On Aug 18, 2006, at 6:28 AM, Ramon Leon wrote:

>>
>
> Seems to me the difference between
>
> name: my name, id: 0, number of agents: 200, target function:  
> 30sphere,
> maximum error: 1e-10, visualize
>
> And this
>
> TrialRun name: 'my name'; id: 0; numberOfAgents: 200; targetFunction:
> #30sphere; error: 1e-10; visualize: true
>
> Are so trivial, why bother with the parsing step at all, just use  
> direct
> Smalltalk syntax, if kids can learn Smalltalk, so can users of a  
> DSL.  As
> far as samples of DSL's go, I use one daily in the Seaside  
> framework for
> generating html http://www.seaside.st/Documentation/ 
> GeneratingHTML/, and
> another http://scriptaculous.seasidehosting.st/, for generating  
> JavaScript.
> Both I think are good examples of embedded DSL's in Smalltalk in  
> daily use.
>
>

First, thank you so much for the samples. I'll look at them as soon  
as I have time.

As far as justifying the parsing step, my main motivation is to have  
a config file that non-programmers can easily read. I don't want them  
to have to learn anything (or as little as possible). I would like it  
to be simple to write or change by hand too--so they can script their  
own series of trials--but that's a secondary consideration. For the  
actual trial runs, I'll undoubtedly create a large config file  
automatically, in order to ensure a thorough coverage of the possible  
permutations.

But non-programmer readability is the reason I'd love to have multi- 
word selectors (instead of things_like_this or thingsLikeThis), and  
the reason I'd like to avoid strange punctuation (like => or the  
Smalltalk semicolons, or syntax to indicate that something is a  
string or symbol). And, finally, I'd like to get rid of any  
unnecessary words (new_run and TrialRun new)--unless I have different  
types of runs, it's just uninformative boilerplate.

Also, the parsed version could easily be case insensitive, allowing  
me to switch to something like this (if I thought it added clarity):

NAME: my name, ID: 0, NUMBER OF AGENTS: 200, TARGET FUNCTION:  
30Sphere, MAXIMUM ERROR: 1e-10, visualize

Or if I was just varying one parameter, and wanted to highlight it, I  
could use all caps for just that selector.

But it's only worth it if it's simple to implement. Case  
insensitivity is trivial. As is stripping off leading (or trailing)  
boilerplate. Replacing 'number of agents' with 'numberOfAgents' is  
also trivial, as is switching from commas to semicolons.

The only slightly tricky part is automatically adding quotes to  
strings and # to symbols--so I may just leave that out.

-Rich-