The hinze-streams package

[Tags:bsd3, library]

Numeric instances for infinite streams. An implementation of:

Functional Pearl: Streams and Unique Fixed Points, Ralf Hinze, University of Oxford

Streams, infinite sequences of elements, live in a coworld: they are given by a coinductive data type, operations on streams are implemented by corecursive programs, and proofs are conducted using coinduction. But there is more to it: suitably restricted, stream equations possess unique solutions, a fact that is not very widely appreciated. We show that this property gives rise to a simple and attractive proof technique essentially bringing equational reasoning to the coworld. In fact, we redevelop the theory of recurrences, finite calculus and generating functions using streams and stream operators building on the cornerstone of unique solutions. The development is constructive: streams and stream operators are implemented in Haskell, usually by one-liners. The resulting calculus or library, if you wish, is elegant and fun to use. Finally, we rephrase the proof of uniqueness using generalised algebraic data types.

Along with the usual instances for infinite streams, this provides: Num, Enum, Real, Fractional, as well as recurrences on streams, finite calculus, generators


Versions 1.0
Dependencies base, haskell98, Stream [details]
License BSD3
Author Ralf Hinze
Maintainer Don Stewart <>
Stability experimental
Category Data
Home page
Uploaded Sun May 3 21:25:11 UTC 2009 by DonaldStewart
Distributions NixOS:1.0
Downloads 403 total (5 in the last 30 days)
0 []
Status Docs uploaded by user
Build status unknown [no reports yet]




Maintainer's Corner

For package maintainers and hackage trustees