#16031: Show instance for Data.Fixed does not show parentheses for negatives -------------------------------------+------------------------------------- Reporter: skeuchel | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: | Version: 8.7 libraries/base | Keywords: Data.Fixed, | Operating System: Unknown/Multiple Show | Architecture: | Type of failure: Incorrect result Unknown/Multiple | at runtime Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- When showing negative numbers most types emit parentheses in precedence level 11 because the result is not atomic: {{{#!hs GHCi, version 8.7.20181015: http://www.haskell.org/ghc/ :? for help Prelude> show (Just (-1 :: Int)) "Just (-1)" Prelude> show (Just (-1 :: Float)) "Just (-1.0)" }}} However, the Show instance for Fixed does not {{{#!hs Prelude> :m Data.Fixed Prelude Data.Fixed> show (Just (-1 :: Fixed E2)) "Just -1.00" Prelude Data.Fixed> }}} I would expect it to, because of consistency and because the result "Just -1.00" is ill-typed when seen as an expression. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/16031 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler