Why does Scala evaluate the argument for a call-by-name parameter if the method is infix and right-associative?

Question

As I understood call-by-name parameters of a method, the corresponding argument expression will not be evaluated when passing it to the method, but only when (a

Answer 1

By-name arguments are evaluated whenever they are mentioned. The spec says that right-associative operator method calls are evaluated like this:

a op_: b

desugars to:

{ val someFreshName = a; b.op_:(someFreshName) }
//                   ↑↑↑
// Eval happens here ↑↑↑