Add --version flag

Author: amaebel

haskell-debugger.cabal

@@ -104,7 +104,9 @@ executable hdb
                       Development.Debug.Adapter.Exit,
                       Development.Debug.Adapter.Handles,
                       Development.Debug.Adapter,
-                      Development.Debug.Interactive
+                      Development.Debug.Interactive,
+                      Paths_haskell_debugger
+    autogen-modules:  Paths_haskell_debugger
     build-depends:
         base, ghc,
         exceptions, aeson, bytestring,

hdb/Main.hs

@@ -3,6 +3,7 @@ module Main where
 
 import System.Environment
 import Data.Maybe
+import Data.Version
 import Text.Read
 
 import DAP
@@ -27,6 +28,8 @@ import GHC.IO.Handle.FD
 import Options.Applicative hiding (command)
 import qualified Options.Applicative
 
+import qualified Paths_haskell_debugger as P
+
 -- | The options `hdb` is invoked in the command line with
 data HdbOptions
   -- | @server --port <port>@
@@ -90,9 +93,13 @@ hdbOptionsParser = hsubparser
   )
   <|> cliParser  -- Default to CLI mode if no subcommand
 
+-- | Parser for --version flag
+versioner :: Parser (a -> a)
+versioner = simpleVersioner $ "Haskell Debugger, version " ++ showVersion P.version
+
 -- | Main parser info
 hdbParserInfo :: ParserInfo HdbOptions
-hdbParserInfo = info (hdbOptionsParser <**> helper)
+hdbParserInfo = info (hdbOptionsParser <**> versioner <**> helper)
   ( fullDesc
  <> header "Haskell debugger supporting both CLI and DAP modes" )