casualjim / hie

A library for working with iterators through streaming combinators

Hie

hasten ye collection operations

Hie contains a generic iterable with several functional combiner methods.

This library is built around the concept of an Iterable which is a very small interface that allows for lazy iteration over a sequence of values. With this you can combine many filter, map and flatmap invocations and they will only be evaluated when the first Next method is called.

You can interrupt both ForEach and Fold so you can stop iterating and throw away the rest of the results.

type Iter[T any] interface {
 HasNext() bool
 Next() T
}

You can find iter implementations for a slice and an option value.

There is support for clonable iterators, if the iterator implements a Clone() method that returns a single value that is either an Iter[T] or a type that implements Iter[T] then you can use the iter.Clone(iterator) method.

Combiner

• Map
• Filter
• FilterMap
• FlatMap
• Flatten
• Union: return the unique elements contained in the provided iterators
• Intersect: return the intersection of 2 iterators
• Concat: combine several iterators into 1
• TakeN: take the first n items of an iterator
• Cloned: if the element of the iterator is cloneable it returns an iterator that clones every element

Terminators

• ForEach
• Fold
• Collect
• Difference
• Symmetric Difference
• Find: return an option with the first matching value
• First: return the first element of a collection as an option

Option

This library also contains an Option type that can be used with the same combinators.

Channel

This library contains an Iter implementation that's backed by a channel

What's next

If I ever find time or the will to add

• an Either type
• a Result type (left biased either)
• function composition
• ...