#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: #5692 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by JulianLeviston): The current problems are: ##Problem 1## As we need to store an application of `mkRational` upon desugaring, we need to have it exist in some library. Unfortunately, for Stage 1 compilation, the library functions we have access to seem to be only those that exist in the *GHC that is compiling* rather than the *GHC that is being compiled*. This means the reference to `mkRationalName` that I've added to `PrelNames.hs` doesn't work, because we can't refer to any module that has the `mkRational` function in it; none exist. Of course, there is every chance we're not aware of a way to inject the bootstrapped code in — how does one refer to new library functions? Note: initially, and in the current fork as I've written it, I refer to it via `gHC_REAL` but that obviously doesn't work. ##Problem 2## Typechecking is still slow (less slow, granted, but only a little). I think this makes sense, as I haven't actually adjusted any typechecker code yet. I've been looking into `TcExpr.hs` which has the `tcExpr` function, but I need to figure through that code. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/15646#comment:67 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler