Crate std_x::protected::iter::dependency::itertools

Extra iterator adaptors, functions and macros.

To extend Iterator with methods in this crate, import the Itertools trait:

use itertools::Itertools;

Now, new methods like interleave are available on all iterators:

use itertools::Itertools;

let it = (1..3).interleave(vec![-1, -2]);
itertools::assert_equal(it, vec![1, -1, 2, -2]);

Most iterator methods are also provided as functions (with the benefit that they convert parameters using IntoIterator):

use itertools::interleave;

for elt in interleave(&[1, 2, 3], &[2, 3, 4]) {
    /* loop body */
}

Crate Features

• use_std
  • Enabled by default.
  • Disable to compile itertools using #![no_std]. This disables any items that depend on collections (like group_by, unique, kmerge, join and many more).

Rust Version

This version of itertools requires Rust 1.32 or later.

Modules

__std_iter

Composable external iteration.

structs

The concrete iterator types.

traits

Traits helpful for using certain Itertools methods in generic contexts.

Macros

chain

Chain zero or more iterators together into one sequence.

iproduct

Create an iterator over the “cartesian product” of iterators.

izip

Create an iterator running multiple iterators in lockstep.

Structs

Batching

A “meta iterator adaptor”. Its closure receives a reference to the iterator and may pick off as many elements as it likes, to produce the next iterator element.

Chunk

An iterator for the elements in a single chunk.

Chunks

An iterator that yields the Chunk iterators.

CircularTupleWindows

An iterator over all windows,wrapping back to the first elements when the window would otherwise exceed the length of the iterator, producing tuples of a specific size.

Combinations

An iterator to iterate through all the k-length combinations in an iterator.

CombinationsWithReplacement

An iterator to iterate through all the n-length combinations in an iterator, with replacement.

ConsTuples

An iterator that maps an iterator of tuples like ((A, B), C) to an iterator of (A, B, C).

ExactlyOneError

Iterator returned for the error case of IterTools::exactly_one() This iterator yields exactly the same elements as the input iterator.

FilterMapOk

An iterator adapter to filter and apply a transformation on values within a nested Result::Ok.

FilterOk

An iterator adapter to filter values within a nested Result::Ok.

FlattenOk

An iterator adaptor that flattens Result::Ok values and allows Result::Err values through unchanged.

Format

Format all iterator elements lazily, separated by sep.

FormatWith

Format all iterator elements lazily, separated by sep.

Group

An iterator for the elements in a single group.

GroupBy

GroupBy is the storage for the lazy grouping operation.

GroupingMap

GroupingMap is an intermediate struct for efficient group-and-fold operations. It groups elements by their key and at the same time fold each group using some aggregating operation.

Groups

An iterator that yields the Group iterators.

Interleave

An iterator adaptor that alternates elements from two iterators until both run out.

InterleaveShortest

An iterator adaptor that alternates elements from the two iterators until one of them runs out.

IntersperseWith

An iterator adaptor to insert a particular value created by a function between each element of the adapted iterator.

IntoChunks

ChunkLazy is the storage for a lazy chunking operation.

Iterate

An iterator that infinitely applies function to value and yields results.

KMergeBy

An iterator adaptor that merges an abitrary number of base iterators according to an ordering function.

MergeBy

An iterator adaptor that merges the two base iterators in ascending order. If both base iterators are sorted (ascending), the result is sorted.

MergeJoinBy

An iterator adaptor that merge-joins items from the two base iterators in ascending order.

MultiPeek

See multipeek() for more information.

MultiProduct

An iterator adaptor that iterates over the cartesian product of multiple iterators of type I.

PadUsing

An iterator adaptor that pads a sequence to a minimum length by filling missing elements using a closure.

PeekNth

See peek_nth() for more information.

PeekingTakeWhile

An iterator adaptor that takes items while a closure returns true.

Permutations

An iterator adaptor that iterates through all the k-permutations of the elements from an iterator.

Positions

An iterator adapter to get the positions of each element that matches a predicate.

Powerset

An iterator to iterate through the powerset of the elements from an iterator.

ProcessResults

An iterator that produces only the T values as long as the inner iterator produces Ok(T).

Product

An iterator adaptor that iterates over the cartesian product of the element sets of two iterators I and J.

PutBack

An iterator adaptor that allows putting back a single item to the front of the iterator.

PutBackN

An iterator adaptor that allows putting multiple items in front of the iterator.

RcIter

A wrapper for Rc<RefCell<I>>, that implements the Iterator trait.

RepeatCallDeprecated

See repeat_call for more information.

RepeatN

An iterator that produces n repetitions of an element.

StepDeprecated

An iterator adaptor that steps a number elements in the base iterator for each iteration.

TakeWhileRef

An iterator adaptor that borrows from a Clone-able iterator to only pick off elements while the predicate returns true.

Tee

One half of an iterator pair where both return the same elements.

TupleBuffer

An iterator over a incomplete tuple.

TupleCombinations

An iterator to iterate through all combinations in a Clone-able iterator that produces tuples of a specific size.

TupleWindows

An iterator over all contiguous windows that produces tuples of a specific size.

Tuples

An iterator that groups the items in tuples of a specific size.

