GHCI Failed to load interface for ‘System.Time’ - haskell

Question

I am learning Haskell and trying to build an example from the book.
When I load the code using ":l BetterPredicate" command in GHCI, I am getting following error:
Prelude> :l BetterPredicate
[1 of 2] Compiling RecursiveContents ( RecursiveContents.hs, interpreted )
RecursiveContents.hs:12:32: warning: [-Wtabs]
Tab character found here.
Please use spaces instead.
[2 of 2] Compiling Main ( BetterPredicate.hs, interpreted )
BetterPredicate.hs:3:1: error:
Failed to load interface for ‘System.Time’
Perhaps you meant
System.CPUTime (from base-4.9.1.0)
System.Cmd (from process-1.4.3.0)
System.Mem (from base-4.9.1.0)
Use -v to see a list of the files searched for.
Failed, modules loaded: RecursiveContents.
Here is the code I am trying to compile:
import Control.Monad (filterM)
import System.Directory (Permissions (..), getModificationTime, getPermissions)
import System.Time (ClockTime(..))
import System.FilePath (takeExtension)
import Control.Exception (bracket, handle)
import System.IO (IOMode(..), hClose, hFileSize, openFile)
-- Our functions
import RecursiveContents (getRecursiveContents)
type Predicate = FilePath -- Path to directory entry
-> Permissions -- permissions
-> Maybe Integer -- file size (Nothing if not file)
-> ClockTime -- last modified
-> Bool
-- TBD
getFileSize :: FilePath -> IO (Maybe Integer)
betterFind :: Predicate -> FilePath -> IO [FilePath]
betterFind p path = getRecursiveContents >>= filterM check
where check name = do
perms <- getPermissions name
size <- getFileSize name
modified <- getModificationTime name
return (p name perms size modified)
simpleFileSize :: FilePath -> IO Integer
simpleFileSize path = do
h <- openFile path ReadMode
size <- hFileSize h
hClose
return size
saferFileSize :: FilePath -> IO (Maybe Integer)
saferFileSize path = handle (\_ -> return Nothing) $ do
h <- openFile path ReadMode
size <- hFileSize h
hClose
return (Just size)
getFileSize :: FilePath -> IO (Maybe Integer)
getFileSize path = handle (\_ -> return Nothing) $
bracket (openFile path ReadOnly) hClose $ \h -> do
size <- hFileSize h
hClose
return (Just size)
type InfoP a = FilePath -- path to directory entry
-> Permissions -- permissions
-> Maybe Integer -- file size (Nothing if not file)
-> ClockTime -- last modified
-> a
pathP :: InfoP FilePath
pathP path _ _ _ = path
sizeP :: InfoP Integer
sizeP _ _ (Just size) _ = size
sizeP _ _ Nothing _ = -1
equalP :: (Eq a) => InfoP a -> a -> InfoP Bool
--equalP f k = \w x y z -> f w x y z == k
equalP f k w x y z = f w x y z == k
According to the documentation: http://hackage.haskell.org/package/old-time-1.1.0.3/docs/System-Time.html this module is part of old-time library, so I suppose I need to import it somehow, but I am not sure how to do it if I am not building a package using Cabal (there is no *.cabal file) or something else, I just want to use my code in GHCI.

Answer 1

Just use cabal install to install a package globally
$ cabal install old-time
It will give you a warning, but that's ok if you are just using it for ghci support.
Also note the documentation warns:
This library is deprecated, please look at Data.Time in the time package instead.