
#15646: ghci takes super long time to find the type of large fractional number -------------------------------------+------------------------------------- Reporter: Johannkokos | Owner: | JulianLeviston Type: bug | Status: new Priority: normal | Milestone: 8.6.1 Component: GHCi | Version: 8.4.3 Resolution: | Keywords: newcomer Operating System: Unknown/Multiple | Architecture: Type of failure: Compile-time | Unknown/Multiple performance bug | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by osa1): Hmm, I'm not sure if doing parsing in runtime is a good idea. Why not do the parsing in compile time generate Core for this instead: {{{ (X GHC.Real.% 1) GHC.Num.* (10 :: Integer) GHC.Real.^^ Y }}} for `XeY`? Now the huge `Integer` will be computed in runtime but we won't be doing parsing. I just realized that this is basically desugaring `XeY` to `(X%1) * 10^^Y`, similar to the idea in comment:20 except we don't ask users to write this, instead we convert the `XeY` notation to the other. Simon, any opinions on this? -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/15646#comment:23 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler