tandem-hs

Haskell implementation of Tandem8x32. It produces the stream of the specification bit for bit. Bounded integers, normals and exponentials equal tandem-c's fixtures bit for bit. Fills of 1024 or more elements run a vendored tandem.c, and smaller fills and scalar draws are pure Haskell.

• API: the Tandem type, its draws and fills, and the random instances.
• Design: the fills, bounded integers, normals, exponentials and fused multiply-adds.
• Tests: what the suite checks, the fixtures, and what CI runs.
• Performance: Apple M4 figures against StdGen and mwc-random.

Install

-- cabal.project
source-repository-package
  type: git
  location: https://github.com/tandem-rng/tandem-hs

GHC 9.12 or newer, GHC2024. The library depends on base, primitive, vector and random, and compiles cbits/tandem.c, vendored from tandem-c 1c75956, with the C compiler GHC uses.

AI assistance

This port was written with the help of large language models under human direction. The design and the specification are human work, as is much of the Julia implementation. The code is tested bit for bit against every vector of the specification and against long stream dumps from the Julia implementation, and every value must match. The output does not depend on who or what wrote the code.