Reliable, high-performance processing with left-fold enumerators
  • Overview
  • Builds
  • Updates
  • Bugs
  • Contents
  • Changelog
  • Sources


Enumerators are an efficient, predictable, and safe alternative to lazy I/O. Discovered by Oleg Kiselyov, they allow large datasets to be processed in near-constant space by pure code. Although somewhat more complex to write, using enumerators instead of lazy I/O produces more correct programs. This library contains an enumerator implementation for Haskell, designed to be both simple and efficient. Three core types are defined, along with numerous helper functions: * /Iteratee/: Data sinks, analogous to left folds. Iteratees consume a sequence of /input/ values, and generate a single /output/ value. Many iteratees are designed to perform side effects (such as printing to stdout), so they can also be used as monad transformers. * /Enumerator/: Data sources, which generate input sequences. Typical enumerators read from a file handle, socket, random number generator, or other external stream. To operate, enumerators are passed an iteratee, and provide that iteratee with input until either the iteratee has completed its computation, or EOF. * /Enumeratee/: Data transformers, which operate as both enumerators and iteratees. Enumeratees read from an /outer/ enumerator, and provide the transformed data to an /inner/ iteratee.

Active Releases Overview

Release Latest Released Version Version in Testing
{{html release}} 
{{html stable_version}} {{html testing_version}}

Upstream Summary



Koji build ghc-enumerator-0.4.20-2.fc23.ppc64le.rpm signed with sigkey '873529b8'

Details 10 days ago - 2015-08-21 03:47:31


Koji build ghc-enumerator-0.4.20-2.fc23.x86_64.rpm signed with sigkey '81b46521'

Details 16 days ago - 2015-08-15 14:38:37


Koji build ghc-enumerator-0.4.20-2.fc23.src.rpm signed with sigkey '81b46521'

Details 17 days ago - 2015-08-14 07:14:56


Koji build ghc-enumerator-0.4.20-2.fc23.i686.rpm signed with sigkey '81b46521'

Details 19 days ago - 2015-08-12 18:05:57


Koji build ghc-enumerator-0.4.20-2.fc23.armv7hl.rpm signed with sigkey '81b46521'

Details 19 days ago - 2015-08-12 01:04:11

Found a bug? File a ticket. Note: There's some caching going on here. If you expect something and don't see it, check back in 5 minutes.

This Web Site is licensed under the GNU Affero General Public License. You may get sources for the current running code from these repositories: