Types for Flexible Objects

@inproceedings{Palmer2014TypesFF,
  title={Types for Flexible Objects},
  author={Zachary Palmer and Pottayil Harisanker Menon and Alexander Rozenshteyn and Scott F. Smith},
  booktitle={APLAS},
  year={2014}
}
Scripting languages are popular in part due to their extremely flexible objects. Features such as dynamic extension, mixins, and first-class messages improve programmability and lead to concise code. But attempts to statically type these features have met with limited