class Extensions

package itertools

@:directlyUsed

Extension functions to provide a fluent iterator API. Use with:

using itertools.Extensions;

Static methods

staticall<T>(it:Iterable<T>, pred:T ‑> Bool):Bool

Checks, if a given predicate is true for all elements of an iterable.

Parameters:

it

The iterable that contains the elements to check the predicate for.

Returns:

true, if all elements of it returned true for pred, false otherwise.

staticany<T>(it:Iterable<T>, pred:T ‑> Bool):Bool

Checks, if a given predicate is true for any element of an iterable.

Parameters:

it

The iterable that contains the elements to check the predicate for.

Returns:

true, if any element of it returned true for pred, false otherwise.

staticasIterable<T>(it:Iterable<T>):Iterable<T>

Utility to cast an iterable type to an Iterable<T>.

Useful, if using the extension functions like map on an Array, so the extension is invoked instead of the built-in.

staticasOnceIterable<T>(it:Iterator<T>):Iterable<T>

Utility to cast an iterator to an Iterable<T>.

Useful for things like using Map<T>.keys() to use in the API.

staticchain<T>(it1:Iterable<T>, it2:Iterable<T>):Iterable<T>

Chains together 2 iterables one after the other.

Parameters:

it1

The first iterable in the chain.

it2

The second iterable to chain.

Returns:

An iterable that first contains the elements of it1, then the elements of it2.

staticcount<T>(it:Iterable<T>):Int

Counts the number of elements in an iterable.

Parameters:

it

The iterable to count the number of elements of.

Returns:

The number of elements in it.

staticenumerate<T>(it:Iterable<T>):Iterable<Indexed<T>>

Adds the 0-based index for each element of an iterable.

Parameters:

it

The iterable to add the index of each element for.

Returns:

The iterable that contains each element of it in an Indexed.

staticfilter<T>(it:Iterable<T>, pred:T ‑> Bool):Iterable<T>

Filters the elements of an iterable using a predicate.

Parameters:

it

The iterable to filter the elements of.

pred

The filtering predicate.

Returns:

The iterable that uses pred to filter the elements of it.

staticfilterMap<T, U>(it:Iterable<T>, f:T ‑> Option<U>):Iterable<U>

Filters and maps an iterable by transforming to an Optional<U>, and only keeping Some(U).

Parameters:

it

The iterable to filter and map.

f

The function to use for transforming.

Returns:

The iterable that maps and filters it with f.

staticfind<T>(it:Iterable<T>, pred:T ‑> Bool):Option<T>

Attempts to find the first element in an iterable that matches the given predicate.

Parameters:

it

The iterable to search.

pred

The predicate to search elements with.

Returns:

The first element of it, where pred returns true, None otherwise.

staticfirst<T>(it:Iterable<T>):Option<T>

Retrieves the first element of an iterable, if any.

Parameters:

it

The iterable to retrieve the first element of.

Returns:

The first element of it, or None, if it was empty.

staticflatMap<T, U>(it:Iterable<T>, f:T ‑> Iterable<U>):Iterable<U>

Maps the elements of an iterator to multiple other elements that get flattened.

Parameters:

it

The iterable elements to map.

f

The function to transform the elements.

Returns:

The elements of it, transformed by f, flattened into a single iterable.

staticflatten<T>(it:Iterable<Iterable<T>>):Iterable<T>

Flattens a nested iterable structure.

Parameters:

it

The nested iterable to flatten.

Returns:

The flattened elements of it, containing each element of each iterable in it.

staticfoldl<T, U>(it:Iterable<T>, seed:U, acc:(U, T) ‑> U):U

Accumulates the elements of an iterable from left to right.

Parameters:

it

The iterable that is fed into the accumulator.

seed

The initial partial result.

acc

The accumulator function.

Returns:

The result of the accumulation.

@:genericstaticgroupBy<K, T>(it:Iterable<T>, keySel:T ‑> K):Iterable<Grouping<K, T>>

Groups the elements of an iterable.

Parameters:

it

The iterable to group the elements of.

keySel

The selector function that selects the grouping key for each element.

