
#12665: Make Read instances faster, and make them fail fast -------------------------------------+------------------------------------- Reporter: dfeuer | Owner: dfeuer Type: feature request | Status: new Priority: high | Milestone: 8.2.1 Component: Core Libraries | Version: 8.0.1 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Runtime | Unknown/Multiple performance bug | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by dfeuer): Let me take that back; I think my modified implementation actually does what Haskell98 says, whereas the current implementation does something else. I don't know for sure what should be considered the correct behavior. P.S., to match the current behavior, we'd need to accept `"122e-"` as an integer, but not `"122e-3"`, because the current implementation lexes `"122e-3"` as a fractional number and thus not an integer, whereas it lexes `"122e-"` as an integer followed by an identifier followed by a symbol. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/12665#comment:6 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler