Bug in REPL: a class or a trait which has `show()` method cannot be instantiated.

[taisukeoe]

Dotty REPL looks treating show method specially to show the result of an instance creation.

In 0.2.0-RC1, a class or a trait which has show() method cannot be instantiated as follows.
(show without parenthesis or show(msg:String) does compile, but unexpectedly used to show the result of instantiation. However, it doesn't change toString implementation.)

scala> class A 
defined class A
scala> new A() 
val res0: A = A@7ee936b9
scala> class B{def show() = "hello"} 
defined class B
scala> new B() 
-- Error: <console>:8:34 -------------------------------------------------------
8 |      line4$object.$iw.$iw.`res1`.show /*toString()*/ + "\n"
  |      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  |      missing arguments for method show in class B
scala> class C{def show = "hello"} 
defined class C
scala> new C() 
val res2: C = hello
scala> class D{def show(msg:String) = msg} 
defined class D
scala> new D() 
val res3: D = RequestResult$$$Lambda$2438/163387956@1cf3be8e
scala> new D().toString 
val res4: String = "D@3b3354b5"

scala> trait E{def show() = "hello"} 
defined trait E
scala> new E{} 
-- Error: <console>:8:35 -------------------------------------------------------
8 |      line12$object.$iw.$iw.`res6`.show /*toString()*/ + "\n"
  |      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  |      missing arguments for method show in trait E

In 0.1.2-RC1, it behaves similar but a bit different.
A class or a trait which has show with arguments cannot be instantiated as follows.
(show without parenthesis or show() does compile, but unexpectedly used to show the result of instantiation. However, it doesn't change toString implementation.)

scala> class A 
defined class A
scala> new A() 
val res0: A = A@6916f3d3
scala> class B{def show() = "hello"} 
defined class B
scala> new B() 
val res1: B = hello
scala> class C{def show = "hello") 
-- [E039] Syntax Error: <console>:1:26 -----------------------------------------
1 |class C{def show = "hello")
  |                          ^
  |                          ';' expected, but ')' found
scala> class C{def show = "hello"} 
defined class C
scala> new C() 
val res2: C = hello
scala> class D{def show(msg:String) = msg} 
defined class D
scala> new D() 
-- Error: <console>:8:34 -------------------------------------------------------
8 |      line8$object.$iw.$iw.`res3`.show /*toString()*/ + "\n"
  |      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  |missing arguments for method show in class D
  |follow this method with `_' if you want to treat it as a partially applied function
scala> new C().toString 
val res4: String = "C@772abeb"

scala> trait E{def show(msg:String) = msg} 
defined trait E
scala> new E{} 
-- Error: <console>:8:35 -------------------------------------------------------
8 |      line13$object.$iw.$iw.`res5`.show /*toString()*/ + "\n"
  |      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  |missing arguments for method show in trait E
  |follow this method with `_' if you want to treat it as a partially applied function

scala> class F{def show(i:Int) = i} 
defined class F
scala> new F() 
-- Error: <console>:8:35 -------------------------------------------------------
8 |      line15$object.$iw.$iw.`res6`.show /*toString()*/ + "\n"
  |      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  |missing arguments for method show in class F
  |follow this method with `_' if you want to treat it as a partially applied function

[taisukeoe]

Interestingly, anonymous class instantiation works good in both of 0.2.0-RC1 and 0.1.2-RC1, though it might be better to be an AnyRef instead of Object.

In 0.2.0-RC1:

scala> new {def show() = "hello"} 
val res7: Object = $anon$1@171a2ea

In 0.1.2-RC1:

scala> new {def show(msg:String) = msg} 
val res0: Object = $anon$1@ec2bf76