non-empty: List-like structures with static restrictions on the number of elements

[ bsd3, data, library ] [ Propose Tags ]
Versions 0.0, 0.1, 0.1.1, 0.1.2, 0.1.3, 0.2, 0.2.1, 0.3
Dependencies base (==4.*), containers (>=0.4 && <0.6), deepseq (>=1.3 && <1.5), QuickCheck (>=2.1 && <3), utility‑ht (>=0.0.1 && <0.1) [details]
License BSD-3-Clause
Author Henning Thielemann <>
Maintainer Henning Thielemann <>
Category Data
Home page
Source repo this: darcs get --tag 0.3
head: darcs get
Uploaded by HenningThielemann at Thu Sep 1 17:25:58 UTC 2016
Distributions LTSHaskell:0.3, NixOS:0.3, Stackage:0.3, openSUSE:0.3
Downloads 2814 total (27 in the last 30 days)
Rating (no votes yet) [estimated by rule of succession]
Your Rating
  • λ
  • λ
  • λ
Status Docs available [build log]
Last success reported on 2016-09-01 [all 1 reports]
Hackage Matrix CI

We provide the data type NonEmpty that allows to store a list-like structure with at least or exactly n elements, where n is fixed in the type in a kind of Peano encoding and is usually small. The datatype is intended to increase safety by making functions total that are partial on plain lists. E.g. on a non-empty list, head and tail are always defined.

There are more such data types like Optional and Empty. Together with NonEmpty you can define a list type for every finite set of admissible list lengths.

The datatype can be combined with Lists, Sequences and Sets (from the containers package).

The package needs only Haskell 98.

Similar packages:

Related packages:




Maintainer's Corner

For package maintainers and hackage trustees