dhall-json: Add --output options (#1304)

As requested in #1303.

dhall-json/dhall-to-json/Main.hs

@@ -14,7 +14,6 @@ import Options.Applicative (Parser, ParserInfo)
 import qualified Control.Exception
 import qualified Data.Aeson
 import qualified Data.Aeson.Encode.Pretty
-import qualified Data.ByteString.Char8
 import qualified Data.ByteString.Lazy
 import qualified Data.Text.IO             as Text.IO
 import qualified Dhall
@@ -33,6 +32,7 @@ data Options
         , conversion                :: Conversion
         , approximateSpecialDoubles :: Bool
         , file                      :: Maybe FilePath
+        , output                    :: Maybe FilePath
         }
     | Version
 
@@ -45,6 +45,7 @@ parseOptions =
         <*> Dhall.JSON.parseConversion
         <*> parseApproximateSpecialDoubles
         <*> optional parseFile
+        <*> optional parseOutput
         )
     <|> parseVersion
   where
@@ -94,6 +95,13 @@ parseOptions =
             <>  Options.metavar "FILE"
             )
 
+    parseOutput =
+        Options.strOption
+            (   Options.long "output"
+            <>  Options.help "Write JSON to a file instead of standard output"
+            <>  Options.metavar "FILE"
+            )
+
 parserInfo :: ParserInfo Options
 parserInfo =
     Options.info
@@ -137,7 +145,12 @@ main = do
 
                 json <- omission <$> explaining (Dhall.JSON.codeToValue conversion specialDoubleMode file text)
 
-                Data.ByteString.Char8.putStrLn $ Data.ByteString.Lazy.toStrict $ encode json
+                let write =
+                        case output of
+                            Nothing -> Data.ByteString.Lazy.putStr
+                            Just file_ -> Data.ByteString.Lazy.writeFile file_
+
+                write (encode json <> "\n")
 
 handle :: IO a -> IO a
 handle = Control.Exception.handle handler

dhall-json/dhall-to-yaml/Main.hs

@@ -29,6 +29,7 @@ parseOptions =
             <*> parseQuoted
             <*> Dhall.JSON.parseConversion
             <*> optional parseFile
+            <*> optional parseOutput
             )
     <|> parseVersion
   where
@@ -52,6 +53,13 @@ parseOptions =
             <>  Options.help "Display version"
             )
 
+    parseOutput =
+        Options.strOption
+            (   Options.long "output"
+            <>  Options.help "Write YAML to a file instead of standard output"
+            <>  Options.metavar "FILE"
+            )
+
 parserInfo :: ParserInfo (Maybe Options)
 parserInfo =
     Options.info
@@ -76,7 +84,12 @@ main = do
                     Nothing   -> Text.IO.getContents
                     Just path -> Text.IO.readFile path
 
-                Data.ByteString.putStr =<< dhallToYaml options file contents
+                let write =
+                        case output of
+                            Nothing -> Data.ByteString.putStr
+                            Just file_ -> Data.ByteString.writeFile file_
+
+                write =<< dhallToYaml options file contents
 
 handle :: IO a -> IO a
 handle = Control.Exception.handle handler

dhall-json/json-to-dhall/Main.hs

@@ -23,6 +23,7 @@ import qualified Data.ByteString.Lazy.Char8                as ByteString
 import qualified Data.Text.IO                              as Text.IO
 import qualified Data.Text.Prettyprint.Doc                 as Pretty
 import qualified Data.Text.Prettyprint.Doc.Render.Terminal as Pretty.Terminal
+import qualified Data.Text.Prettyprint.Doc.Render.Text     as Pretty.Text
 import qualified GHC.IO.Encoding
 import qualified Options.Applicative                       as Options
 import qualified System.Console.ANSI                       as ANSI
@@ -49,6 +50,7 @@ data Options
         { schema     :: Text
         , conversion :: Conversion
         , file       :: Maybe FilePath
+        , output     :: Maybe FilePath
         , ascii      :: Bool
         , plain      :: Bool
         }
@@ -62,6 +64,7 @@ parseOptions =
         <$> parseSchema
         <*> parseConversion
         <*> optional parseFile
+        <*> optional parseOutput
         <*> parseASCII
         <*> parsePlain
         )
@@ -88,6 +91,13 @@ parseOptions =
             <>  Options.metavar "FILE"
             )
 
