Color REPL under -Dscala.color

We already use -Dscala.color when using -Ytyper-debug

This tries to reuse the colors chosen from the debug flag:

* Bold blue for vals (e.g. "res0")
* Bold green for types (e.g. "Int")
* Magenta for the shell prompt (e.g. "scala>")

3 files changed, 19 insertions, 2 deletions

diff --git a/src/repl/scala/tools/nsc/interpreter/ILoop.scala b/src/repl/scala/tools/nsc/interpreter/ILoop.scala
index 50c89f7442..cfc4e5a5c8 100644
--- a/src/repl/scala/tools/nsc/interpreter/ILoop.scala
+++ b/src/repl/scala/tools/nsc/interpreter/ILoop.scala
@@ -445,8 +445,14 @@ class ILoop(in0: Option[BufferedReader], protected val out: JPrintWriter)
   }
 
   private def readOneLine() = {
+    import scala.io.AnsiColor.{ MAGENTA, RESET }
     out.flush()
-    in readLine prompt
+    in readLine (
+      if (replProps.colorOk)
+        MAGENTA + prompt + RESET
+      else
+        prompt
+    )
   }
 
   /** The main read-eval-print loop for the repl.  It calls
diff --git a/src/repl/scala/tools/nsc/interpreter/MemberHandlers.scala b/src/repl/scala/tools/nsc/interpreter/MemberHandlers.scala
index a37cdc2ec8..8e624174ed 100644
--- a/src/repl/scala/tools/nsc/interpreter/MemberHandlers.scala
+++ b/src/repl/scala/tools/nsc/interpreter/MemberHandlers.scala
@@ -119,7 +119,15 @@ trait MemberHandlers {
           if (replProps.vids) s"""" + f"@$${System.identityHashCode($path)}%8x" + """"
           else ""
 
-        """ + "%s%s: %s = " + %s""".format(string2code(prettyName), vidString, string2code(req typeOf name), resultString)
+        import scala.io.AnsiColor.{ BOLD, BLUE, GREEN, RESET }
+
+        def color(c: String, s: String) =
+          if (replProps.colorOk) string2code(BOLD) + string2code(c) + s + string2code(RESET)
+          else s
+
+        val nameString = color(BLUE, string2code(prettyName)) + vidString
+        val typeString = color(GREEN, string2code(req typeOf name))
+        s""" + "$nameString: $typeString = " + $resultString"""
       }
     }
   }
diff --git a/src/repl/scala/tools/nsc/interpreter/ReplProps.scala b/src/repl/scala/tools/nsc/interpreter/ReplProps.scala
index 36e6dbbccc..8c4faf7278 100644
--- a/src/repl/scala/tools/nsc/interpreter/ReplProps.scala
+++ b/src/repl/scala/tools/nsc/interpreter/ReplProps.scala
@@ -13,6 +13,9 @@ class ReplProps {
   private def bool(name: String) = BooleanProp.keyExists(name)
   private def int(name: String) = IntProp(name)
 
+  // This property is used in TypeDebugging. Let's recycle it.
+  val colorOk = bool("scala.color")
+
   val info  = bool("scala.repl.info")
   val debug = bool("scala.repl.debug")
   val trace = bool("scala.repl.trace")