Abstract

Extending a subtyping-constraint-based type inference framework with conditional constraints and rows yields a powerful type inference engine. We illustrate this claim by proposing solutions to three delicate type inference problems: \accurate" pattern matchings, record concatenation, and rst-class messages. Until now, known solutions required signicantly different techniques; our theoretical contribution is in using only a single set of tools. On the practical side, this allows all three problems to bene t from a common set of constraint simplication techniques, a formal description of which is given in an appendix. 1 Introduction Type inference is the task of examining a program which lacks some (or even all) type annotations, and recovering enough type information to make it acceptable by a type checker. Its original, and most obvious, application is to free the programmer from the burden of manually providing these annotations, thus making static typing a less dreary d...

Citations

203	Type inclusion constraints and type inference - Aiken, Wimmers - 1993
182	Soft typing with conditional types - Aiken, Wimmers, et al. - 1994
136	Operations on Records - Cardelli - 1990
109	Type inference for record concatenation and multiple inheritance - Wand - 1989
108	Componential set-based analysis - Flanagan, Felleisen - 1997
81	Type inference with constrained types. Theory and Practice of Object Systems - Odersky, Sulzmann, et al. - 1999
67	A polymorphic record calculus and its compilation - Ohori - 1995
60	Subtyping constrained types - Trifonov, Smith - 1996
55	A record calculus based on symmetric concatenation - Harper, Pierce - 1991
42	Set based analysis of ML programs - Heintze - 1993
36	Typing record concatenation for free - Rémy - 1994
35	Simplifying subtyping constraints: a theory - Pottier - 2001
18	Type inference in the presence of subtyping: from theory to practice - Pottier - 1998
16	Projective ML - Remy - 1992
14	Ordering constraints over feature trees - Müller, Niehren, et al. - 2000
9	Static typing for dynamic messages - Nishimura
8	Bane: A Library for Scalable Constraint-Based Program Analysis - Fähndrich - 1999
7	Automatic computation of data set de - Reynolds - 1969
6	an efficient implementation of type inference with subtyping - Wallace - 2000
6	A case study of typechecking with constrained types: Typing record concatenation. Presented at the workshop on - Rémy - 1995
2	Type inference for messages with feature constraints - Muller, Nishimura - 1998
1	Object calculi for dynamic messages - Bugliesi, Crafa - 1999
1	Subtyping-constraint-based type inference with conditional constraints: algorithms and proofs. Unpublished draft - Pottier - 1999