Re: [pure-lang-users] Parsing Question

[Albert G. <Dr....@t-...>]

Libor Spacek wrote:
> Why are "commands" not terminated by semicolons as well?

Because they are special. Everything that's listed under "INTERACTIVE
USAGE" in the manpage does *not* belong to the Pure language at all, and
is parsed and processed in a *very* different way (more like shell
command lines).

>  stats on;
> stats: invalid parameter 'on;' (must be 'on' or 'off')
> 
> Is this inconsistency intended?

Yes. Those commands *are* special, they have nothing in common with Pure
expression syntax, and that should be very clear. What I *could* do is
require a special escape character, like the '!' in front of shell
escapes. So you'd type something like:
	:stats on
instead of just:
	stats on

That would be an easy change in the parser. Personally, I think that
this would be rather inconvenient. But I'll consider to do that change
if a big majority prefers it that way. So let's have a poll. :)

[ ] Yes, escape character please!	:stats on
[ ] No, keep it like it is!		stats off

> I have to remember which commands I defined and which were predefined and,
> in each case, use or not use a semicolon.

You *don't* define any commands. What you define are Pure functions and
variables, and this is all done in the Pure syntax. The special commands
are fixed and hard-wired, there's no way you can define new ones.

Albert

-- 
Dr. Albert Gr"af
Dept. of Music-Informatics, University of Mainz, Germany
Email:  Dr....@t-..., ag...@mu...
WWW:    http://www.musikinformatik.uni-mainz.de/ag