[Ur] haskell interface

[Adam Chlipala]

Sergey Mironov wrote:
> Hello, community! I am currently very new to UrWeb (just read FAQs,
> manual and watched demo), but have some experience in Haskell. I find
> Ur/Web approach to web development to be very interesting and want to
> try it but absence of libraries I used to employ is bothering me. I
> mean different parsers, image processing,

Certainly these pieces are probably best implemented outside of Ur/Web 
(though see the Ur/Web feed parsing library for a counterexample, which 
is quite low performance for now).  You'll find a section in the manual 
explaining the foreign function interface, which allows very natural 
interfacing with C or JavaScript.  The thing to watch out for is 
Ur/Web's transactional approach to all state; beyond that, it should be 
possible to interface easily with any language that exports a simple C 
interface.

> OS integration like server-side processes or shared mem.

This part I don't understand.  There are certainly "server-side 
processes" involved with any compiled Ur/Web application!  If you 
describe precisely what functionality you want to implement, I may be 
able to explain how Ur/Web already supports it.