Gradual Typing for Smalltalk

Esteban Allende (1) , Oscar Callau (1) , Johan Fabry (2) , Éric Tanter (2) , Marcus Denker (3)

1 PLEIAD
2 DCC - Computer Science Department [Santiago]
3 RMOD - Analyses and Languages Constructs for Object-Oriented Application Evolution

Being able to combine static and dynamic typing within the same language has clear benefits in order to support the evolution of prototypes or scripts into mature robust programs. While being an emblematic dynamic object-oriented language, Smalltalk is lagging behind in this regard. We report on the design, implementation and application of Gradualtalk, a gradually-typed Smalltalk meant to enable incremental typing of existing programs. The main design goal of the type system is to support the features of the Smalltalk language, like metaclasses and blocks, live programming, and to accomodate the programming idioms used in practice. We studied a number of existing projects in order to determine the features to include in the type system. As a result, Gradualtalk is a practical approach to gradual types in Smalltalk, with a novel blend of type system features that accomodate most programming idioms.

Domaines: Langage de programmation [cs.PL]

Esteban Allende, Oscar Callau, Johan Fabry, Éric Tanter, Marcus Denker. Gradual Typing for Smalltalk. Science of Computer Programming, 2014, 96 (1), pp.52-69. ⟨10.1016/j.scico.2013.06.006⟩. ⟨hal-00862815⟩