scala> val i: Int = "foo"
<console>:7: error: type mismatch;
 found   : String("foo")
 required: Int
       val i: Int = "foo"
                    ^

scala> :pa
// Entering paste mode (ctrl-D to finish)

val i: Int = "foo"

// Exiting paste mode, now interpreting.

<console>:7: error: type mismatch;
 found   : String("foo")
 required: Int
       val i: Int = "foo"
                    ^

scala> { val j = 42 ; val i: Int = "foo" + j }
<console>:8: error: type mismatch;
 found   : String
 required: Int
              { val j = 42 ; val i: Int = "foo" + j }
                                                ^