Print a space between a symbolic operator and a colon.

This affects both RefinedPrinter and ShowSougrceCode. Another example of the tax we pay
for maintaining both.

It required Chars to be moved to scala.tasty.

Author: odersky

compiler/src/dotty/tools/dotc/core/NameOps.scala

@@ -4,7 +4,7 @@ package core
 import java.security.MessageDigest
 import scala.io.Codec
 import Names._, StdNames._, Contexts._, Symbols._, Flags._, NameKinds._, Types._
-import util.Chars
+import scala.tasty.util.Chars
 import Chars.isOperatorPart
 import Definitions._
 

compiler/src/dotty/tools/dotc/core/Names.scala

@@ -7,7 +7,7 @@ import util.NameTransformer
 import printing.{Showable, Texts, Printer}
 import Texts.Text
 import StdNames.str
-import util.Chars.isIdentifierStart
+import scala.tasty.util.Chars.isIdentifierStart
 import collection.immutable
 import config.Config
 import java.util.HashMap

compiler/src/dotty/tools/dotc/parsing/CharArrayReader.scala

@@ -2,7 +2,7 @@ package dotty.tools
 package dotc
 package parsing
 
-import util.Chars._
+import scala.tasty.util.Chars._
 
 abstract class CharArrayReader { self =>
 

compiler/src/dotty/tools/dotc/parsing/JavaScanners.scala

@@ -7,7 +7,7 @@ import Scanners._
 import util.SourceFile
 import JavaTokens._
 import scala.annotation.{ switch, tailrec }
-import util.Chars._
+import scala.tasty.util.Chars._
 
 object JavaScanners {
 

compiler/src/dotty/tools/dotc/parsing/Scanners.scala

@@ -6,7 +6,7 @@ import core.Names._, core.Contexts._, core.Decorators._, util.Positions._
 import core.StdNames._, core.Comments._
 import util.SourceFile
 import java.lang.Character.isDigit
-import util.Chars._
+import scala.tasty.util.Chars._
 import util.NameTransformer.avoidIllegalChars
 import Tokens._
 import scala.annotation.{ switch, tailrec }

compiler/src/dotty/tools/dotc/parsing/package.scala

@@ -1,6 +1,6 @@
 package dotty.tools.dotc
 
-import util.Chars._
+import scala.tasty.util.Chars._
 import core.Names.Name
 import core.StdNames.nme
 import core.NameOps._

compiler/src/dotty/tools/dotc/parsing/xml/MarkupParserCommon.scala

@@ -10,7 +10,7 @@ package parsing
 package xml
 
 import Utility._
-import util.Chars.SU
+import scala.tasty.util.Chars.SU
 
 
 

compiler/src/dotty/tools/dotc/parsing/xml/MarkupParsers.scala

@@ -6,7 +6,7 @@ package xml
 import scala.collection.mutable
 import mutable.{ Buffer, ArrayBuffer, ListBuffer }
 import scala.util.control.ControlThrowable
-import util.Chars.SU
+import scala.tasty.util.Chars.SU
 import Parsers._
 import util.Positions._
 import core._

compiler/src/dotty/tools/dotc/parsing/xml/Utility.scala

@@ -12,7 +12,7 @@ import scala.collection.mutable
  * @author Burak Emir
  */
 object Utility {
-  import util.Chars.SU
+  import scala.tasty.util.Chars.SU
 
   private val unescMap = Map(
     "lt"    -> '<',

compiler/src/dotty/tools/dotc/printing/RefinedPrinter.scala

@@ -19,6 +19,7 @@ import typer.ProtoTypes._
 import Trees._
 import TypeApplications._
 import Decorators._
+import scala.tasty.util.Chars.isOperatorPart
 import transform.TypeUtils._
 
 import language.implicitConversions
@@ -345,7 +346,11 @@ class RefinedPrinter(_ctx: Context) extends PlainPrinter(_ctx) {
           }
         }
       case Typed(expr, tpt) =>
-        changePrec(InfixPrec) { toText(expr) ~ ": " ~ toText(tpt) }
+        changePrec(InfixPrec) {
+          val exprText = toText(expr)
+          val line = exprText.lastLine
+          val colon = if (!line.isEmpty && isOperatorPart(line.last)) " :" else ":"
+          exprText ~ colon ~ toText(tpt) }
       case NamedArg(name, arg) =>
         toText(name) ~ " = " ~ toText(arg)
       case Assign(lhs, rhs) =>