updating to using optparse-applicative

Lib/DecimalTime.hs

@@ -30,6 +30,7 @@ import Types
     DecimalTime (..),
     Seconds (..),
     ValidDecimalTime (..),
+    (><),
     currentDate,
     decimalTime,
     extendedFlag)
@@ -72,7 +73,7 @@ timeOfDayToFraction = Days . (/ secondsInDay) . (\(Seconds s) -> s) . timeOfDayT
 {-# INLINEABLE mkValidDecimalTime #-}
 mkValidDecimalTime :: DecimalTime -> Either String ValidDecimalTime
 mkValidDecimalTime dt@(DecimalTime t)
-  | t >= 0 && t <= 1000 = Right $ ValidDecimalTime dt
+  | t >< 1000 = Right $ ValidDecimalTime dt
   | otherwise = Left "Time must be between 0 and 1000"
 
 -- | Convert fraction of day to decimal time

Lib/Types.hs

@@ -23,13 +23,17 @@ module Types (
   , currentDate
   , Lens
   , Lens''
-  , RunMode(..)
-  , Config(..)
+  , (><)
 ) where
 
 import Data.Time (LocalTime)
 import qualified Control.Lens as L
 
+-- | Infix operator for range checking where lower bound is 0
+infixr 5 ><
+(><) :: Integer -> Integer -> Bool
+(><) x y = x >= 0 && x <= y
+
 -- | Decimal time types
 newtype Seconds = Seconds Double
   deriving (Eq, Ord, Num, Fractional, Real, RealFrac)
@@ -44,13 +48,6 @@ newtype DecimalTime = DecimalTime Integer
 newtype ValidDecimalTime = ValidDecimalTime DecimalTime
   deriving (Show, Eq)
 
-data RunMode = SingleRun | Watch
-
-data Config = Config
-    { extended :: Bool
-    , mode     :: RunMode
-    }
-
 data ClockState = ClockState
   { _extendedFlag :: Bool,
     _decimalTime  :: Maybe ValidDecimalTime,

README.md

@@ -14,19 +14,23 @@ Usage
 You can type -v or --version to see program information or -e to print extended information which is the current date. If you want to leave it running for a realtime decimal clock use the -w option.
 
 ```
-$ cabal run
-Decimal time: 292
-$ 
-```
-or if you have copied the "dclock" executable to a bin directory
+$ cabal run exe:dclock -- -h
+dclock - decimal time clock
 
-```
-$ dclock
-Decimal time: 999
-$ dclock -v
-Decimal time clock that maps your day to 1000 decimal minutes, version 1.0.0 (x86_64-linux)
-$ dclock -e
-Decimal time: 49 (2024-10-30)
+Usage: dclock [(-v|--version) | [-e|--extended] [-w|--watch]]
+
+  Decimal time clock that maps your day to 1000 decimal minutes
+
+Available options:
+  -v,--version             Show version information
+  -e,--extended            Show extended information including date
+  -w,--watch               Watch mode, view as a realtime decimal clock (updates
+                           every second)
+  -h,--help                Show this help text
+$ cabal run
+Decimal time: 25
+$ cabal run exe:dclock -- -e
+Decimal time: 25 (2024-11-05)
 $
 ```
 Building

