Add color/no-color flag

This resolves anttih#2. Happy Hacktoberfest!

src/PscPane/Action.purs

@@ -53,6 +53,7 @@ type State =
   , screen ∷ Screen
   , box ∷ Box
   , prevPaneState ∷ PaneState
+  , colorize ∷ Boolean
   }
 
 getState ∷ StateT State AffN State
@@ -71,9 +72,9 @@ appN (BuildProject f) = do
   buf ← lift $ spawnAff buildCmd
   liftEff $ f <$> toString UTF8 buf
 appN (DrawPaneState state a) = do
-  { screen, box, cwd } ← getState
+  { screen, box, cwd, colorize } ← getState
   height ← liftEff rows
-  liftEff (setContent box (formatState cwd height state))
+  liftEff (setContent box (formatState colorize cwd height state))
   liftEff (render screen)
   modify (_ { prevPaneState = state })
   pure a

src/PscPane/Main.purs

@@ -22,7 +22,7 @@ import Data.Maybe.First (First(..), runFirst)
 import Data.String (split, trim)
 import Node.Path (FilePath)
 import Node.Process as P
-import Node.Yargs.Applicative (yarg, runY)
+import Node.Yargs.Applicative (flag, yarg, runY)
 import Node.Yargs.Setup (usage, defaultHelp, defaultVersion)
 import PscIde.Command (RebuildResult(RebuildResult))
 import PscPane.Parser (PscResult(PscResult))
@@ -91,8 +91,8 @@ rebuildModule path = do
     toPaneState _ (Just res) = PscError res
     toPaneState path Nothing = ModuleOk path "building project..."
 
-app ∷ String → Array String → EffN Unit
-app buildCmd dirs = void do
+app ∷ String → Array String → Boolean → EffN Unit
+app buildCmd dirs colorize = void do
   cwd ← P.cwd
   let
     screen = mkScreen { smartCSR: true }
@@ -109,7 +109,7 @@ app buildCmd dirs = void do
   runAff fail pure do
     running ← startPscIdeServer cwd $ range 4242 4252
     port ← maybe (throwError (error "Cannot start psc-ide-server")) pure running
-    stateRef ← liftEff $ newRef { screen, box, port, cwd, buildCmd, prevPaneState: InitialBuild }
+    stateRef ← liftEff $ newRef { screen, box, port, cwd, buildCmd, prevPaneState: InitialBuild, colorize }
     let
       runCmd ∷ A.Action Unit → AffN Unit
       runCmd program =
@@ -169,3 +169,5 @@ main = do
       (Just  "Directory to watch for changes (default: \"src\")")
       (Left ["src"])
       true
+    <*> flag "p" ["color"]
+      (Just "Colorize output. On by default. --no-color to turn off.")

src/PscPane/Pretty.purs

@@ -22,17 +22,29 @@ data PaneState
   | ModuleOk FilePath Progress
   | PscError PaneResult
 
-formatState ∷ FilePath → Height → PaneState → String
-formatState _ _ InitialBuild = "Building project..."
-formatState cwd height (PscError res) = pretty cwd height res
-formatState _ _ (ModuleOk path progress) = green "Module OK" <> " " <> path <> " (" <> progress <> ")"
-formatState _ _ BuildSuccess = green "Build successful"
+formatState ∷ Boolean → FilePath → Height → PaneState → String
+formatState _ _ _ InitialBuild = "Building project..."
+formatState colorize cwd height (PscError res) = pretty colorize cwd height res
+formatState colorize _ _ (ModuleOk path progress) = green' colorize "Module OK" <> " " <> path <> " (" <> progress <> ")"
+formatState colorize _ _ BuildSuccess = green' colorize "Build successful"
 
 data PaneResult = Warning RebuildError | Error RebuildError
 
-pretty ∷ FilePath → Height → PaneResult → String
-pretty cwd h (Warning warn) = prettyError' (yellow "Warning") cwd h warn
-pretty cwd h (Error err) = prettyError' (red "Error") cwd h err
+pretty ∷ Boolean → FilePath → Height → PaneResult → String
+pretty colorize cwd h (Warning warn) = prettyError' (yellow' colorize "Warning") cwd h warn
+pretty colorize cwd h (Error err) = prettyError' (red' colorize "Error") cwd h err
+
+yellow' ∷ Boolean → String → String
+yellow' true = yellow
+yellow' fale = id
+
+green' ∷ Boolean → String → String
+green' true = green
+green' fale = id
+
+red' ∷ Boolean → String → String
+red' true = red
+red' fale = id
 
 prettyError' ∷ String → FilePath → Height → RebuildError → String
 prettyError' t cwd h (RebuildError err@{ position }) =