[Ur] A direction for Ur/Web

[Karn Kallio]

> >> What about a wiki page ? SASS/HAML could be implemented as well. It
> >> looks like it doesn't make sense to implement all features of
> >> haml-lang.com. But most of its syntax is much nicer to write.
> > 
> > I do not think that HAML or SASS add any abstractions that Ur/Web with a
> > full CSS support would not already have.  So in that sense implementing
> > them would not gain anything.  If Ur/Web gained a sort of a typed macro
> > system allowing user level implementation of SASS/HAML as a syntactic
> > DSL that would be really interesting.
> 
> Why would a "macro system" be needed?  You can get a long way with
> 
> string parsing.  See, for example, this HTML parser:
>      http://hg.impredicative.com/meta/file/d05943db55e8/html.urs

Some sort of multistaging mechanism (right, not "macros") would be needed to 
allow programmers to prepare type safe source code containing Sass and Haml 
syntax.  Runtime parsers are perfect for supporting things like BBcode in 
forums.  I was conjuring up some imaginary facility for programmers to define 
their own DSL/syntax that would elaborate into well typed Ur/Web or something.  
I realize this would be a research campaign ... take it in the spirit of 
wildly suggesting a possible "far far future" direction for Ur/Web.