I'm getting some weird errors when I try to compile this with GHC, or load it
in GHCi, but it compiles (and runs) just fine using cabal. Here's the file...
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FILE Test.hs:
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module Main where
import Control.Monad.Error ( runErrorT, ErrorT, join, liftIO )
import Data.ConfigFile ( get, CPError, emptyCP, readfile )
data Configuration = Configuration
{
popDir :: FilePath,
username :: String,
sleepTime :: Int
} deriving Show
parseConfig :: ErrorT CPError IO Configuration
parseConfig = do
cp <- join $ liftIO $ readfile emptyCP "/etc/creatur-daemon.conf"
u <- Data.ConfigFile.get cp "DEFAULT" "user"
pd <- Data.ConfigFile.get cp "DEFAULT" "dir"
st <- Data.ConfigFile.get cp "DEFAULT" "sleeptime"
return $ Configuration { popDir = pd, username = u, sleepTime = st }
main :: IO ()
main = do
rv <- runErrorT parseConfig
case rv of
Left (_, msg) -> putStrLn msg
Right config -> print config
**********
When I compile it with ghc, I get the following:
$ ghc -hide-package monads-fd Test.hs
[1 of 1] Compiling Main ( Test.hs, Test.o )
Test.hs:20:9:
No instance for (mtl-1.1.1.1:Control.Monad.Error.Class.MonadError
CPError (ErrorT CPError IO))
arising from a use of `get'
Possible fix:
add an instance declaration for
(mtl-1.1.1.1:Control.Monad.Error.Class.MonadError
CPError (ErrorT CPError IO))
In a stmt of a 'do' expression: st <- get cp "DEFAULT" "sleeptime"
In the expression:
do { cp <- join
$ liftIO $ readfile emptyCP "/etc/creatur-daemon.conf";
u <- get cp "DEFAULT" "user";
pd <- get cp "DEFAULT" "dir";
st <- get cp "DEFAULT" "sleeptime";
.... }
In an equation for `parseConfig':
parseConfig
= do { cp <- join
$ liftIO $ readfile emptyCP "/etc/creatur-daemon.conf";
u <- get cp "DEFAULT" "user";
pd <- get cp "DEFAULT" "dir";
.... }
Test.hs:21:3:
No instance for (Error (CPErrorData, String))
arising from a use of `return'
Possible fix:
add an instance declaration for (Error (CPErrorData, String))
In the expression: return
In the expression:
return $ Configuration {popDir = pd, username = u, sleepTime = st}
In the expression:
do { cp <- join
$ liftIO $ readfile emptyCP "/etc/creatur-daemon.conf";
u <- get cp "DEFAULT" "user";
pd <- get cp "DEFAULT" "dir";
st <- get cp "DEFAULT" "sleeptime";
.... }
I tried adding the instance declarations, but I don't think I did it right
because I then had to add a bunch of imports, and the problems just snowballed.
With this cabal file, I can do "cabal install", and the program compiles and
runs just fine.
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FILE: Creatur.cabal
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Name: Creatur
Version: 2.0
Description: Créatúr
License: OtherLicense
License-file: LICENSE
Author: Amy de Buitléir
Maintainer: amy(a)nualeargais.ie
Build-Type: Simple
Cabal-Version: >=1.2
Executable amy-test
Main-Is: Test.hs
GHC-Options: -Wall -Werror
Build-Depends: base >= 4 && < 5, mtl ==1.1.*, ConfigFile ==1.0.*
**********
Can anyone tell me how to modify the code so it will compile? Thank you in
advance.
