#9231: 7.8 regression in Read instance of Data.Fixed.Pico -------------------------------------+------------------------------------ Reporter: leonbaum2 | Owner: Type: bug | Status: merge Priority: highest | Milestone: 7.8.3 Component: libraries/base | Version: 7.8.2 Resolution: | Keywords: regression Operating System: Unknown/Multiple | Architecture: Unknown/Multiple Type of failure: None/Unknown | Difficulty: Unknown Test Case: | Blocked By: Blocking: | Related Tickets: -------------------------------------+------------------------------------ Comment (by hvr): Replying to [comment:9 Ashley Yakeley]:
Just to clarify, r is not necessarily a power of 10.
Now that you say it, I had the impression an implicit power-of-10 assumption was baked into `Data.Fixed`, for instance consider the following weird behaviour (can be observed in GHC 7.6 as well): {{{ Prelude> import Data.Fixed Prelude Data.Fixed> data B7 Prelude Data.Fixed> instance HasResolution B7 where resolution _ = 128 Prelude Data.Fixed> 1.070 :: Fixed B7 1.062 Prelude Data.Fixed> 1.062 :: Fixed B7 1.054 Prelude Data.Fixed> 1.054 :: Fixed B7 1.046 Prelude Data.Fixed> 1.046 :: Fixed B7 1.039 }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/9231#comment:10 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler