The Hindley/Milner let-polymorphic type inference system has two different algorithms: one
is the de facto standard Algorithm 𝒲 that is bottom-up (or context-insensitive), and the other …

Advanced type systems often need some form of type inference to reduce the burden of
explicit typing, but type inference often leads to poor error messages for ill-typed programs …

Overview. This chapter provides a gentle introduction to type systems, functional languages,
and type error messages. We give examples of reported type error messages to illustrate the …

Changing a program in response to a type error plays an important part in modern software
development. However, the generation of good type error messages remains a problem for …

The type systems of most typed functional programming languages are based on the
Hindley-Milner type system. A practical problem with these type systems is that it is often …

Previous methods have generally identified the location of a type error as a particular
program point or the program subtree rooted at that point. We present a new approach that …

Localizing type errors is challenging in languages with global type inference, as the type
checker must make assumptions about what the programmer intended to do. We introduce …

The effectiveness of a type-checking tool strongly depends on the accuracy of the positional
information that is associated with type errors. We present an approach where the location …

Previous methods have generally identified the location of a type error as a particular
program point or the program subtree rooted at that point. We present a new approach that …

The ML family of strict functional languages, which includes F#, OCaml, and Standard ML,
evolved from the Meta Language of the LCF theorem proving system developed by Robin …