Merge pull request #6590 from dotty-staging/fix-3683

 Fix #3683: print x.type for singleton types

Author: odersky

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

@@ -147,7 +147,7 @@ class PlainPrinter(_ctx: Context) extends Printer {
       case tp: TypeParamRef =>
         ParamRefNameString(tp) ~ lambdaHash(tp.binder)
       case tp: SingletonType =>
-        toTextLocal(tp.underlying) ~ "(" ~ toTextRef(tp) ~ ")"
+        toTextSingleton(tp)
       case AppliedType(tycon, args) =>
         (toTextLocal(tycon) ~ "[" ~ argsText(args) ~ "]").close
       case tp: RefinedType =>
@@ -226,6 +226,9 @@ class PlainPrinter(_ctx: Context) extends Printer {
     }
   }.close
 
+  def toTextSingleton(tp: SingletonType): Text =
+    toTextLocal(tp.underlying) ~ "(" ~ toTextRef(tp) ~ ")"
+
   protected def paramsText(tp: LambdaType): Text = {
     def paramText(name: Name, tp: Type) = toText(name) ~ toTextRHS(tp)
     Text((tp.paramNames, tp.paramInfos).zipped.map(paramText), ", ")

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

@@ -7,28 +7,33 @@ import dotty.tools.dotc.core.Flags._
 import dotty.tools.dotc.core.NameOps._
 import dotty.tools.dotc.core.Names.Name
 import dotty.tools.dotc.core.Symbols._
-import dotty.tools.dotc.core.Types.ExprType
+import dotty.tools.dotc.core.Types._
 import dotty.tools.dotc.printing.Texts._
 
 
 class ReplPrinter(_ctx: Context) extends DecompilerPrinter(_ctx) {
 
+  val debugPrint = _ctx.settings.YprintDebug.value
+
   override def nameString(name: Name): String =
     if (name.isReplAssignName) name.decode.toString.takeWhile(_ != '$')
     else super.nameString(name)
 
   override protected def exprToText(tp: ExprType): Text =
-    ": " ~ toText(tp.resType)
+    if (debugPrint) super.exprToText(tp)
+    else ": " ~ toText(tp.resType)
 
   override def toText(sym: Symbol): Text =
     if (sym.name.isReplAssignName) nameString(sym.name)
+    else if (debugPrint) super.toText(sym)
     else keyString(sym) ~~ nameString(sym.name.stripModuleClassSuffix)
 
   override def toText(const: Constant): Text =
-    if (const.tag == Constants.StringTag) Str('"' + const.value.toString + '"')
+    if (debugPrint) super.toText(const)
+    else if (const.tag == Constants.StringTag) Str('"' + const.value.toString + '"')
     else Str(const.value.toString)
 
-  override def dclText(sym: Symbol): Text = {
+  override def dclText(sym: Symbol): Text = if (debugPrint) super.dclText(sym) else {
     ("lazy": Text).provided(sym.is(Lazy)) ~~
     toText(sym) ~ {
       if (sym.is(Method)) toText(sym.info)
@@ -38,6 +43,15 @@ class ReplPrinter(_ctx: Context) extends DecompilerPrinter(_ctx) {
     }
   }
 
+  override def toTextSingleton(tp: SingletonType): Text =
+    if (debugPrint)
+      super.toTextSingleton(tp)
+    else
+      tp match {
+        case ConstantType(const) => toText(const)
+        case _                   => toTextRef(tp) ~ ".type"
+      }
+
   // We don't want the colors coming from RefinedPrinter as the REPL uses its
   // own syntax coloring mechanism.
   override def coloredStr(text: String, color: String): String = text

compiler/test-resources/repl/defs

@@ -7,7 +7,7 @@ def baz(): Int
 scala> def qux(): Int = 2
 def qux(): Int
 scala> def id(x: 4): 4 = x
-def id(x: Int(4)): Int(4)
+def id(x: 4): 4
 scala> id(4)
 val res0: Int = 4
 scala> def f given Int = 1

compiler/test-resources/repl/i5218

@@ -3,5 +3,4 @@ val tuple: (Int, String, Long) = (1,2,3)
 scala> 0.0 *: tuple
 val res0: (Double, Int, String, Long) = (0.0,1,2,3)
 scala> tuple ++ tuple
-val res1: Int *: String *: Long *:
-  scala.Tuple.Concat[Unit, (Int, String, Long)(tuple)] = (1,2,3,1,2,3)
+val res1: Int *: String *: Long *: scala.Tuple.Concat[Unit, tuple.type] = (1,2,3,1,2,3)

compiler/test-resources/type-printer/defs

@@ -7,4 +7,4 @@ def baz[A](a: A): A
 scala> def qux[A](a: A): a.type = a
 def qux[A](a: A): a.type
 scala> def singleton: 1 = 1
-def singleton: Int(1)
+def singleton: 1

compiler/test/dotty/tools/repl/ReplCompilerTests.scala

@@ -10,7 +10,7 @@ class ReplCompilerTests extends ReplTest {
 
   @Test def compileSingle = fromInitialState { implicit state =>
     run("def foo: 1 = 1")
-    assertEquals("def foo: Int(1)", storedOutput().trim)
+    assertEquals("def foo: 1", storedOutput().trim)
   }
 
   @Test def compileTwo =
@@ -165,4 +165,14 @@ class ReplCompilerTests extends ReplTest {
       run("IntOrd")
       assertTrue(storedOutput().startsWith("val res0: IntOrd.type ="))
     }
+
+  @Test def testSingletonPrint = fromInitialState { implicit state =>
+    run("""val a = "hello"; val x: a.type = a""")
+    assertEquals("val a: String = hello\nval x: a.type = hello", storedOutput().trim)
+  }
+
+  @Test def i6574 = fromInitialState { implicit state =>
+    run("val a: 1 | 0 = 1")
+    assertEquals("val a: 1 | 0 = 1", storedOutput().trim)
+  }
 }