[lojban] Re: "zo da bu" should not be valid (was Re: Re: My parser, SI, SA, and ZOI)

[Robin Lee Powell <rlpowell@digitalkingdom.org>]

On Wed, May 12, 2004 at 11:30:29PM -0700, Robin Lee Powell wrote:
> I've spent a good portion of my free time since you posted this
> thinking about this issue.  It turns out that the answer is "Yes".
> 
> There's a simple reason for this: it's the only solution that fits the
> current cmavo definitions.
> 
> zo takes a single Lojban word.  bu takes a single Lobjan word.  si
> takes as single word, or an arbitrary string of non-Lojban text.
> 
> This is how they are defined.

There's something else that's worth mentioning: I've made the general
meta-decision that a string of si keeps eating text; it doesn't get
re-evaluated until the string of si is done.  This is enshrined in canon
in the form of the 4-si-for-zoi rule.

That was probably incomprehensible.  Here's an example:

zoi gy broda gy si si gy -- what happens to the second si?

There are two possible answers: "It gets re-evaluated", so we are left
with:

zoi gy broda si gy

because si has no meaning inside of a zoi clause, and by erasing the
zoi closer we opened up a zoi clause, which then eats the si.

The other answer is: "It keeps eating text", so we are left with:

zoi gy gy

I've taken the latter position.

The reason is simple: the former position is untenable.  Completely.  It
makes it totally impossible to use si to erase zo, zoi, and possibly
lo'u.  Try it, you'll see.  "zo da si si si si ...", for example: if
interpreted in the former fashion, every odd si erases the word before
it (which except for the first means it's erasing a si that got caught
by zo) and every even si gets caught by zo.

I'm mentioning all this partly on general principles and partly because
I just had to add a special case for "ZO SI SI" into the SI handling
rules in my PEG grammar to thwart the grammar's default behaviour given
how SI and ZO are defined which is (you guessed it) to re-evaluate in
place, leading to the infinite repitition shown above.

This amused me.[1]

There were already such rules in places for the five cases of ZOI and
SI; the lack of such a rule for ZO goes back to me mis-understanding ZO
and having it and its argument turn into a single word from the POV of
the rest of the grammar.

-Robin

[1]: The fact that my grammar trying to do silly things with infinite,
non-escapable repitition was amusing enough to me to cause me to write
this giant e-mail is almost without question a sign of deep mental
pathology, or something.

-- 
http://www.digitalkingdom.org/~rlpowell/  ***  I'm a *male* Robin.
"Many philosophical problems are caused by such things as the simple
inability to shut up." -- David Stove, liberally paraphrased.
http://www.lojban.org/  ***  loi pimlu na srana .i ti rokci morsi