Closures: Open Issues (v0.6b)

• The specification does not define the classfile format for the "for" qualifier.
• The for keyword on a method declaration should be a qualifier.
  Meant to introduce a control abstraction method that works like a loop, "for" should be treated syntactically like a modifier rather than appearing immediately before the method name. This helps make the declaration site more similar to the use site.
• Relax the closure conversion.
  The closure conversion requires that the parameters of a closure exactly match the parameter types of the interface it is converted to. Experience with the 0.5 prototype suggests that this should be relaxed to an assignment conversion.
• Control transfers from a lambda.
  We should describe in nonnormative text the techniques used in the prototype to implement control transfers out of an expression lambda.