Map<Self, F> where     F: FnMut(Self::Item) -> B,

Takes a closure and creates an iterator which calls that closure on each element.

fn for_each<F>(self, f: F) where     F: FnMut(Self::Item),

Calls a closure on each element of an iterator.

fn filter<P>(self, predicate: P) -> Filter<Self, P> where     P: FnMut(&Self::Item) -> bool,

Creates an iterator which uses a closure to determine if an element should be yielded.

fn filter_map<B, F>(self, f: F) -> FilterMap<Self, F> where     F: FnMut(Self::Item) -> Option<B>,

Creates an iterator that both filters and maps.

fn enumerate(self) -> Enumerate<Self>

Creates an iterator which gives the current iteration count as well as the next value.

fn peekable(self) -> Peekable<Self>

Creates an iterator which can use peek to look at the next element of the iterator without consuming it.

fn skip_while<P>(self, predicate: P) -> SkipWhile<Self, P> where     P: FnMut(&Self::Item) -> bool,

Creates an iterator that [skip]s elements based on a predicate.

fn take_while<P>(self, predicate: P) -> TakeWhile<Self, P> where     P: FnMut(&Self::Item) -> bool,

Creates an iterator that yields elements based on a predicate.

fn skip(self, n: usize) -> Skip<Self>

Creates an iterator that skips the first n elements.

fn take(self, n: usize) -> Take<Self>

Creates an iterator that yields its first n elements.

fn scan<St, B, F>(self, initial_state: St, f: F) -> Scan<Self, St, F> where     F: FnMut(&mut St, Self::Item) -> Option<B>,

An iterator adaptor similar to [fold] that holds internal state and produces a new iterator.

fn flat_map<U, F>(self, f: F) -> FlatMap<Self, U, F> where     F: FnMut(Self::Item) -> U,     U: IntoIterator,

Creates an iterator that works like map, but flattens nested structure.

fn flatten(self) -> Flatten<Self> where     Self::Item: IntoIterator,

🔬 This is a nightly-only experimental API. (iterator_flatten)

Creates an iterator that flattens nested structure.

fn fuse(self) -> Fuse<Self>

Creates an iterator which ends after the first [None].

fn inspect<F>(self, f: F) -> Inspect<Self, F> where     F: FnMut(&Self::Item),

Do something with each element of an iterator, passing the value on.

fn by_ref(&mut self) -> &mut Self

Borrows an iterator, rather than consuming it.

fn collect<B>(self) -> B where     B: FromIterator<Self::Item>,

Transforms an iterator into a collection.

fn partition<B, F>(self, f: F) -> (B, B) where     B: Default + Extend<Self::Item>,     F: FnMut(&Self::Item) -> bool,

Consumes an iterator, creating two collections from it.

fn try_fold<B, F, R>(&mut self, init: B, f: F) -> R where     F: FnMut(B, Self::Item) -> R,     R: Try<Ok = B>,

An iterator method that applies a function as long as it returns successfully, producing a single, final value.

fn try_for_each<F, R>(&mut self, f: F) -> R where     F: FnMut(Self::Item) -> R,     R: Try<Ok = ()>,

An iterator method that applies a fallible function to each item in the iterator, stopping at the first error and returning that error.

fn all<F>(&mut self, f: F) -> bool where     F: FnMut(Self::Item) -> bool,

Tests if every element of the iterator matches a predicate.

fn any<F>(&mut self, f: F) -> bool where     F: FnMut(Self::Item) -> bool,

Tests if any element of the iterator matches a predicate.

fn find<P>(&mut self, predicate: P) -> Option<Self::Item> where     P: FnMut(&Self::Item) -> bool,

Searches for an element of an iterator that satisfies a predicate.

fn find_map<B, F>(&mut self, f: F) -> Option<B> where     F: FnMut(Self::Item) -> Option<B>,

🔬 This is a nightly-only experimental API. (iterator_find_map)

unstable new API

Applies function to the elements of iterator and returns the first non-none result.

fn position<P>(&mut self, predicate: P) -> Option<usize> where     P: FnMut(Self::Item) -> bool,

