BSD-3-Clause licensed by James Cranch
Maintained by [email protected]
This version can be pinned in stack with:agreeing-,1649

Module documentation for

Depends on 1 package(full list with versions):


A simple data structure helping us ask questions of the following sort: “does all this data have the same /BLANK/ and if so what is it?”

For example:

    doTheseHaveTheSameLength :: [String] -> String
    doTheseHaveTheSameLength l = case foldMap (Somebody . length) of
      Somebody n -> "They all have length " <> show n
      Nobody     -> "The lengths differ"
      Anybody    -> "You didn't give me any strings"

This can of course be done with Maybe (Maybe x) instead, but doing so runs the risk of getting confused: which is Nothing and which is Just Nothing?


Changelog for agreeing

All notable changes to this project will be documented in this file.

The format is based on Keep a Changelog, and this project adheres to the Haskell Package Versioning Policy. - 2023-10-30

  • ADDED: Eq, Ord, Show, Applicative and Monad instances - 2023-03-15

Initial version