Data.Array.ST.Iterator

data Iterator r a

This type provides a slightly easier way of iterating over an array's elements in an STArray computation, without having to keep track of indices.

iterator :: forall r a. (Int -> Maybe a) -> ST r (Iterator r a)

Make an Iterator given an indexing function into an array (or anything else). If xs :: Array a, the standard way to create an iterator over xs is to use iterator (xs !! _), where (!!) comes from Data.Array.

iterate :: forall r a. Iterator r a -> (a -> ST r Unit) -> ST r Unit

Perform an action once for each item left in an iterator. If the action itself also advances the same iterator, iterate will miss those items out.

next :: forall r a. Iterator r a -> ST r (Maybe a)

Get the next item out of an iterator, advancing it. Returns Nothing if the Iterator is exhausted.

peek :: forall r a. Iterator r a -> ST r (Maybe a)

Get the next item out of an iterator without advancing it.

exhausted :: forall r a. Iterator r a -> ST r Boolean

Check whether an iterator has been exhausted.

pushWhile :: forall r a. (a -> Boolean) -> Iterator r a -> STArray r a -> ST r Unit

Extract elements from an iterator and push them on to an STArray for as long as those elements satisfy a given predicate.

pushAll :: forall r a. Iterator r a -> STArray r a -> ST r Unit

Push the entire remaining contents of an iterator onto an STArray.