1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
|
class A {
def foo(a: Int) = 0
}
class RichA {
def foo(a: String) = 0
def foo(a: String, b: String) = 0
def foo() = 0
}
object TestNoAutoTupling {
import language.noAutoTupling // try with on and off
implicit def AToRichA(a: A): RichA = new RichA
val a = new A
a.foo()
a.foo(1)
a.foo("") // Without implicits, a type error regarding invalid argument types is generated at `""`. This is
// the same position as an argument, so the 'second try' typing with an Implicit View is tried,
// and AToRichA(a).foo("") is found.
//
// My reading of the spec "7.3 Views" is that `a.foo` denotes a member of `a`, so the view should
// not be triggered.
//
// But perhaps the implementation was changed to solve See https://lampsvn.epfl.ch/trac/scala/ticket/1756
a.foo("a", "b") // Without implicits, a type error regarding invalid arity is generated at `foo(<error>"", "")`.
// Typers#tryTypedApply:3274 only checks if the error is as the same position as `foo`, `"a"`, or `"b"`.
}
// t0851 is essentially the same:
object test1 {
case class Foo[T,T2](f : (T,T2) => String) extends (((T,T2)) => String){
def apply(t : T) = (s:T2) => f(t,s)
def apply(p : (T,T2)) = f(p._1,p._2)
}
implicit def g[T](f : (T,String) => String): test1.Foo[T,String] = Foo(f)
def main(args : Array[String]) : Unit = {
val f = (x:Int,s:String) => s + x
println(f(1))
()
}
}
object Main {
def main(args : Array[String]): Unit = {
val fn = (a : Int, str : String) => "a: " + a + ", str: " + str
implicit def fx[T](f : (T,String) => String): T => String = (x:T) => f(x,null)
println(fn(1))
()
}
}
object TestWithAutoTupling {
implicit def AToRichA(a: A): RichA = new RichA
val a = new A
a.foo()
a.foo(1)
a.foo("") // Without implicits, a type error regarding invalid argument types is generated at `""`. This is
// the same position as an argument, so the 'second try' typing with an Implicit View is tried,
// and AToRichA(a).foo("") is found.
//
// My reading of the spec "7.3 Views" is that `a.foo` denotes a member of `a`, so the view should
// not be triggered.
//
// But perhaps the implementation was changed to solve See https://lampsvn.epfl.ch/trac/scala/ticket/1756
a.foo("a", "b") // Without implicits, a type error regarding invalid arity is generated at `foo(<error>"", "")`.
// Typers#tryTypedApply:3274 only checks if the error is as the same position as `foo`, `"a"`, or `"b"`.
}
|
