# Functional combinators to Standard library

**URL:** <https://forums.swift.org/t/functional-combinators-to-standard-library/43863>\
**Category:** Pitches\
**Tags:** generics, stdlib, functional, containers\
**Created:** [January 15, 2021, 8:33am UTC](https://forums.swift.org/t/functional-combinators-to-standard-library/43863 "2021-01-15T08:33:46Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![maximkrouk](https://sea2.discourse-cdn.com/swift/user_avatar/forums.swift.org/maximkrouk/32/33394_2.png) [@maximkrouk](https://forums.swift.org/u/maximkrouk)\
**Post date:** [January 15, 2021, 8:33am UTC](https://forums.swift.org/t/functional-combinators-to-standard-library/43863/1 "2021-01-15T08:33:47Z")

</div>

This is a draft for a pitch about adding functional types to the standard library. I guess the name of the proposal might change, but the general idea is to collect useful functional combinators, or maybe containers, and to add them to the Standard library.

For now I see 2 main candidates:

- Lens
- Either

Secondary candidates:

- Box (_A container class, providing reference semantics to values_)

Related stuff:  
[Enum composition pitch](https://forums.swift.org/t/pitch-enum-composition/43598/2)  
[Draft proposal](https://github.com/maximkrouk/swift-evolution/blob/main/proposals/0300-functional-combinators-to-standard-library.md)  
[pointfree/swift-prelude](https://github.com/pointfreeco/swift-prelude)