Attached is a patch of what I did to my Posix.lhs. The problem is that
'getEnvVar' will throw an exception when the variable is not present in the
environment. Thus, I'm proposing 'mayGetEnvVar', which will return
Nothing | Just String. I can't think of a reason why anyone would want to use
the old version :) [And it even won't break things.]
First I tried hiding PosixProcPrim.getEnvVar to make my getEnvVar the new
default, but this would have been too tedious since I'd have had to rewrite the
exports-part of Posix.lhs (can't have 'hiding'/'qualified' there).
Volker (who still tries to learn diffing/patching)
--
Volker Stolz * [EMAIL PROTECTED] * PGP
*** Posix.lhs Fri Mar 17 12:32:19 2000
--- Posix.lhs Fri Mar 17 12:10:50 2000
***************
*** 16,21 ****
runProcess,
- mayGetEnvVar,
-
ByteCount,
Fd, intToFd,
--- 16,19 ----
***************
*** 48,53 ****
import PosixUtil
- import Exception
-
-- [OLD COMMENT:]
-- runProcess is our candidate for the high-level OS-independent primitive
--- 46,49 ----
***************
*** 114,120 ****
return ()
- mayGetEnvVar :: String -> IO (Maybe String)
- mayGetEnvVar var = do
- catchAllIO (PosixProcPrim.getEnvVar var >>= (\x -> return (Just x))) -- can only
be NoSuchThing
- (\_ -> return Nothing)
\end{code}
--- 110,112 ----
