Lazy evaluation of closures during object construction

gistfile1.scala

scala> def test = { println("Evaluating"); "test" }                                                                 
test: java.lang.String

scala> case class TestClass(s: String) { override def toString = "overrided so the REPL doesn't coerse evaluation of s" }
defined class TestClass

scala> val t = TestClass(test)                                                                                      
Evaluating
t: TestClass = overrided so the REPL doesn't coerse evaluation of s

scala> // Construction of TestClass has evaluated s attribute

scala> trait TestTrait { def s: String }                                                                            
defined trait TestTrait

scala> val t = new TestTrait { lazy val s = test }              
t: java.lang.Object with TestTrait = $anon$1@4b3ca972

scala> // Construction of TestTrait instance has not evaluated s attribute

scala> t.s
Evaluating
res1: String = test

scala> t.s
res2: String = test

scala> // Second call for s attribute doesn't reevaluate

scala>