Colloquium Computer Science - Prof. P.D. Mosses University of Swansea

Title: CBS: Component-based specification of programming languages

Abstract:
CBS is a framework for component-based specification of programming
languages. Its aim is to reduce the effort of formal language
specification, and thereby encourage language developers to exploit
formal semantics more widely.

CBS provides a library of reusable language specification components
called 'funcons' (fundamental constructs). They generally correspond
to familiar features of mainstream programming languages, and the
semantics of a language is specified by analysing its constructs as
compositions of funcons. When a language evolves, the analysis of its
unaffected constructs does not change. Moreover, adding new funcons to
the library does not involve changes to the definitions of previous
funcons.

In this talk, we first introduce and illustrate the main features of
CBS. We then demonstrate how easily a specification of a pure
functional programming language can be extended when mutable variables
and concurrent threads are added. Development and validation of CBS
specifications are supported by an IDE (implemented in Spoofax) and a
Haskell package for generating modular funcon interpreters from funcon
definitions.

CBS has been developed by the PLanCompS project
( https://plancomps.github.io ). The beta-release of CBS provides an
initial library of funcons, and examples of their use in language
specifications.