Unfold

See unfold for more information.

Unique

An iterator adapter to filter out duplicate elements.

UniqueBy

An iterator adapter to filter out duplicate elements.

Update

An iterator adapter to apply a mutating function to each element before yielding it.

WhileSome

An iterator adaptor that filters Option<A> iterator elements and produces A. Stops on the first None encountered.

WithPosition

An iterator adaptor that wraps each element in an Position.

Zip

See multizip for more information.

ZipEq

An iterator which iterates two other iterators simultaneously

ZipLongest

An iterator which iterates two other iterators simultaneously

Enums

Diff

A type returned by the diff_with function.

Either

The enum Either with variants Left and Right is a general purpose sum type with two cases.

EitherOrBoth

Value that either holds a single A or B, or both.

FoldWhile

An enum used for controlling the execution of fold_while.

MinMaxResult

MinMaxResult is an enum returned by minmax.

Position

A value yielded by WithPosition. Indicates the position of this element in the iterator results.

Traits

Itertools

An Iterator blanket implementation that provides extra adaptors and methods.

MultiUnzip

An iterator that can be unzipped into multiple collections.

PeekingNext

An iterator that allows peeking at an element before deciding to accept it.

Functions

all

Test whether the predicate holds for all elements in the iterable.

any

Test whether the predicate holds for any elements in the iterable.

assert_equal

Assert that two iterables produce equal sequences, with the same semantics as equal(a, b).

chain

Create an iterator that first iterates i and then j.

cloned

Create an iterator that clones each element from &T to T

concat

Combine all an iterator’s elements into one element by using Extend.

cons_tuples

Create an iterator that maps for example iterators of ((A, B), C) to (A, B, C).

diff_with

Compares every element yielded by both i and j with the given function in lock-step and returns a Diff which describes how j differs from i.

enumerate

Iterate iterable with a running index.

equal

Return true if both iterables produce equal sequences (elements pairwise equal and sequences of the same length), false otherwise.

fold

Perform a fold operation over the iterable.

interleave

Create an iterator that interleaves elements in i and j.

intersperse

Iterate iterable with a particular value inserted between each element.

intersperse_with

Iterate iterable with a particular value created by a function inserted between each element.

iterate

Creates a new iterator that infinitely applies function to value and yields results.

join

Combine all iterator elements into one String, seperated by sep.

kmerge

Create an iterator that merges elements of the contained iterators using the ordering function.

kmerge_by

Create an iterator that merges elements of the contained iterators.

max

Return the maximum value of the iterable.

merge

Create an iterator that merges elements in i and j.

merge_join_by

Return an iterator adaptor that merge-joins items from the two base iterators in ascending order.

min

Return the minimum value of the iterable.

multipeek

An iterator adaptor that allows the user to peek at multiple .next() values without advancing the base iterator.

multiunzip

Converts an iterator of tuples into a tuple of containers.

multizip

An iterator that generalizes .zip() and allows running multiple iterators in lockstep.

partition

Partition a sequence using predicate pred so that elements that map to true are placed before elements which map to false.

peek_nth

A drop-in replacement for std::iter::Peekable which adds a peek_nth method allowing the user to peek at a value several iterations forward without advancing the base iterator.

process_results

“Lift” a function of the values of an iterator so that it can process an iterator of Result values instead.

put_back

Create an iterator where you can put back a single item

put_back_n

Create an iterator where you can put back multiple values to the front of the iteration.

rciter

Return an iterator inside a Rc<RefCell<_>> wrapper.

repeat_callDeprecated

An iterator source that produces elements indefinitely by calling a given closure.

repeat_n

Create an iterator that produces n repetitions of element.

rev

Iterate iterable in reverse.

sorted

Sort all iterator elements into a new iterator in ascending order.

unfold

Creates a new unfold source with the specified closure as the “iterator function” and an initial state to eventually pass to the closure

zip

Iterate i and j in lock step.

zip_eq

Iterate i and j in lock step.

Type Definitions

Coalesce

An iterator adaptor that may join together adjacent elements.

Dedup

An iterator adaptor that removes repeated duplicates.

DedupBy

An iterator adaptor that removes repeated duplicates, determining equality using a comparison function.

DedupByWithCount

An iterator adaptor that removes repeated duplicates, while keeping a count of how many repeated elements were present. This will determine equality using a comparison function.

DedupWithCount

An iterator adaptor that removes repeated duplicates, while keeping a count of how many repeated elements were present.

Duplicates

An iterator adapter to filter out duplicate elements.

DuplicatesBy

An iterator adapter to filter for duplicate elements.

GroupingMapBy

GroupingMapBy is an intermediate struct for efficient group-and-fold operations.

Intersperse

An iterator adaptor to insert a particular value between each element of the adapted iterator.

KMerge

An iterator adaptor that merges an abitrary number of base iterators in ascending order. If all base iterators are sorted (ascending), the result is sorted.

MapInto

An iterator adapter to apply Into conversion to each element.

MapOk

An iterator adapter to apply a transformation within a nested Result::Ok.

MapResultsDeprecated

See MapOk.

Merge

An iterator adaptor that merges the two base iterators in ascending order. If both base iterators are sorted (ascending), the result is sorted.