Lecture
This lecture delves into the challenges posed by null references in programming languages, exploring the efforts to mitigate their drawbacks while preserving compatibility with existing codebases. The speaker discusses the classification of null references in terms of optional values and object initialization, proposing practical alternatives and fundamental changes in language design. The presentation covers the implementation in Scala and its implications for new programming languages. Topics include type systems, null values, the billion-dollar mistake, Scala's approach to null, subtyping hierarchy, correctness and null safety, gradual migration strategies, and analysis boundaries in object initialization.