Abstract
The type system in the Dart programming language is deliberately designed to be unsound: for a number of reasons, it may happen that a program encounters type errors at runtime although the static type checker reports no warnings. According to the language designers, this ensures a pragmatic balance between the ability to catch bugs statically and allowing a flexible programming style without burdening the programmer with a lot of spurious type warnings. In this work, we attempt to experimentally validate these design choices. Through an empirical evaluation based on open source programs written in Dart totaling 2:4 M LOC, we explore how alternative, more sound choices affect the type warnings being produced. Our results show that some, but not all, sources of unsoundness can be justified. In particular, we find that unsoundness caused by bivariant function subtyping and method overriding does not seem to help programmers. Such information may be useful when designing future versions of the language or entirely new languages.
| Original language | English |
|---|---|
| Title of host publication | DLS 2016 - Proceedings of the 12th Symposium on Dynamic Languages |
| Editors | Roberto Ierusalimschy |
| Number of pages | 12 |
| Publisher | Association for Computing Machinery |
| Publication date | 1 Nov 2016 |
| Pages | 13-24 |
| ISBN (Print) | 978-1-4503-4445-6 |
| ISBN (Electronic) | 9781450344456 |
| DOIs | |
| Publication status | Published - 1 Nov 2016 |
| Event | SPLASH 2016: Systems, Programming, and Applications - Amsterdam, Netherlands Duration: 30 Oct 2016 → 4 Nov 2016 http://2016.splashcon.org/ |
Conference
| Conference | SPLASH 2016 |
|---|---|
| Country/Territory | Netherlands |
| City | Amsterdam |
| Period | 30/10/2016 → 04/11/2016 |
| Internet address |
Keywords
- Gradual typing
- Language design
- Type systems