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Compiler crash: Implicit Function types + SAM #4611

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allanrenucci opened this issue Jun 1, 2018 · 1 comment
Closed

Compiler crash: Implicit Function types + SAM #4611

allanrenucci opened this issue Jun 1, 2018 · 1 comment
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@odersky @allanrenucci
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area:transform itype:crash

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@allanrenucci
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trait Responder[T] {
  def responseFor(value: T): implicit Request => T
}

object Responder {
  val responseResponder: Responder[Response] =
    response => response
}

class Response
class Request
exception occurred while compiling tests/allan/Test.scala
Exception in thread "main" scala.MatchError: ArrayBuffer(<SingleDenotation of type MethodType(List(value), List(TypeRef(ThisType(TypeRef(NoPrefix,module class <empty>)),class Response)), AppliedType(TypeRef(ThisType(TypeRef(NoPrefix,module class scala)),class ImplicitFunction1),List(TypeRef(ThisType(TypeRef(NoPrefix,module class <empty>)),class Request), TypeRef(ThisType(TypeRef(NoPrefix,module class <empty>)),class Response))))>, <SingleDenotation of type MethodType(List(value), List(TypeRef(ThisType(TypeRef(NoPrefix,module class <empty>)),class Response)), MethodType(List(x$0), List(TypeRef(ThisType(TypeRef(NoPrefix,module class <empty>)),class Request)), TypeRef(ThisType(TypeRef(NoPrefix,module class <empty>)),class Response)))>) (of class scala.collection.mutable.ArrayBuffer)
	at dotty.tools.dotc.transform.ExpandSAMs.transformBlock(ExpandSAMs.scala:46)
	at dotty.tools.dotc.transform.MegaPhase.goBlock(MegaPhase.scala:668)
        ...

Initially reported by @jeffmay on Gitter
@jeffmay
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jeffmay commented Jun 1, 2018

Woah, nice simplification!

Also, my dotty version was 0.9.0-bin-20180529-be6ae0e-NIGHTLY and the full project (on a branch) is https://github.com/jeffmay/context-in-dotty/tree/sam-compiler-bug

allanrenucci added a commit to dotty-staging/dotty that referenced this issue Jun 5, 2018
@allanrenucci
Fix scala#4611: Change implicit function types rewriting rules
1369658 
An abstract method definition

    def m(xs: Ts): IF

is expanded to:

    def m(xs: Ts): IF = implicit (ys: Us) => m$direct(xs)(ys)
    def m$direct(xs: Ts)(ys: Us): R

An overriding method definition

    override def m(xs: Ts): IF = implicit (ys: Us) => E

is expanded to:

    def m$direct(xs: Ts)(ys: Us): R = E
allanrenucci added a commit to dotty-staging/dotty that referenced this issue Jun 26, 2018
@allanrenucci
Fix scala#4611:
9da3e3d 
class and trait with a single abstract method which result type is an
implicit function type are not considered SAM types anymore. The reason
is because the abstract member desugar to mutiple ones. E.g.

```scala
trait Foo {
  def foo(): implicit Int => Int
}

// becomes
trait Foo {
  def foo(): implicit Int => Int
  def foo$direct(implicit x: Int): Int
}
```
allanrenucci added a commit to dotty-staging/dotty that referenced this issue Jul 13, 2018
@allanrenucci
Fix scala#4611:
1aff0f9 
class and trait with a single abstract method which result type is an
implicit function type are not considered SAM types anymore. The reason
is because the abstract member desugar to mutiple ones. E.g.

```scala
trait Foo {
  def foo(): implicit Int => Int
}

// becomes
trait Foo {
  def foo(): implicit Int => Int
  def foo$direct(implicit x: Int): Int
}
```
allanrenucci added a commit to dotty-staging/dotty that referenced this issue Jul 18, 2018
@allanrenucci
Fix scala#4611:
e0ff85b 
class and trait with a single abstract method which result type is an
implicit function type are not considered SAM types anymore. The reason
is because the abstract member desugar to mutiple ones. E.g.

```scala
trait Foo {
  def foo(): implicit Int => Int
}

// becomes
trait Foo {
  def foo(): implicit Int => Int
  def foo$direct(implicit x: Int): Int
}
```
allanrenucci added a commit to dotty-staging/dotty that referenced this issue Aug 3, 2018
@allanrenucci
Fix scala#4611:
9c34dd1 
class and trait with a single abstract method which result type is an
implicit function type are not considered SAM types anymore. The reason
is because the abstract member desugar to mutiple ones. E.g.

```scala
trait Foo {
  def foo(): implicit Int => Int
}

// becomes
trait Foo {
  def foo(): implicit Int => Int
  def foo$direct(implicit x: Int): Int
}
```
allanrenucci added a commit to dotty-staging/dotty that referenced this issue Aug 20, 2018
@allanrenucci
Fix scala#4611:
702a995 
class and trait with a single abstract method which result type is an
implicit function type are not considered SAM types anymore. The reason
is because the abstract member desugar to mutiple ones. E.g.

```scala
trait Foo {
  def foo(): implicit Int => Int
}

// becomes
trait Foo {
  def foo(): implicit Int => Int
  def foo$direct(implicit x: Int): Int
}
```
allanrenucci added a commit that referenced this issue Aug 20, 2018
@allanrenucci
Merge pull request #4723 from dotty-staging/fix-4611-v2
d6df02b 
Fix #4611
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