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Scala example source code file (t2913.scala)

This example Scala source code file (t2913.scala) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Java - Scala tags/keywords

a, a, array, atoricha, foo, int, int, richa, string, string, t,string, t,t2, t,t2, without

The Scala t2913.scala source code

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 Test {

  implicit def AToRichA(a: A) = 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"`.
                  // None of these po
}

// 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) = 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]) {
    val fn = (a : Int, str : String) => "a: " + a + ", str: " + str
    implicit def fx[T](f : (T,String) => String) = (x:T) => f(x,null)
    println(fn(1))
    ()  
  }
}

Other Scala examples (source code examples)

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