Factor out coloring check to new method Context#useColors

Author: felixmulder

src/dotty/tools/dotc/core/Contexts.scala

@@ -370,6 +370,10 @@ object Contexts {
     /** Is the verbose option set? */
     def verbose: Boolean = base.settings.verbose.value
 
+    /** Should use colors when printing? */
+    def useColors: Boolean =
+      List("auto", "always") contains base.settings.color.value
+
     /** A condensed context containing essential information of this but
      *  no outer contexts except the initial context.
     private var _condensed: CondensedContext = null

src/dotty/tools/dotc/repl/AmmoniteReader.scala

@@ -58,8 +58,7 @@ class AmmoniteReader(val interpreter: Interpreter)(implicit ctx: Context) extend
       allFilters,
       displayTransform = (buffer, cursor) => {
         val coloredBuffer =
-          if (List("auto", "always").contains(ctx.settings.color.value))
-            SyntaxHighlighting(buffer)
+          if (ctx.useColors) SyntaxHighlighting(buffer)
           else buffer
 
         val ansiBuffer = Ansi.Str.parse(coloredBuffer)

src/dotty/tools/dotc/repl/CompilingInterpreter.scala

@@ -406,7 +406,7 @@ class CompilingInterpreter(out: PrintWriter, ictx: Context) extends Compiler wit
     }
 
     /** load and run the code using reflection.
-     *  @return  A pair consisting of the run's result as a string, and
+     *  @return  A pair consisting of the run's result as a `List[String]`, and
      *           a boolean indicating whether the run succeeded without throwing
      *           an exception.
      */
@@ -417,12 +417,11 @@ class CompilingInterpreter(out: PrintWriter, ictx: Context) extends Compiler wit
         interpreterResultObject.getMethod("result")
       try {
         withOutput(new ByteOutputStream) { ps =>
-          val rawRes    = valMethodRes.invoke(interpreterResultObject).toString
-          val res       =
-            if (List("auto", "always").contains(ictx.settings.color.value))
-              new String(SyntaxHighlighting(rawRes).toArray)
+          val rawRes = valMethodRes.invoke(interpreterResultObject).toString
+          val res =
+            if (ictx.useColors) new String(SyntaxHighlighting(rawRes).toArray)
             else rawRes
-          val prints    = ps.toString("utf-8")
+          val prints = ps.toString("utf-8")
           val printList = if (prints != "") prints :: Nil else Nil
 
           if (!delayOutput) out.print(prints)