www.digitalmars.com         C & C++   DMDScript  

digitalmars.D.announce - Something

reply bearophile <bearophileHUGS lycos.com> writes:
http://www.reddit.com/r/programming/comments/ehjs5/not_dependent_types_in_d/
Dec 07 2010
parent reply Andrej Mitrovic <andrej.mitrovich gmail.com> writes:
Although this is way over my league (I've never used functional
languages before), I guess invariants could help in maintaining a type
with certain properties of those dependent types..?

Well, most of the papers that describe dependent types (that I've
glanced over) use functional languages and a lot of type theory, so
it's hard to grasp exactly what are the benefits of these dependent
types, since I don't know much about either unfortunately.

On 12/7/10, bearophile <bearophileHUGS lycos.com> wrote:

 http://www.reddit.com/r/programming/comments/ehjs5/not_dependent_types_in_d/
Dec 07 2010
parent bearophile <bearophileHUGS lycos.com> writes:
Andrej Mitrovic:


Although this is way over my league (I've never used functional languages
before),<


That's easy stuff, you probably need just few hours to get used to that.



I guess invariants could help in maintaining a type with certain properties of
those dependent types..?<


Yes, invariants may replace some of the purposes of dependent types, but
currently in D invariants are verified at run-time, so the bugs are found in
different moments or later.



 Well, most of the papers that describe dependent types (that I've glanced
over) use functional languages


Some years ago the author of the ATS language has designed a small imperative
language with dependent types named Xanadu. It's limited, but shows that
functional languages are not strictly necessary:
http://www.cs.bu.edu/~hwxi/Xanadu/Xanadu.html



and a lot of type theory, so it's hard to grasp exactly what are the benefits
of these dependent


types, since I don't know much about either unfortunately.<

Behind that feature there is a complex type system and a complex inferencer,
but if you read the right articles/blog posts, I think you will be able to
understand the purposes in a short time.

Bye,
bearophile
Dec 07 2010