WG211/M15Tratt

Fine-grained language composition by Laurence Tratt, Software Development Team, King's College London [1]

Although run-time language composition is common, it normally takes the form of a Foreign Function Interface (FFI). While useful, such compositions tend to be coarse-grained and slow. In this talk I will show how rich languages can be composed in a fine-grained manner, allowing users to embed syntactic fragments of different languages inside each other, including referencing variables across languages. We show that sensible cross-language design decisions can be made in the face of different semantics, and that composed programs have a surprisingly low performance overhead.