Searches for an element in an iterator, returning its index.

fn rposition<P>(&mut self, predicate: P) -> Option<usize> where     P: FnMut(Self::Item) -> bool,     Self: ExactSizeIterator + DoubleEndedIterator,

Searches for an element in an iterator from the right, returning its index.

fn max(self) -> Option<Self::Item> where     Self::Item: Ord,

Returns the maximum element of an iterator.

fn min(self) -> Option<Self::Item> where     Self::Item: Ord,

Returns the minimum element of an iterator.

fn max_by_key<B, F>(self, f: F) -> Option<Self::Item> where     B: Ord,     F: FnMut(&Self::Item) -> B,

Returns the element that gives the maximum value from the specified function.

fn max_by<F>(self, compare: F) -> Option<Self::Item> where     F: FnMut(&Self::Item, &Self::Item) -> Ordering,

Returns the element that gives the maximum value with respect to the specified comparison function.

fn min_by_key<B, F>(self, f: F) -> Option<Self::Item> where     B: Ord,     F: FnMut(&Self::Item) -> B,

Returns the element that gives the minimum value from the specified function.

fn min_by<F>(self, compare: F) -> Option<Self::Item> where     F: FnMut(&Self::Item, &Self::Item) -> Ordering,

Returns the element that gives the minimum value with respect to the specified comparison function.

fn rev(self) -> Rev<Self> where     Self: DoubleEndedIterator,

Reverses an iterator's direction.

fn unzip<A, B, FromA, FromB>(self) -> (FromA, FromB) where     FromA: Default + Extend<A>,     FromB: Default + Extend<B>,     Self: Iterator<Item = (A, B)>,

Converts an iterator of pairs into a pair of containers.

fn cloned<'a, T>(self) -> Cloned<Self> where     Self: Iterator<Item = &'a T>,     T: 'a + Clone,

Creates an iterator which [clone]s all of its elements.

fn cycle(self) -> Cycle<Self> where     Self: Clone,

Repeats an iterator endlessly.

fn sum<S>(self) -> S where     S: Sum<Self::Item>,

Sums the elements of an iterator.

fn product<P>(self) -> P where     P: Product<Self::Item>,

Iterates over the entire iterator, multiplying all the elements

fn cmp<I>(self, other: I) -> Ordering where     I: IntoIterator<Item = Self::Item>,     Self::Item: Ord,

Lexicographically compares the elements of this Iterator with those of another.

fn partial_cmp<I>(self, other: I) -> Option<Ordering> where     I: IntoIterator,     Self::Item: PartialOrd<<I as IntoIterator>::Item>,

Lexicographically compares the elements of this Iterator with those of another.

fn eq<I>(self, other: I) -> bool where     I: IntoIterator,     Self::Item: PartialEq<<I as IntoIterator>::Item>,

Determines if the elements of this Iterator are equal to those of another.

fn ne<I>(self, other: I) -> bool where     I: IntoIterator,     Self::Item: PartialEq<<I as IntoIterator>::Item>,

Determines if the elements of this Iterator are unequal to those of another.

fn lt<I>(self, other: I) -> bool where     I: IntoIterator,     Self::Item: PartialOrd<<I as IntoIterator>::Item>,

Determines if the elements of this Iterator are lexicographically less than those of another.

fn le<I>(self, other: I) -> bool where     I: IntoIterator,     Self::Item: PartialOrd<<I as IntoIterator>::Item>,

Determines if the elements of this Iterator are lexicographically less or equal to those of another.

fn gt<I>(self, other: I) -> bool where     I: IntoIterator,     Self::Item: PartialOrd<<I as IntoIterator>::Item>,

Determines if the elements of this Iterator are lexicographically greater than those of another.

fn ge<I>(self, other: I) -> bool where     I: IntoIterator,     Self::Item: PartialOrd<<I as IntoIterator>::Item>,

Determines if the elements of this Iterator are lexicographically greater than or equal to those of another.

impl<I: FusedIterator, S: Clone> FusedIterator for JoinIter<I, S>

impl<I: TrustedLen, S: Clone> TrustedLen for JoinIter<I, S>