# Dependent type

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EndreyMark (Talk | contribs) (Adding a new section ,,Simulating them [dependent types in Haskell]''. Links to wikipages: how to achieve static type checks instead of runtime assertions. Link to Smart constructors wikipage) |
EndreyMark (Talk | contribs) (Referring to HaskelDB, as a practical case study on the usefulness of such idioms (i.e. those related to simulating dependent types)) |
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* [http://haskell.org/hawiki/SimulatingDependentTypes SimulatingDependentTypes] of HaWiki | * [http://haskell.org/hawiki/SimulatingDependentTypes SimulatingDependentTypes] of HaWiki | ||

* [[Smart constructors]] | * [[Smart constructors]] | ||

+ | * On the usefulness of such idioms in practice, see HaskellBD's [http://haskelldb.sourceforge.net/ updated] and [http://www.haskell.org/haskellDB/ original] pages | ||

[[Category:Theoretical foundations]] | [[Category:Theoretical foundations]] |

## Revision as of 11:00, 6 March 2006

## Contents |

# 1 The concept of dependent types

## 1.1 General

Dependent Types in Programming abstract in APPSEM'2000

## 1.2 Type Theory

Simon Thompson: Type Theory and Functional Programming. Section 6.3 deals with dependent types, but because of the strong emphasis on Curry-Howard isomorphism and the connections between logic and programming, the book seemed cathartic for me even from its beginning.

## 1.3 Illative Combinatory Logic

To see how Illative Combinatory logic deals with dependent types, see combinator **G** described in Systems of Illative Combinatory Logic complete for first-order propositional and predicate calculus by Henk Barendregt, Martin Bunder, Wil Dekkers.
It seems to me that the dependent type construct
of Epigram corresponds to
in Illative Combinatory Logic. I think e.g. the followings should correspond to each other:

# 2 Dependently typed languages

## 2.1 Epigram

Epigram is a full dependently typed programming language see especially

- Epigram Tutorial by Conor McBride
- and Why dependent types matter by Thorsten Altenkirch, Conor McBride and James McKinna).

Dependent types (of this language) also provide a not-forgetful concept of **views** (already mentioned in the Haskell Future;
the connection between these concepts is described in p. 32 of Epigram Tutorial (section *4.6 Patterns Forget; Matching Is Remembering*).

## 2.2 Other techniques

APPSEM Workshop on Subtyping & Dependent Types in Programming

# 3 Dependent types in Haskell programming

## 3.1 Proposals

John Hughes: Dependent Types in Haskell (some ideas).

## 3.2 Simulating them

- SimulatingDependentTypes of HaWiki
- Smart constructors
- On the usefulness of such idioms in practice, see HaskellBD's updated and original pages