isPrint does not answer the question "can this character be displayed by
#11529: Show instance of Char should print literals for non-ascii printable charcters -------------------------------------+------------------------------------- Reporter: nushio | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.10.3 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by chak): Replying to [comment:16 allbery_b]: the current user given their current locale?". That would require it to be in IO, and would limit the ability to use it in other contexts.
isPrint answers the question "is the Unicode codepoint contained in the
given Char considered printable by the version of the Unicode standard to which the runtime conforms?".
It is not the correct question to ask here.
It is, however, what the standard prescribes. IMHO it is also the right thing to do as it leads to less unexpected behaviour than the current implementation. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11529#comment:18 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler