ghc-typelits-extra

Additional type-level operations on GHC.TypeLits.Nat

http://www.clash-lang.org/

Version on this page:0.2.3
LTS Haskell 24.18:0.4.8
Stackage Nightly 2025-11-04:0.5.1
Latest on Hackage:0.5.1

See all snapshots ghc-typelits-extra appears in

BSD-2-Clause licensed by Christiaan Baaij
Maintained by [email protected]
This version can be pinned in stack with:ghc-typelits-extra-0.2.3@sha256:a880c666bc10eebe42be28789eb1c51a0133127d3ac05d68dc4a584c82f5cb98,4755

Module documentation for 0.2.3

ghc-typelits-extra

Build Status Hackage Hackage Dependencies

Extra type-level operations on GHC.TypeLits.Nat and a custom solver implemented as a GHC type-checker plugin:

  • GHC.TypeLits.Extra.Max: type-level max
  • GHC.TypeLits.Extra.Min: type-level min
  • GHC.TypeLits.Extra.Div: type-level div
  • GHC.TypeLits.Extra.Mod: type-level mod
  • GHC.TypeLits.Extra.FLog: type-level equivalent of integerLogBase# .i.e. the exact integer equivalent to “floor (logBase x y)”
  • GHC.TypeLits.Extra.CLog: type-level equivalent of the ceiling of integerLogBase# .i.e. the exact integer equivalent to “ceiling (logBase x y)”
  • ‘GHC.TypeLits.Extra.Log’: type-level equivalent of <https://hackage.haskell.org/package/integer-gmp/docs/GHC-Integer-Logarithms.html#v:integerLogBase-35- integerLogBase#> where the operation only reduces when “floor (logBase b x) ~ ceiling (logBase b x)”
  • GHC.TypeLits.Extra.GCD: a type-level gcd
  • GHC.TypeLits.Extra.LCM: a type-level lcm

Changes

Changelog for the ghc-typelits-extra package

0.2.3 May 15th 2017

  • Support GHC 8.2
  • Max, Min, GCD, and LCM now have a commutativity property #9
  • Reduce GCD 0 x to x #9
  • Reduce GCD 1 x to 1 #9
  • Reduce GCD x x to x #9
  • Reduce LCM 0 x to 0 #9
  • Reduce LCM 1 x to x #9
  • Reduce LCM x x to x #9
  • Reduce Max (0-1) 0 to 0 #10
  • Reduce Min (0-1) 0 to 0 - 1 #10
  • Fixes bugs:
    • Solver turns LCM into GCD #8
    • Solver turns Max into Min

0.2.2 January 15th 2017

  • Reduce Min n (n+1) to n
  • Reduce Max n (n+1) to n+1
  • Reduce cases like 1 <=? Div 18 6 to True
  • Add a type-level division that rounds up: type DivRU n d = Div (n + (d - 1)) d
  • Add a type-level divMod : DivMod :: Nat -> Nat -> '(Nat, Nat)

0.2.1 September 29th 2016

  • Reduce Max n n to n
  • Reduce Min n n to n

0.2 August 19th 2016

  • New type-level operations:
    • Max: type-level max
    • Min: type-level min
    • Div: type-level div
    • Mod: type-level mod
    • FLog: floor of logBase
    • Log: exact integer logBase (i.e. where floor (logBase b x) ~ ceiling (logBase b x) holds)
    • LCM: type-level lcm
  • Fixes bugs:
    • CLog b 1 doesn’t reduce to 0

0.1.3 July 19th 2016

  • Fixes bugs:
    • Rounding error in CLog calculation

0.1.2 July 8th 2016

  • Solve KnownNat constraints over CLog and GCD, i.e., KnownNat (CLog 2 4)

0.1.1 January 20th 2016

  • Compile on GHC 8.0+

0.1 October 21st 2015

  • Initial release