On branch optparse-applicative

Changes to be committed:

      modified:   diddohs.hs
        Added: option parser basics

1 files changed, 19 insertions, 7 deletions

diff --git a/diddohs.hs b/diddohs.hs
index 7ee35cd..6baa5e9 100644
--- a/diddohs.hs
+++ b/diddohs.hs
@@ -3,7 +3,9 @@ import Data.DateTime( parseDateTime, startOfTime, diffSeconds, formatDateTime )
 import Data.List( zip4, zipWith4, transpose )
 import Data.List.Split( splitOn )
 import Data.Maybe( fromJust, fromMaybe )
+import Data.Monoid( mempty )
 import Data.Time.Clock( secondsToDiffTime )
+import Options.Applicative( execParser, info, strOption, long )
 import System.Environment( getArgs )
 import Text.Printf( printf )
 
@@ -24,17 +26,27 @@ data DiddoEntry = DiddoEntry {  start :: String
 instance Show DiddoEntry where
   show (DiddoEntry start finish delta entry) = printf "%s;%s;%s;%s" start finish (show delta) entry
 
-main :: IO ()
-main = do
-  logfile_name : timestring_format : _ <- getArgs
-  logfile_lines_split <- map (splitOn ";") . lines <$> readFile logfile_name
+data DiddoOpts = DiddoOpts
+  { inDateFmt :: String
+  , inFile :: String
+  }
 
-  let [timestrings_finish
+mainWithOpts :: DiddoOpts -> IO ()
+mainWithOpts opts = do
+  [timestrings_finish
         , entries
-        ]                  = transpose logfile_lines_split
-      utcTimes_finish      = map (fromMaybe (error "Input data broken.") . parseDateTime timestring_format) timestrings_finish
+        ]                  <- transpose . map (splitOn ";") . lines <$> readFile (inFile opts)
+  let utcTimes_finish      = map (fromMaybe (error "Input data broken.") . parseDateTime (inDateFmt opts)) timestrings_finish
       entry_deltas_HMMSS   = zipWith (\x y -> secondsToHMS $ diffSeconds x y) utcTimes_finish (startOfTime : init utcTimes_finish)
       diddos_summarized    = zipWith4 DiddoEntry ("" : init timestrings_finish) timestrings_finish entry_deltas_HMMSS entries
 
   mapM_ print diddos_summarized
 
+main :: IO ()
+main = execParser opts >>= mainWithOpts
+  where
+    opts = info parser mempty
+    parser = DiddoOpts
+      <$> strOption ( long "indateform" )
+      <*> strOption ( long "infile" )
+