OCaml + XDuce

This paper presents the core type system and type inference algorithm of OCamlDuce, a merger between OCaml and XDuce. The challenge was to combine two type checkers of very different natures while preserving the best properties of both (principality and automatic type reconstruction on one side; very precise types and implicit subtyping on the other side). Type inference can be described by two successive passes: the first one is an MLlike unification-based algorithm which also extracts data flow constraints about XML values; the second one is an XDuce-like algorithm which computes XML types in a direct way. An optional preprocessing pass, called strengthening, can be added to allow more implicit use of XML subtyping. This pass is also very similar to an ML type checker. Categories and Subject Descriptors D.3.0 [Programming Languages]: General; D.3.2 [Programming Languages]: Language Classifications--Applicative (functional) languages General Terms Languages Keywords OCaml, XDuce, CDu...

• Type: Conference
• Year: 2006
• Where: ICFP
• Authors: Alain Frisch
• Keywords: Automatic Type Reconstruction, ICFP 2006, ML Type Checker, Programming Languages, Type Inference Algorithm