Peter Landin Semantics Seminar 2014

On correspondences between programming languages and semantic notations

Peter D Mosses

BCS FACS – Annual Peter Landin Semantics Seminar 2014, 8 December 2014, London

50 years ago, at the IFIP Working Conference on Formal Language Description Languages, Peter Landin presented a paper on “A formal description of ALGOL 60”. In it, he explained “a correspondence between certain features of current programming languages and a modified form of Church’s λ-notation”, and suggested using that as the basis for formal semantics. He regarded his formal description of ALGOL 60 as a “compiler” from ALGOL abstract syntax to λ-notation.

10 years later, denotational semantics was well established, and two denotational descriptions of ALGOL 60 had been produced as case studies: one in the VDM style developed at IBM-Vienna, the other in the continuations-based style adopted in Christopher Strachey’s Programming Research Group at Oxford.

After recalling Landin’s approach, this talk illustrated how it differs from denotational semantics, based on the cited ALGOL 60 descriptions. Familiarity with the main concepts of denotational semantics was assumed.

Slides (PDF, 17.7MB): landin-seminar-2014