Tillmann Rendel wrote:

Hi,

Robert Clausecker wrote:

Image you would create your own language with a paradigm similar to

Haskell or have to chance to change Haskell without the need to keep any

compatibility. What stuff would you add to your language, what stuff

would you remove and what problems would you solve completely different?

I would try to improve the language's support for the embedding of domain-specific embedded languages (aka. combinator libraries). Such embedding requires the integration of a domain-specific language's syntax, static semantics and dynamic semantics. Some (more or less far fetched) ideas about these three areas follow.

I think this is a very good point. The things I would like to see:

* Better syntax for observable sharing. Doaitse Swierstra proposed a "grammer" construct that is basically a  let  statement where the binder names can be observed. I'm not entirely sure whether that is the most general or sufficient syntax, but something along these lines.

* Meta-programming / partial evaluation. When designing a DSL, it is often the case that you know how to write an optimizing compiler for your DSL because it's usually a first-order language. However, trying to squeeze that into GHC rules is hopeless. Having some way of compiling code at run-time would solve that. Examples:
** Conal Elliott's image description language Pan
** Henning Thielemann's synthesizer-llvm