Re: envelope test syntax?

Cyrus Daboo wrote:

> That said, I have wondered for a while whether it would not be better to 
> have a formal ABNF syntax for the commands and tests. Would that 
> actually be possible or useful?
I don't think so.  Programming languages are typically specified as 
Sieve is, in terms of tokens, a formal grammar, and a standard library. 
 We could do what you suggest--in fact, the early drafts did so.  It 
was not very readable or particularly helpful.  Extensions would have to 
extend the grammar, and that's error-prone and not at all in line with 
what programming languages usually do.  Worse, you wouldn't be able to 
parse the general language without knowing all the extensions a 
particular script used.
Tim