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class A {
// First three compile.
def f1(x: Either[Int, String]) = x.right map (y => y)
def f2(x: Either[Int, String]) = for (y <- x.right) yield y
def f3(x: Either[Int, (String, Int)]) = x.right map { case (y1, y2) => (y1, y2) }
// Last one fails.
def f4(x: Either[Int, (String, Int)]) = for ((y1, y2) <- x.right) yield ((y1, y2))
/**
./a.scala:5: error: constructor cannot be instantiated to expected type;
found : (T1, T2)
required: Either[Nothing,(String, Int)]
def f4(x: Either[Int, (String, Int)]) = for ((y1, y2) <- x.right) yield ((y1, y2))
^
./a.scala:5: error: not found: value y1
def f4(x: Either[Int, (String, Int)]) = for ((y1, y2) <- x.right) yield ((y1, y2))
^
./a.scala:5: error: not found: value y2
def f4(x: Either[Int, (String, Int)]) = for ((y1, y2) <- x.right) yield ((y1, y2))
^
three errors found
**/
def f5(x: Either[Int, String]) = for ((y1, y2: String) <- x.right) yield ((y1, y2))
def f6(x: Either[Int, String]) = for ((y1, y2: Any) <- x.right) yield ((y1, y2))
def f7(x: Either[Int, (String, Int)]) = for (y1 @ Tuple1(y2) <- x.right) yield ((y1, y2))
def f8(x: Either[Int, (String, Int)]) = for ((y1, y2, y3) <- x.right) yield ((y1, y2))
}
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