[project @ 1996-12-19 18:35:23 by simonpj]

[ghc-hetmet.git] / ghc / lib / required / System.lhs

diff --git a/ghc/lib/required/System.hs b/ghc/lib/required/System.lhs
similarity index 68%
rename from ghc/lib/required/System.hs
rename to ghc/lib/required/System.lhs
index 17f8a39..77d82a3 100644 (file)
--- a/ghc/lib/required/System.hs
+++ b/ghc/lib/required/System.lhs
@@ -1,49 +1,69 @@
-{-
 %
-% (c) The GRASP/AQUA Project, Glasgow University, 1995
+% (c) The AQUA Project, Glasgow University, 1994-1996
 %
-\section[LibSystem]{Haskell 1.3 System Interaction}
--}
+
+\section[System]{Module @System@}
+
+\begin{code}
 module System ( 
     ExitCode(ExitSuccess,ExitFailure),
-    getArgs, getProgName, getEnv, system, exitWith ) where
+    getArgs, getProgName, getEnv, system, exitWith
+  ) where
+
+import Foreign         ( Addr )
+import IOBase          ( IOError(..), thenIO_Prim, constructErrorAndFail )
+import ArrBase         ( indexAddrOffAddr )
+import PackedString    ( unpackCString )
+\end{code}
 
-import GHCio
-import GHCps   ( unpackPS, packCString )
-import GHCbase ( indexAddrOffAddr, Addr )
+%*********************************************************
+%*                                                     *
+\subsection{The @ExitCode@ type}
+%*                                                     *
+%*********************************************************
 
-{-
 The $ExitCode$ type defines the exit codes that a program
 can return.  $ExitSuccess$ indicates successful termination;
 and $ExitFailure code$ indicates program failure
 with value {\em code}.  The exact interpretation of {\em code}
 is operating-system dependent.  In particular, some values of 
 {\em code} may be prohibited (e.g. 0 on a POSIX-compliant system).
--}
 
+\begin{code}
 data ExitCode = ExitSuccess | ExitFailure Int 
                 deriving (Eq, Ord, Read, Show)
 
+\end{code}
 
+
+%*********************************************************
+%*                                                     *
+\subsection{Other functions}
+%*                                                     *
+%*********************************************************
+
+\begin{code}
 getArgs                :: IO [String]
 getProgName            :: IO String
 getEnv                 :: String -> IO String
 system                 :: String -> IO ExitCode
 exitWith               :: ExitCode -> IO a
+\end{code}
 
-{-
 Computation $getArgs$ returns a list of the program's command
 line arguments (not including the program name).
--}
+
+\begin{code}
 getArgs = return (unpackArgv ``prog_argv'' (``prog_argc''::Int))
+\end{code}
 
-{-
 Computation $getProgName$ returns the name of the program
 as it was invoked.
--}
+
+\begin{code}
 getProgName = return (unpackProgName ``prog_argv'')
+\end{code}
 
-{-
 Computation $getEnv var$ returns the value
 of the environment variable {\em var}.  
 
@@ -52,15 +72,16 @@ This computation may fail with
 \item $NoSuchThing$
 The environment variable does not exist.
 \end{itemize}
--}
+
+\begin{code}
 getEnv name = 
-    _ccall_ getenv name        `stThen` \ litstring ->
+    _ccall_ getenv name        `thenIO_Prim` \ litstring ->
     if litstring /= ``NULL'' then
-       return (unpackPS (packCString litstring)) -- cheaper than it looks
+       return (unpackCString litstring)
     else
        fail (NoSuchThing ("environment variable: " ++ name))
+\end{code}
 
-{-
 Computation $system cmd$ returns the exit code
 produced when the operating system processes the command {\em cmd}.
 
@@ -73,33 +94,42 @@ Insufficient resources are available to perform the operation.
 \item $UnsupportedOperation$
 The implementation does not support system calls.
 \end{itemize}
--}
+
+\begin{code}
 system "" = fail (InvalidArgument "null command")
 system cmd = 
-    _ccall_ systemCmd cmd      `stThen` \ status ->
+    _ccall_ systemCmd cmd      `thenIO_Prim` \ status ->
     case status of
         0  -> return ExitSuccess
         -1 -> constructErrorAndFail "system"
         n  -> return (ExitFailure n)
 
-{-
+\end{code}
+
 Computation $exitWith code$ terminates the
 program, returning {\em code} to the program's caller.
 Before it terminates, any open or semi-closed handles are first closed.
--}
+
+\begin{code}
 exitWith ExitSuccess = 
-    _ccall_ EXIT (0::Int)      `stThen` \ () ->
+    _ccall_ EXIT (0::Int)      `thenIO_Prim` \ () ->
     fail (OtherError "exit should not return")
 
 exitWith (ExitFailure n) 
   | n == 0 = fail (InvalidArgument "ExitFailure 0")
   | otherwise = 
-    _ccall_ EXIT n             `stThen` \ () ->
+    _ccall_ EXIT n             `thenIO_Prim` \ () ->
     fail (OtherError "exit should not return")
+\end{code}
+
 
-------------------------------------------
--- like unpackCString ...
+%*********************************************************
+%*                                                     *
+\subsection{Local utilities}
+%*                                                     *
+%*********************************************************
 
+\begin{code}
 type CHAR_STAR_STAR    = Addr  -- this is all a  HACK
 type CHAR_STAR         = Addr
 
@@ -113,14 +143,15 @@ unpackArgv argv argc = unpack 1
       = if (n >= argc)
        then ([] :: [String])
        else case (indexAddrOffAddr argv n) of { item ->
-            unpackPS (packCString item) : unpack (n + 1) }
+            unpackCString item : unpack (n + 1) }
 
 unpackProgName argv
   = case (indexAddrOffAddr argv 0) of { prog ->
-    de_slash [] (unpackPS (packCString prog)) }
+    de_slash [] (unpackCString prog) }
   where
     -- re-start accumulating at every '/'
     de_slash :: String -> String -> String
     de_slash acc []      = reverse acc
     de_slash acc ('/':xs) = de_slash []             xs
     de_slash acc (x:xs)          = de_slash (x:acc) xs
+\end{code}