#16403: Add isBinDigit to Data.Char -------------------------------------+------------------------------------- Reporter: hesiod | Owner: (none) Type: feature | Status: new request | Priority: normal | Milestone: Component: | Version: 8.6.4 libraries/base | Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- The {{{Data.Char}}} module contains helper functions that determine whether a Char is a decimal, octal or hexadecimal digit ({{{isDigit}}}, {{{isOctDigit}}}, {{{isHexDigit}}}). A similar helper function for binary digits is not included for no apparent reason (maybe because the number parsers in the {{{Numeric}}} module also don't support binary digits?). The implementation for such a {{{isBinDigit}}} should be trivial, aside from performance considerations: {{{isDigit}}} and friends perform the test using only subtraction and an unsigned comparison, I'm not sure whether {{{isBinDigit}}} offers any different performant implementations. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/16403 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler