We introduce the blame calculus, which adds the notion of blame from Findler and Felleisen's contracts to a system similar to Siek and Taha's gradual types and Flanagan's hybrid types. We characterise where positive and negative blame can arise by decomposing the usual notion of subtype into positive and negative subtypes, and show that these recombine to yield naive subtypes. Naive subtypes previously appeared in type systems that are unsound, but we believe this is the first time naive subtypes play a role in establishing type soundness.
|Title of host publication||Programming Languages and Systems|
|Subtitle of host publication||18th European Symposium on Programming, ESOP 2009, Held as Part of the Joint European Conferences on Theory and Practice of Software, ETAPS 2009, York, UK, March 22-29, 2009. Proceedings|
|Number of pages||16|
|Publication status||Published - 2009|
|Name||Lecture Notes in Computer Science|
|Publisher||Springer Berlin / Heidelberg|