World: r3wp

geoff, did you read 


http://en.wikibooks.org/wiki/REBOL_Programming/Language_Features/Parse/Parse_expressions

, or some other topics in the book?

As I say, the book is fine on the low-level details - it's the higher 
level issues of designing an effective and usable dialect that I'm 
hoping to explore

For me, it is usually more difficult to design a meaningful dialect, 
than to parse it.

That's my point, I think. As I'm starting from scratch, I'm looking 
for principles, examples - anything that would help me get up to 
speed...

Examples are the available dialects.

The thing that's interesting about business rules is the need to 
mix declaratory configuration with some functional-style code. So 
you end up with chains of reasoning involving a mix of data and code. 
Which is why I though Rebol might be a good way to go.

I suggest you think about what you want to do .. write it out as 
sentences and then refine them

I guess I should take a look, at the existing dialects, but they're 
a bit intimidating for a newbie. What would you suggest as Best of 
Breed examples? Something not too huge, for preference.

Graham - simple and practical - just the kind of thing I'm looking 
for

Did you look at Carl's examples?

Also I think the forth dialect examples would also be quite good

VID as an example is probably too intimidating

Where are Carl's examples - you mean the stuff in the overview? It's 
pretty minimal. If there's something I've missed I'd appreciate a 
link

Also, where is the forth dialect - not coming up on Google...

forth is a language ...  which also specialises in creating domain 
specific languages

It is used in robotics, control systems ( originally astronomy, telescopes 
)

Ah - I see what you mean. Thought that you meant that someone has 
implemented a Forth like dialect in Rebo.

A Dialect is not  related with specific coding  practices. You can 
use parsing or not.
It's just an interface. You should read the theory to begin with.

funny that most dialect start small then grow quickly, so there probably 
aren't a lot of smalish dialects around.

I think ASM dialects have been written ...

Gregg has a LOGO dialect I think ...

there is an exensive BASIC interpreter dialect, but that's also quite 
large as a learning curve.

I like Graham's idea of writing out the sentences - something to 
tangible to start from. I'm familiar with the idea from relational 
data design.

Also, there's one on reboforces.com on a screen control dialect

there's a SQL dialect too

the way I approach dialects ususally is very similar to describing 
"ideas" using real language.

A dialect is an interface to hide code complexity. It's only that.

one key thing to explore is to use the full arsenal of datatypes 
at your disposal.  some of the more obscure datatypes are VERY usefull 
in dialects.    types like  tag!  issue!   are rarely used in rebol, 
but are very usefull as variations on strings in order to classify 
them as different types of stings.

Screen control sounds good - not too big or wooly - I'll take a look. 
SQL would be directly relevant to my project, so I'll definitely 
dig that one out. Do you mean SQL-PROTOCOL or is there something 
more recent?

Maxim - thanks for the tip on the datattypes - the kind of in-the-trenches 
technique that a newbie like me would overlook.

Anyway, I think if you just get started it will fall into place

another thing which helps is to be (rather) fluent or at least aware 
in how REBOL handles the evaluation of words and how to bind words 
to different blocks.


mastering this will help you go at a new level in your dialecting. 
 keep this for your second pass at learning if you're still new to 
REBOL itself.

Well, you guys have given me a good starting point, which is what 
I was hoping for. Have to sign off but I'll get my hands dirty over 
the next couple of weeks and maybe come back with some more specific 
questions. Thanks to all!

glad to help.

Geoff, don't be afraid to sketch out ideas of your ideal language, 
with different approaches and tradeoffs, and then posting them here 
for people to comment on. Language design isn't easy, and you can 
paint yourself into a corner, or make it too hard to implement easily 
by making it do too much. 


Start small and come up with the core ideas that define the feel 
of your language, and keep other questions in mind. What are you 
descrbing? What are the things and what are the actions? Do you need 
to refer to things you've defined within the dialect, or does it 
just pre-process and build structures for regular REBOL processing?

Anyone got any tools for emitting docs in EPUB format?
Please!?

Don't know any, sorry.