highlight errors even if real output is to a file

(unless told not to)

exe/Main.idr

@@ -30,7 +30,7 @@ die opts err = do
 private
 runPretty : Options -> Eff Pretty a -> a
 runPretty opts act =
-  let doColor = opts.color && opts.outFile == Stdout
+  let doColor = opts.color && opts.outFile == Console
       hl      = if doColor then highlightSGR else noHighlight
   in
   runPrettyWith Outer opts.flavor hl 2 act
@@ -133,9 +133,9 @@ private
 outputStr : Lazy String -> Eff Compile ()
 outputStr str =
   case !(asksAt OPTS outFile) of
-    None   => pure ()
+    None    => pure ()
-    Stdout => putStr str
+    Console => putStr str
-    File f => do
+    File f  => do
       res <- withFile f WriteTruncate pure $ \h => fPutStr h str
       rethrow $ mapFst (WriteError f) res
 
@@ -221,7 +221,9 @@ main = do
   (_, opts, files) <- options
   case !(runCompile opts !newState $ traverse_ processFile files) of
     Right () => pure ()
-    Left  e  => die (Opts opts.width) $ runPretty opts $ prettyError e
+    Left  e  => die (Opts opts.width) $
+                runPretty ({outFile := Console} opts) $
+                prettyError e
 
 
 -----------------------------------

exe/Options.idr

@@ -11,7 +11,7 @@ import Derive.Prelude
 %language ElabReflection
 
 public export
-data OutFile = File String | Stdout | None
+data OutFile = File String | Console | None
 %name OutFile f
 %runElab derive "OutFile" [Eq, Ord, Show]
 
@@ -44,7 +44,7 @@ export
 defaultOpts : IO Options
 defaultOpts = pure $ MkOpts {
   color   = True,
-  outFile = Stdout,
+  outFile = Console,
   until   = Nothing,
   flavor  = Unicode,
   width   = cast !getTermCols,
@@ -61,7 +61,7 @@ data OptAction = ShowHelp HelpType | Err String | Ok (Options -> Options)
 private
 toOutFile : String -> OptAction
 toOutFile ""  = Ok {outFile := None}
-toOutFile "-" = Ok {outFile := Stdout}
+toOutFile "-" = Ok {outFile := Console}
 toOutFile f   = Ok {outFile := File f}
 
 private