If you enter :set +s in GHCi, then timing and memory info will be printed after the evaluation of every expression. Example: Prelude> :set +s Prelude> sum [1..2^20] 549756338176 it :: (Num a, Enum a) => a (0.34 secs, 169,197,008 bytes) Note that this will be the timing of the expression as evaluated in the … Read more
I investigated accelerate and accelerate-cuda and put some debug code to measure a time both under ghci and in a compiled, optimised version. Results are below, you can see stack trace and execution times. ghci run $ ghc -O2 -dynamic -c -threaded Main.hs && ghci GHCi, version 7.8.3: http://www.haskell.org/ghc/ 😕 for help … Loading package … Read more
You need ghci -package such-and-such And to double-check that such-and-such is truly visible to GHC, run ghc-pkg list | grep such-and-such.
How to get GHCi to load the opengl package under GHC 7.6.1 x86-64 Windows 7?
I would try to make a standalone preprocessor that runs SO preprocessing code or the standard literary preprocessor, depending on file extension. Then just use :set -pgmL SO-preprocessor in ghci.conf. For the standard literary preprocessor, run the unlit program, or use Distribution.Simple.PreProcess.Unlit. This way, :load and filename completion just work normally. GHCI passes 4 arguments … Read more
EDIT: Actually, I’m no longer sure. Several versions later, it seems that GLFW no longer works in GHCi on OS X. It turns out that GLFW+OpenGL fulfills all four requirements! You need to invoke ghci with ghci -framework Carbon. You need the EnableGUI.hs file, which you can get here. Note that you can’t load it … Read more
System.Directory.getCurrentDirectory from the directory package.
The instance declaration you made is the correct way to go. It seems you forgot to remove that faulty deriving clause from the original data declaration. data Operace = Op (Int->Int->Int) String (Int->Int->Int) instance Show Operace where show (Op op str inv) = show str
When you use import ModuleName in GHCi, it works (mostly) in the same way import Data.List works: GHC checks your local package database for the module, loads it, and brings its (exported) contents into scope. However, Geometry isn’t a module of a package installed with ghc-pkg. Therefore, GHC doesn’t know that a module Geometry exists … Read more
titaniumdecoy, I remember being helped with this sort of GHCi mystery when I learned the frequently made point that writing things like ‘let square x = x * x’ inside the GHCi is like writing let a = f b with do notation in the IO monad — say in this sort of example: palindromize … Read more