Use cmdargs for command line parsing.

Author: jkozlowski

.gitignore

@@ -1,3 +1,7 @@
 .idea
 dist/
+.dist-buildwrapper/
+cabal-dev/
+.settings/
+.project
 

Setup.hs

@@ -0,0 +1,2 @@
+import Distribution.Simple
+main = defaultMain

diffr.cabal

@@ -1,19 +1,19 @@
-Name:               diffr
-Version:            0.0
-Description:        Intelligent diff/patch tool that knows how to copy and move, has an 'r' at the end of its name.
-License:            GPL-3
-License-file:       LICENCE
-Author:             Amaury Couste, Jakub Kozlowski, William Martin
-Maintainer:
-Build-Type:         Simple
-Cabal-Version:      >=1.2
+name:               diffr
+version:            0.1
+description:        Intelligent diff/patch tool that knows how to copy and move, has an 'r' at the end of its name.
+license:            GPL-3
+license-file:       LICENCE
+author:             Amaury Couste, Jakub Kozlowski, William Martin
+maintainer:
+build-type:         Simple
+cabal-version:      >=1.2
 
-Executable diffr
-  Main-is:          src/diffr/diff/Main.hs
-  Build-Depends:    base >= 4
-  ghc-options: -Wall
-
-Executable patchr
-  Main-is:          src/diffr/patch/Main.hs
-  Build-Depends:    base >= 4
-  ghc-options: -Wall
+executable diffr
+  hs-source-dirs:   src
+  main-is:          Diffr/Main.hs
+  build-Depends:    
+                    base >= 4,
+                    cmdargs > 0.10
+  ghc-options:      -Wall
+  other-modules:    Diffr.Util
+                      

src/diffr/patch/Main.hs renamed to src/Diffr/Main.hs

@@ -1,8 +1,9 @@
+{-# LANGUAGE DeriveDataTypeable, RecordWildCards #-}
 {- |
  Module      :  Main
- Description :  Main entry point for patchr.
+ Description :  Main entry point for diffr.
  Since       :  0.1
- Authors     :  William Martin
+ Authors     :  William Martin, Jakub Kozlowski
  License     :  This file is part of diffr-h.
 
  diffr-h is free software: you can redistribute it and/or modify
@@ -18,12 +19,15 @@
  along with diffr-h.  If not, see <http://www.gnu.org/licenses/>.
 -}
 
-module Main where
+module Main(main) where
 
-import System.Environment
+import System.Environment ( getArgs, withArgs )
+import qualified System.Console.CmdArgs as CM 
+import qualified Diffr.Util as DU
 
--- | 'main' runs the main program
 main :: IO ()
-main = print usage
-
-usage = "patchr says hello"
+main = do
+    args <- getArgs
+    -- If the user did not specify any arguments, pretend as "--help" was given
+    opts <- (if null args then withArgs ["--help"] else id) $ CM.cmdArgsRun DU.diffrModes
+    print opts

src/Diffr/Util.hs

@@ -0,0 +1,99 @@
+{-# LANGUAGE DeriveDataTypeable #-}
+{- |
+ Module      :  Diffr.Util
+ Description :  Utility functions and configuration options
+ Since       :  0.1
+ Authors     :  William Martin, Jakub Kozlowski
+ License     :  This file is part of diffr-h.
+
+ diffr-h is free software: you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation, either version 3 of the License, or
+ (at your option) any later version.
+
+ diffr-h is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ GNU General Public License for more details.
+ You should have received a copy of the GNU General Public License
+ along with diffr-h.  If not, see <http://www.gnu.org/licenses/>.
+-}
+module Diffr.Util (
+      DConfig(..)
+    , diffrModes 
+) where
+
+import System.Console.CmdArgs
+
+{-| Static values -}
+_PROGRAM_NAME, _PROGRAM_VERSION, 
+ _PROGRAM_INFO, _PROGRAM_ABOUT, _COPYRIGHT :: String
+_PROGRAM_NAME = "diffr"
+_PROGRAM_VERSION = "0.1"
+_PROGRAM_INFO = _PROGRAM_NAME ++ " version " ++ _PROGRAM_VERSION
+_PROGRAM_ABOUT = unwords [
+      "An intelligent diff/patch tool"
+    , "that knows how to copy and move,"
+    , "has an 'r' at the end of its name"
+    , "and is written in Haskell."]
+_COPYRIGHT = "(C) diffr 2013"
+
+------------------------------------------------
+
+{-| Configuration for running diffr's commands -}
+data DConfig =
+
+    -- | Configuration for running diff command 
+    Diff  { -- | Path to the 'base' file we will diff against 
+            baseFile     :: FilePath
+  
+            -- | Path to the 'new' file we will compare to 'base' file 
+          , newFile    :: FilePath  
+         
+            -- | Path to the output file where to write the diff file
+          , dOutFile    :: Maybe FilePath
+          }
+        
+    -- | Configuration for running patch command       
+  | Patch { -- | Path to the 'original' file we will apply patch to
+            originalFile :: FilePath
+          
+            -- | Path to the 'patch' file we will apply to 'originalFile'
+          , patchFile  :: FilePath
+          
+            -- | Path to the output file where to write the patched file
+          , pOutFile    :: Maybe FilePath
+          } deriving (Show, Data, Typeable)
+
+{-| Annotate the 'Diff' configuration -}
+diff :: DConfig
+diff = Diff
+    { baseFile  = def &= argPos 0 
+                      &= typ "BASEFILE"    
+    , newFile   = def &= argPos 1 
+                      &= typ "NEWFILE"     
+    , dOutFile  = def &= help "path to the output file"                                      
+                      &= name "output-file" &= typFile
+    }
+                
+{-| Annotate the 'Patch' configuration -}
+patch :: DConfig
+patch = Patch
+    { originalFile  = def &= argPos 0 
+                          &= typ "ORIGINALFILE"              
+    , patchFile     = def &= argPos 1
+                          &= typ "PATCHFILE"        
+    , pOutFile      = def &= help "Path to the output file where to write the patched file"  
+                          &= name "output-file"   
+                          &= typFile
+    }
+
+{-| Available commands -}
+diffrModes :: Mode (CmdArgs DConfig)
+diffrModes = cmdArgsMode $ modes [diff, patch]
+    &= versionArg [explicit, name "version", name "v", summary _PROGRAM_INFO]
+    &= summary (_PROGRAM_INFO ++ ", " ++ _COPYRIGHT)
+    &= help _PROGRAM_ABOUT
+    &= helpArg [explicit, name "help", name "h"]
+    &= program _PROGRAM_NAME
+