app/Main.hs

@@ -1,5 +1,4 @@
 {-# LANGUAGE OverloadedStrings #-}
-{-# LANGUAGE LambdaCase #-}
 {-# LANGUAGE RankNTypes #-}
 -----------------------------------------------------------------------------
 -- |
@@ -27,19 +26,54 @@ import Data.Time (ZonedTime, getZonedTime)
 import Control.Monad.IO.Class (liftIO)
 import Control.Concurrent (threadDelay)
 import System.Info (arch, os)
-import System.Environment(getArgs)
 import Data.Function(fix)
+import Options.Applicative
 import qualified Data.Text as T
 import qualified Data.Text.IO as TIO
 import qualified PrettyPrinter as Pretty (formatTime, displaySingleLine)
 import qualified DecimalTime as DT (
       localTimeToDecimal,
       setCurrentDate)
-import Types (
-       ClockState( .. ), 
-       Config(..), 
-       RunMode(SingleRun, 
-       Watch))
+import Types (ClockState( .. ))
+
+data RunMode = SingleRun | Watch
+
+data Config = Config
+    { extended :: Bool
+    , mode     :: RunMode
+    }
+
+data Command
+  = Version
+  | Run Config
+
+-- | Parser for command line arguments
+parser :: Parser Command
+parser = versionCmd <|> runCmd
+  where
+    versionCmd =
+      flag'
+        Version
+        ( long "version"
+            <> short 'v'
+            <> help "Show version information"
+        )
+
+    runCmd =
+      fmap Run $
+        Config
+          <$> switch
+            ( long "extended"
+                <> short 'e'
+                <> help "Show extended information including date"
+            )
+          <*> flag
+            SingleRun
+            Watch
+            ( long "watch"
+                <> short 'w'
+                <> help "Watch mode, view as a realtime decimal clock (updates every second)"
+            )
 
 -- | Get platform information for version string
 createPlatformText :: T.Text
@@ -68,37 +102,37 @@ zonedTime = construct $ do
   zt <- liftIO getZonedTime
   yield zt
 
--- | Process args and run the clock
-runClockProcess :: [String] -> IO ()
-runClockProcess = \case
-    []            -> runWith $ Config False SingleRun
-    ["-e"]        -> runWith $ Config True SingleRun
-    ["-w"]        -> runWith $ Config False Watch
-    ["-w", "-e"]  -> runWith $ Config True Watch
-    ["-e", "-w"]  -> runWith $ Config True Watch
-    ["-v"]        -> displayVersionText
-    ["--version"] -> displayVersionText
-    _             -> displayValidArgs
+main :: IO ()
+main = execParser opts >>= run
   where
-    runWith :: Config -> IO ()
-    runWith config = case mode config of
-      SingleRun -> runClock (extended config) >> TIO.putStrLn ""
-      Watch     -> watchClock (extended config)
+    opts =
+      info
+        (parser <**> helper)
+        ( fullDesc
+            <> progDesc "Decimal time clock that maps your day to 1000 decimal minutes"
+            <> header "dclock - decimal time clock"
+        )
+
+    run :: Command -> IO ()
+    run Version = displayVersionText
+    run (Run config) = runWith config
+      where
+        runWith :: Config -> IO ()
+        runWith config' = case mode config' of
+          SingleRun -> runClock (extended config') >> TIO.putStrLn ""
+          Watch     -> watchClock (extended config')
 
-    runClock :: Bool -> IO ()
-    runClock e = do
-      let state = ClockState e Nothing Nothing
-      runT_ $
-        zonedTime
-          ~> M.mapping (`DT.setCurrentDate` state)
-          ~> M.mapping DT.localTimeToDecimal
-          ~> M.mapping Pretty.formatTime
-          ~> displayTimeText
+        runClock :: Bool -> IO ()
+        runClock e = do
+          let state = ClockState e Nothing Nothing
+          runT_ $
+            zonedTime
+              ~> M.mapping (`DT.setCurrentDate` state)
+              ~> M.mapping DT.localTimeToDecimal
+              ~> M.mapping Pretty.formatTime
+              ~> displayTimeText
 
-    watchClock :: Bool -> IO ()
-    watchClock extended' = 
-      TIO.putStrLn "Press Ctrl-C to exit\n" >>
-      fix (\loop -> runClock extended' >> threadDelay 1000000 >> loop)
-
-main :: IO ()
-main = getArgs >>= runClockProcess
+        watchClock :: Bool -> IO ()
+        watchClock extended' = 
+          TIO.putStrLn "Press Ctrl-C to exit\n" >>
+          fix (\loop -> runClock extended' >> threadDelay 1000000 >> loop)

dclock.cabal

@@ -44,6 +44,7 @@ executable dclock
                       time ^>=1.14,
                       machines ^>= 0.7.2,
                       text ^>= 2.1.1,
+                      optparse-applicative ^>= 0.18.1
     hs-source-dirs:   app
     default-language: Haskell2010