+    parseOutput =
+        Options.strOption
+            (   Options.long "output"
+            <>  Options.help "Write Dhall expression to a file instead of standard output"
+            <>  Options.metavar "FILE"
+            )
+
     parseASCII =
         Options.switch
             (   Options.long "ascii"
@@ -138,16 +148,24 @@ main = do
 
                 let stream = Pretty.layoutSmart Dhall.Pretty.layoutOpts document
 
-                supportsANSI <- ANSI.hSupportsANSI IO.stdout
+                case output of
+                    Nothing -> do
+                        supportsANSI <- ANSI.hSupportsANSI IO.stdout
 
-                let ansiStream =
-                        if supportsANSI && not plain
-                        then fmap Dhall.Pretty.annToAnsiStyle stream
-                        else Pretty.unAnnotateS stream
+                        let ansiStream =
+                                if supportsANSI && not plain
+                                then fmap Dhall.Pretty.annToAnsiStyle stream
+                                else Pretty.unAnnotateS stream
 
-                Pretty.Terminal.renderIO IO.stdout ansiStream
+                        Pretty.Terminal.renderIO IO.stdout ansiStream
 
-                Text.IO.putStrLn ""
+                        Text.IO.putStrLn ""
+
+                    Just file_ ->
+                        IO.withFile file_ IO.WriteMode $ \h -> do
+                            Pretty.Text.renderIO h stream
+
+                            Text.IO.hPutStrLn h ""
 
 handle :: IO a -> IO a
 handle = Control.Exception.handle handler

dhall-json/src/Dhall/Yaml.hs

@@ -38,6 +38,7 @@ data Options = Options
     , quoted     :: Bool
     , conversion :: Conversion
     , file       :: Maybe FilePath
+    , output     :: Maybe FilePath
     }
 
 defaultOptions :: Options
@@ -48,6 +49,7 @@ defaultOptions =
           , quoted = False
           , conversion = NoConversion
           , file = Nothing
+          , output = Nothing
           }
 
 parseDocuments :: Parser Bool

dhall-json/yaml-to-dhall/Main.hs

@@ -23,6 +23,7 @@ import qualified Data.ByteString.Char8                     as BSL8
 import qualified Data.Text.IO                              as Text.IO
 import qualified Data.Text.Prettyprint.Doc                 as Pretty
 import qualified Data.Text.Prettyprint.Doc.Render.Terminal as Pretty.Terminal
+import qualified Data.Text.Prettyprint.Doc.Render.Text     as Pretty.Text
 import qualified Dhall.Pretty
 import qualified GHC.IO.Encoding
 import qualified Options.Applicative                       as Options
@@ -40,6 +41,7 @@ data CommandOptions
         { schema     :: Text
         , conversion :: Conversion
         , file       :: Maybe FilePath
+        , output     :: Maybe FilePath
         , ascii      :: Bool
         , plain      :: Bool
         }
@@ -61,6 +63,7 @@ parseOptions =
         <$> parseSchema
         <*> parseConversion
         <*> optional parseFile
+        <*> optional parseOutput
         <*> parseASCII
         <*> parsePlain
         )
@@ -87,6 +90,13 @@ parseOptions =
             <>  Options.metavar "FILE"
             )
 
+    parseOutput =
+        Options.strOption
+            (   Options.long "output"
+            <>  Options.help "Write Dhall expression to a file instead of standard output"
+            <>  Options.metavar "FILE"
+            )
+
     parseASCII =
         Options.switch
             (   Options.long "ascii"
@@ -129,17 +139,24 @@ main = do
 
                 let stream = Pretty.layoutSmart Dhall.Pretty.layoutOpts document
 
-                supportsANSI <- ANSI.hSupportsANSI IO.stdout
+                case output of
+                    Nothing -> do
+                        supportsANSI <- ANSI.hSupportsANSI IO.stdout
 
-                let ansiStream =
-                        if supportsANSI && not plain
-                        then fmap Dhall.Pretty.annToAnsiStyle stream
-                        else Pretty.unAnnotateS stream
+                        let ansiStream =
+                                if supportsANSI && not plain
+                                then fmap Dhall.Pretty.annToAnsiStyle stream
+                                else Pretty.unAnnotateS stream
 
-                Pretty.Terminal.renderIO IO.stdout ansiStream
+                        Pretty.Terminal.renderIO IO.stdout ansiStream
 
-                Text.IO.putStrLn ""
+                        Text.IO.putStrLn ""
 
+                    Just file_ ->
+                        IO.withFile file_ IO.WriteMode $ \h -> do
+                            Pretty.Text.renderIO h stream
+
+                            Text.IO.hPutStrLn h ""
 
 handle :: IO a -> IO a
 handle = Control.Exception.handle handler