unfoldable

Class of data structures that can be unfolded.

https://github.com/sjoerdvisscher/unfoldable

LTS Haskell 12.26:0.9.6@rev:2
Stackage Nightly 2026-01-09:1.1@rev:3
Latest on Hackage:1.1@rev:3

See all snapshots unfoldable appears in

BSD-3-Clause licensed by Sjoerd Visscher
Maintained by [email protected]
This version can be pinned in stack with:unfoldable-1.1@sha256:ac661c1265553cd3d27467f4853a665a191a7d90c1911dbb7a0bfe37107e68bc,1844

Module documentation for 1.1

Used by 1 package in nightly-2026-01-08(full list with versions):
unfoldable-restricted

Just as there's a Foldable class, there should also be an Unfoldable class.

This package provides one. Example unfolds are:

  • Random values

  • Enumeration of all values (depth-first or breadth-first)

  • Convert from a list

Some examples can be found in the examples directory.

Changes

1.1

  • Updates for GHC 9.6 through 9.14

1.0

  • improved generic implementation of unfold
  • improved implementation of arbitraryDefault
  • lifted QuickCheck upper bound to 3.0
  • updated to containers 0.6

0.9.6

  • updated to one-liner 1.0

0.9.5

  • updated to QuickCheck 2.11

0.9.4

  • updated to QuickCheck 2.10

0.9.3

  • updated to one-liner 0.9

0.9.2

  • use one-liner for the generic implementation of unfold

0.9.1

  • added Nth unfolder
  • added brackets example

0.9

  • added chooseMap method
  • added instances from containers
  • improved ListT instance

0.8.4

  • updated to QuickCheck 2.9

0.8.3

  • updated to transformers 0.5

0.8.2

  • updated to QuickCheck 2.8

0.8.1

  • added changelog
  • updated to transformers 0.4.1.0
  • added Data.Functor.Sum instance for Unfoldable

0.8

  • new implementation of arbitraryDefault