1. What is a dependent type 1. ADT -- the simplest dependent-type 2. Singleton types 3. Branding: type proxies 2. Lightweight static capabilities 1. Abstract and Introduction 2. Formalization and proofs 3. Accompanying source code 3. The question of verification 4. Genuine Dependent-type systems This is a joint work with Chung-chieh Shan. We describe several approaches to lightweight dependent-type programming, letting us gain experience with dependent types on existing programming language systems All these lightweight approaches rely on type-level proxies for values, so we can statically express properties (e.g., equality, inequality) of the values that are not generally known until the run time. ``This much is clear: many programmers are already finding practical uses for the approximants to dependent types which mainstream functional languages (especially Haskell) admit, by hook or by crook.''
Idris is an experimental language with full dependent types. Dependent types allow types to be predicated on values, meaning that some aspects of a program's behaviour can be specified precisely in the type. The language is closely related to Epigram and Agda. The aims of the project are: * To provide a platform for realistic programming with dependent types. By realistic, we mean the ability to interact with the outside world and use primitive types and operations. This includes networking, file handling, concurrency, etc. * To show that full dependent types do not mean we have to abandon the functional style we have come to know and love with languages like Haskell and OCaml. lightweight dependently typed programming means allowing the programmer full access to values in types, and letting the type checker do the hard work so you don't have to! Future plans include some more useful syntax (local definitions/where clauses being the most important), a compiler,
# Please note that Dependent ML (DML) is no longer under active development. As a language, it has already been fully incorporated into ATS. # Dependent ML (DML) is a conservative extension of the functional programming language ML. The type system of DML enriches that of ML with a restricted form of dependent types. This allows many interesting program properties such as memory safety and termination to be captured in the type system of DML and therefore be verified at compiler-time. # DML The current (undocumented) implementation of a DML type-checker can be found here, which is written in Objective Caml. The syntax of DML can be readily learned from the various examples included in the distribution given that one is already familiar with Standard ML. Also, termination checking is supported in this implementation. # de Caml is the Caml-light compiler extended with a front-end supporting DML style dependent types.