From 48f6cdda26d23c563511caaf6842691b2cf5d23e Mon Sep 17 00:00:00 2001 From: Adriaan Moors Date: Tue, 11 Feb 2014 11:31:01 -0800 Subject: Revert "SI-1786 incorporate defined bounds in inference" Have to revert because the stricter bounds that it inferred break e.g., slick. (Backstop for that added as pos/t1786-counter.scala, as minimized by Jason) Worse, the fix was compilation order-dependent. There's a less invasive fix (SI-6169) that could be generalized in `sharpenQuantifierBounds` (used in `skolemizeExistential`), but I'd rather not mess with existentials at this point. This reverts commit e28c3edda4dd405ed382227d2a688b799bf33c72. Conflicts: src/compiler/scala/tools/nsc/typechecker/Typers.scala test/files/pos/t1786.scala --- test/pending/pos/t1786.scala | 27 +++++++++++++++++++++++++ test/pending/pos/t5459.scala | 48 ++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 75 insertions(+) create mode 100644 test/pending/pos/t1786.scala create mode 100644 test/pending/pos/t5459.scala (limited to 'test/pending/pos') diff --git a/test/pending/pos/t1786.scala b/test/pending/pos/t1786.scala new file mode 100644 index 0000000000..6299eb9eae --- /dev/null +++ b/test/pending/pos/t1786.scala @@ -0,0 +1,27 @@ +/** This a consequence of the current type checking algorithm, where bounds are checked only after variables are instantiated. + * I believe this will change once we go to contraint-based type inference. + * Alternatively, we can pursue a more extensive fix to SI-6169 + * + * The below code shows a compiler flaw in that the wildcard "_" as value for a bounded type parameter either + * breaks the boundary - as it result in Any - or doesn't evaluate to the boundary (as I'd hoped it to be). +*/ + +class SomeClass(val intValue:Int) +class MyClass[T <: SomeClass](val myValue:T) +class Flooz[A >: Null <: SomeClass, T >: Null <: A](var value: T) + +class A { + def f1(i:MyClass[_]) = i.myValue.intValue + def f2(i:MyClass[_ <: SomeClass]) = i.myValue.intValue + // def f3[T](i: MyClass[T]) = i.myValue.intValue + def f4[T <: SomeClass](i: MyClass[T]) = i.myValue.intValue + // def f5[T >: Null](i: MyClass[T]) = i.myValue.intValue + // def f6[T >: Null <: String](i: MyClass[T]) = i.myValue.intValue + i.myValue.charAt(0) + + // def g1[A, T](x: Flooz[A, T]) = { x.value = null ; x.value.intValue } + def g2(x: Flooz[_, _]) = { x.value = null ; x.value.intValue } + + class MyClass2(x: MyClass[_]) { val p = x.myValue.intValue } + // class MyClass3[T <: String](x: MyClass[T]) { val p = x.myValue.intValue + x.myValue.length } + // class MyClass4[T >: Null](x: MyClass[T]) { val p = x.myValue.intValue } +} diff --git a/test/pending/pos/t5459.scala b/test/pending/pos/t5459.scala new file mode 100644 index 0000000000..971e6f896d --- /dev/null +++ b/test/pending/pos/t5459.scala @@ -0,0 +1,48 @@ +trait A1 +trait A2 +trait A3 +trait L1 extends A1 with A2 with A3 + +object Test { + trait T1[-A <: A1] + trait T2[-A >: L1] + trait T3[ A <: A1] + trait T4[ A >: L1] + trait T5[+A <: A1] + trait T6[+A >: L1] + + def f1(x: T1[_]) = x + def f2(x: T2[_]) = x + def f3(x: T3[_]) = x + def f4(x: T4[_]) = x + def f5(x: T5[_]) = x + def f6(x: T6[_]) = x + // a.scala:22: error: type arguments [Any] do not conform to trait T5's type parameter bounds [+A <: A1] + // def f5(x: T5[_]) = x + // ^ + + def g1(x: T1[_ <: A1]) = x + def g2(x: T2[_ >: L1]) = x + def g3(x: T3[_ <: A1]) = x + def g4(x: T4[_ >: L1]) = x + def g5(x: T5[_ <: A1]) = x + def g6(x: T6[_ >: L1]) = x + + def q1(x: T1[_ >: L1]) = x + def q2(x: T2[_ <: A1]) = x + def q3(x: T3[_ >: L1]) = x + def q4(x: T4[_ <: A1]) = x + def q5(x: T5[_ >: L1]) = x + def q6(x: T6[_ <: A1]) = x + // a.scala:41: error: type arguments [Any] do not conform to trait T5's type parameter bounds [+A <: A1] + // def q5(x: T5[_ >: L1]) = x + // ^ + // two errors found + + def h1(x: T1[_ >: L1 <: A1]) = x + def h2(x: T2[_ >: L1 <: A1]) = x + def h3(x: T3[_ >: L1 <: A1]) = x + def h4(x: T4[_ >: L1 <: A1]) = x + def h5(x: T5[_ >: L1 <: A1]) = x + def h6(x: T6[_ >: L1 <: A1]) = x +} -- cgit v1.2.3