[GROOVY-10714] STC: Callable, Runnable, Serializable overload preference for functional argument (closure, lambda, etc.)

• Type: Bug
• Status: Reopened
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 4.0.4
• Component/s: Static compilation

Language

groovy

• Assignee: Eric Milles
• Reporter: Christopher Smith
• Created: 01/Aug/22 16:05
• Updated: 18/Jan/24 20:22

Description

This appears to be similar to GROOVY-9881, but it's specifically in the method-overload procedure. Given a functional value type with two method overloads:

interface Try<T> {
  Try<T> andThenTry(Consumer<? super T>)
  Try<T> andThenTry(Runnable)
}

When this code is invoked from static code, the STC errors out on an ambiguous method reference even if the method type isn't:

// AWS SDK 2 DynamoDbTable
class DynamoDbTable {
  void putItem(PutItemRequest<T>)
  void putItem(Consumer<PutItemRequest.Builder<T>)
  void putItem(T)
}


@CompileStatic
class MyServiceClass {
  void doThing() {
    Try.success(putItemRequest())
      .andThenTry(table::putItem) // T for Try<T> is PutItemRequest<I>
  }
}

produces

[Static type checking] - Reference to method is ambiguous. Cannot choose between [Try<T> Try#andThenTry(Consumer<? super T>), Try<T> Try#andThenTry(Runnable)]

I think this may have something to do with the relaxed SAM matching that is used to bridge ambiguous closure syntax, but when a plain method reference is used, there's no ambiguity available.

Issue Links

• is duplicated by: GROOVY-11129 STC chooses to call a non-polymorphic method although explicit type arguments are given
• is related to: GROOVY-6189 basic SAM conversion
• is related to: GROOVY-9852 Result is already complete (IllegalStateException)
• is related to: GROOVY-9881 STC can't distinguish SAMs based on arity
• relates to: GROOVY-11010 Ambiguous method reference when expecting a SAM type
• relates to: GROOVY-10963 AIOOBE with Java lambda syntax