[commit: Cabal] master: Actually write some fields to the config file. (e16f93c)

[Ian Lynagh]

Repository : ssh://darcs.haskell.org//srv/darcs/packages/Cabal

On branch  : master

http://hackage.haskell.org/trac/ghc/changeset/e16f93c1eb373e4bbe96cb803978aa5fef3cc9fc

>---------------------------------------------------------------

commit e16f93c1eb373e4bbe96cb803978aa5fef3cc9fc
Author: bjorn <bjorn at bringert.net>
Date:   Sun Oct 7 09:04:30 2007 +0000

    Actually write some fields to the config file.

>---------------------------------------------------------------

 .../src/Network/Hackage/CabalInstall/Config.hs     |   17 +++++++++++++----
 .../src/Network/Hackage/CabalInstall/Utils.hs      |    5 +++++
 2 files changed, 18 insertions(+), 4 deletions(-)

diff --git a/cabal-install/src/Network/Hackage/CabalInstall/Config.hs b/cabal-install/src/Network/Hackage/CabalInstall/Config.hs
index 50bdb71..0fb2fcd 100644
--- a/cabal-install/src/Network/Hackage/CabalInstall/Config.hs
+++ b/cabal-install/src/Network/Hackage/CabalInstall/Config.hs
@@ -181,7 +181,8 @@ loadConfig configFile =
        minp <- readFileIfExists configFile
        case minp of
          Nothing -> do hPutStrLn stderr $ "Config file " ++ configFile ++ " not found."
-                       writeDefaultConfigFile configFile
+                       hPutStrLn stderr $ "Writing default configuration to " ++ configFile ++ "."
+                       writeDefaultConfigFile configFile defaultConf
                        return defaultConf
          Just inp -> case parseBasicStanza configFieldDescrs defaultConf inp of
                        ParseOk ws dummyConf -> 
@@ -200,12 +201,20 @@ loadConfig configFile =
                               return defaultConf
 
 -- FIXME: finish this
-writeDefaultConfigFile :: FilePath -> IO ()
-writeDefaultConfigFile file = 
-    do writeFile file ""
+writeDefaultConfigFile :: FilePath -> ConfigFlags -> IO ()
+writeDefaultConfigFile file cfg = 
+    writeFile file $ showFields configWriteFieldDescrs cfg
 
+-- | All config file fields.
 configFieldDescrs :: [FieldDescr ConfigFlags]
 configFieldDescrs =
+    [ 
+    ] ++ configWriteFieldDescrs
+
+-- | The subset of the config file fields that we write out
+-- if the config file is missing.
+configWriteFieldDescrs :: [FieldDescr ConfigFlags]
+configWriteFieldDescrs =
     [  simpleField "compiler"
                 (text . show)   parseCompilerFlavor
                 configCompiler (\c cfg -> cfg { configCompiler = c })
diff --git a/cabal-install/src/Network/Hackage/CabalInstall/Utils.hs b/cabal-install/src/Network/Hackage/CabalInstall/Utils.hs
index 1cbb958..e400559 100644
--- a/cabal-install/src/Network/Hackage/CabalInstall/Utils.hs
+++ b/cabal-install/src/Network/Hackage/CabalInstall/Utils.hs
@@ -10,6 +10,7 @@ import Control.Monad (foldM, guard)
 import Data.Char (isSpace)
 import Data.Maybe (listToMaybe)
 import System.IO.Error (isDoesNotExistError)
+import Text.PrettyPrint.HughesPJ
 
 
 isVerbose cfg = configVerbose cfg >= verbose
@@ -59,3 +60,7 @@ setField _ x s =
 
 lookupFieldDescr :: [FieldDescr a] -> String -> Maybe (FieldDescr a)
 lookupFieldDescr fs n = listToMaybe [f | f@(FieldDescr name _ _) <- fs, name == n]
+
+
+showFields :: [FieldDescr a] -> a -> String
+showFields fs x = render $ vcat [ text name <> text ":" <+> get x | FieldDescr name get _ <- fs]