Returns:

An iterable that contains the groups constructed from the elements of it with the group key selected with keySel in Groupings.

staticjoin<T>(it:Iterable<T>, sep:String):String

Joins iterable elements with a separator into a string.

The elements are added using StringBuf.add.

Parameters:

it

The iterable to join the elements of.

sep

The separator string.

Returns:

The items of it joined into a String, separated by sep.

staticlast<T>(it:Iterable<T>):Option<T>

Retrieves the last element of an iterable, if any.

Parameters:

it

The iterable to retrieve the last element of.

Returns:

The last element of it, or None, if it was empty.

staticmap<T, U>(it:Iterable<T>, f:T ‑> U):Iterable<U>

Maps the elements of an iterable using a transformer function.

Parameters:

it

The iterable to transform the elements of.

f

The transformer function.

Returns:

The iterable that uses f to transform each element of it.

staticnth<T>(it:Iterable<T>, n:Int):Option<T>

Retrieves the nth element of an iterable, if any.

Parameters:

it

The iterable to retrieve the nth element of.

n

The 0-based index of the element to retrieve.

Returns:

The nth element of it, or None, if it was empty.

staticreverse<T>(it:Iterable<T>):Iterable<T>

Reverses an iterable.

Parameters:

it

The iterable to reverse.

Returns:

An iterable that contains the elements of it, but in reverse order.

staticscanl<T, U>(it:Iterable<T>, seed:U, acc:(U, T) ‑> U):Iterable<U>

Repeatedly applies an accumulator function for the partial result and the next element of an iterable.

Parameters:

it

The iterable that is fed into the accumulator.

seed

The initial partial result.

acc

The accumulator function.

Returns:

An iterable that contains each element of the accumulation.

staticskip<T>(it:Iterable<T>, n:Int):Iterable<T>

Skips the first n elements of an iterable.

Parameters:

it

The iterable to skip the first n elements of it.

n

The amount of elements to skip.

Returns:

An iterable that misses the first n elements of it.

staticskipWhile<T>(it:Iterable<T>, pred:T ‑> Bool):Iterable<T>

Skips the first elements of an iterable, while a predicate is true for the elements.

    @param it The iterable to skip the first elements of `it`.
    @param pred The predicate to use when skipping elements.
    @returns An iterable that misses the first elements of `it`, while

pred returns true.

statictake<T>(it:Iterable<T>, n:Int):Iterable<T>

Only keeps the first n elements of an iterable.

Parameters:

it

The iterable to keep the first n elements of it.

n

The amount of elements to keep.

Returns:

An iterable that only keeps the first n elements of it.

statictakeWhile<T>(it:Iterable<T>, pred:T ‑> Bool):Iterable<T>

Only keeps the first elements of an iterable, while a predicate is true for the elements.

Parameters:

it

The iterable to keep the first elements of it.

pred

The predicate to use when keeping elements.

Returns:

An iterable that keeps the first elements of it, while pred returns true.

statictoArray<T>(it:Iterable<T>):Array<T>

Collects the elements of an iterable to an Array.

Parameters:

it

The iterable to collect the elements of.

Returns:

The items of it collected into an Array.

@:genericstatictoMap<T, K>(it:Iterable<T>, keySel:T ‑> K):Map<K, T>

Collects the elements of an iterable to a Map with a given key selector.

Parameters:

it

The iterable to collect the elements of.

keySel

The function to select the key from the elements of it.

Returns:

The items of it collected into a Map.

@:genericstatictoMapProj<T, K, V>(it:Iterable<T>, keySel:T ‑> K, valSel:T ‑> V):Map<K, V>

Collects the elements of an iterable to a Map with a given key and value selector.

Parameters:

it

The iterable to collect the elements of.

keySel

The function to select the key from the elements of it.

valSel

The function to select the value from the elements of it.

Returns:

The items of it collected into a Map.

staticzip<T, U>(it1:Iterable<T>, it2:Iterable<U>):Iterable<Pair<T, U>>

Zips together 2 iterables to have a pair iterable.

Parameters:

it1

The first iterable to zip.

it2

The second iterable to zip.

Returns:

An iterable that zips together the elements of it1 and it2 into a Pair.