NEWS

# itertools 0.1.3

## Miscellaneous

* `icount()` now has an optional `stop` argument. By default, the sequence is
  neverending.

# itertools 0.1.2

## Iterators

* `icombinations()`: Iterator that generates all combinations of a vector of
  length `n` taken `m` at a time. By default, the combinations are **without
  replacement** so that elements are not repeated. To generate combinations
  **with replacement**, set `replacement=TRUE`.

* `ipermutations()`: Iterator that returns all permutations of a vector.

* `itripletwise()`: Iterator that returns elements of an object in triplets.

## Miscellaneous

* `iproduct()` can now repeat a Cartesian product multiple times with the
  `times` argument. By default, repeated only once.

# itertools 0.1.1

## Iterators

* `ichunk()`: Iterator that returns elements in fixed-length chunks. If the
  length of the iterator is not divisible by `chunk_size`, the remainder of the
  last block is filled with the value specified in `fill`.

* `ipad()`: Iterator that returns an object followed indefinitely by a `fill`
  value.

* `ipairwise()`: Iterator that returns elements of an object in pairs.

* `iroundrobin()`: Iterator that traverses each given iterable in a roundrobin
  order.

* `itabulate()`: Iterator that maps a function to a sequence of numeric values.

* `iunique()`: Iterator that extracts the unique elements from an iterable
  object. This function is an iterator analogue to base::unique.

* `iunique_justseen()`: Iterator that extracts the just-seen unique elements
  from an iterable object. Only the element just seen is remembered for
  determining uniqueness.

## Utilities

* `consume()`: Consumes the first n elements of an iterator.

* `dotproduct()`: Computes the dot product of two iterable objects.

* `iter_deepcopy()`: Performs a deep copy of an iterator.

* `nth()`: Returns the nth item of an iterator, skipping the iterator ahead
  during the process. If the iterator is entirely consumed, a default value is
  returned.

* `quantify()`: Count the number of times an iterable object is TRUE.

* `take()`: Return the first n elements of an iterable object as a list.

## Miscellaneous

* Fixed a rare issue where `ichain()` was throwing an uncaught exception.

* Resolved an issue with `itee()` when applied to an iterator. Shallow copies
  were being made, such that each shared a common `state`. The introduction of
  `iter_deepcopy()` resolved this issue, closing Issue #36.

# itertools 0.1

## Iterators

* `ichain()`: Chains multiple arguments together into a single iterator.
  Generates an iterator that returns elements from the first argument until it
  is exhausted. Then generates an iterator from the next argument and returns
  elements from it. This process continues until all arguments are exhausted.
  Chaining is useful for treating consecutive sequences as a single sequence.

* `icompress()`: Iterator that filters elements where corresponding selector is
  false. Returns only those elements for which the corresponding 'selector' is
  `TRUE`.

* `icount()`: Neverending numeric sequence with initial value and step size.

* `icycle()`: Iterator that cycles indefinitely through an iterable object

* `idropwhile()`: Iterator that drops elements until the predicate function
  returns `FALSE`.

* `ienum()`: Alias to `ienumerate()` to save a few keystrokes.

* `ienumerate()`: Iterator that returns the elements of an object along with
  their indices. This function is intended to follow the convention used in
  Python's `enumerate` function.

* `ifilter()`: Iterator that filters elements not satisfying a predicate
  function. Returns only those elements for which the predicate function is
  `TRUE`.

* `ifilterfalse()`: Iterator that filters elements not satisfying a predicate
  function. Returns only those elements for which the predicate function is
  `FALSE`.

* `imap()`: Iterator that applies a given function to several iterables
  concurrently.

* `iproduct()`: Iterator that returns the Cartesian product of the
  arguments. Similar to `base::expand.grid()`.

* `irep()`: Iterator that replicates elements of an iterable object. Follows the
  `base::rep()` function.

* `irep_len()`: Iterator that replicates elements of an iterable object with a
  desired length. Follows the `base::rep_len()` function.

* `irepeat()`: Iterator that returns an object indefinitely unless a specified
  number of times is given.

* `iseq()`: Iterator for sequence generation. Follows the base `seq()` function.

* `iseq_along()`: Iterators for sequence generation of length equal to an
  object. Follows the `base::seq_along()` function.

* `iseq_len()`: Iterators for sequence generation of a fixed length. Follows the
  `base::seq_len()` function.

* `islice()`: Iterator that returns selected elements from an iterable.

* `istar()`: Alias to `istarmap()` to save a few keystrokes.

* `istarmap()`: Iterator that applies a given function to the elements of an
  iterable.

* `itakewhile()`: Iterator that returns elements while a predicate function
  returns `TRUE`.

* `itee()`: Returns a list of n independent iterators from a single iterable
  object.

* `izip()`: Iterator that iterates through several iterables concurrently.

* `izip_longest()`: Iterator that iterates through several iterables
  concurrently. Missing values are replaced with the value given in `fill` if
  the iterables are of uneven length.