Add optparse-applicative

app/Main.hs

@@ -4,23 +4,65 @@ import qualified Control.Monad
 import qualified Data.Foldable
 import qualified Haskell.Verify.Examples as HVE
 import NriPrelude
+import Options.Applicative ((<**>))
+import qualified Options.Applicative as OA
 import qualified System.Directory
 import qualified System.Environment
 import System.FilePath.Find ((&&?), (==?))
 import qualified System.FilePath.Find as Find
+import Prelude ((<>))
 import qualified Prelude
 
+data Options = Options
+  { files :: List Prelude.FilePath,
+    showTodos :: ShowTodos
+  }
+  deriving (Show)
+
+data ShowTodos = ShowTodos | HideTodos
+  deriving (Show)
+
+optionsParser :: OA.Parser Options
+optionsParser =
+  map2
+    Options
+    ( OA.many
+        <| OA.strOption
+          ( OA.metavar "FILES"
+              <> OA.help "Specific files to verify"
+          )
+    )
+    ( OA.flag
+        HideTodos
+        ShowTodos
+        ( OA.long "todos"
+            <> OA.short 't'
+            <> OA.help "Show examples that don't have a verified result yet."
+        )
+    )
+
+optionsInfo :: OA.ParserInfo Options
+optionsInfo =
+  OA.info
+    (optionsParser <**> OA.helper)
+    ( OA.fullDesc
+        <> OA.progDesc "Verify that your examples are correct."
+        <> OA.header "haskell-verify-examples"
+    )
+
 main :: Prelude.IO ()
 main = do
   logHandler <- Platform.silentHandler
   handler <- HVE.handler logHandler
   cwd <- System.Directory.getCurrentDirectory
   params <- System.Environment.getArgs
-  files <- case params of
+  options <- OA.execParser optionsInfo
+  let _ = Debug.log "opts" options
+  files' <- case files options of
     [file] -> Prelude.pure [file]
     [] -> Find.find (noRCS &&? noDist) (Find.extension ==? ".hs") cwd
   results <-
-    files
+    files'
       |> List.map
         ( \modulePath -> do
             parsed <- HVE.parse handler modulePath

package.yaml

@@ -24,6 +24,7 @@ executables:
       - haskell-verify-examples
       - hint >= 0.9.0.4 && < 0.10
       - nri-prelude >= 0.1.0.0 && < 0.7
+      - optparse-applicative >= 0.16.1.0 && < 0.17
       - text >= 1.2.3.1 && < 1.3
     main: Main.hs
     source-dirs: app