MEX, Operator Precedence

["Mark E. Shoulson" <cbmvax!uunet!CTR.COLUMBIA.EDU!shoulson>]

Chris Handley suggests that "if this [{bo}] merely raised it [the
precedence] above the _preceding_ operator, (even if that had already been
"bo"ed) if may work," thus supporting left-precedence in general but
*right* precedence among {bo}ed operators.  To my understanding, that is
the current state of affairs.  So unmarked operators group left to right,
bo-ed operators have higher precedence than those and group right-to-left.
So Chris will be happy, but we still need a more general plan.

Jacques Guy proposes we forget about getting precedence any better than
what we have and concentrate on getting RPN.  From what I've seen, it seems
that in Lojban, infix order is unmarked, *as* *is* Polish notation (prefix
notation), and Reverse Polish (postfix) is easily gotten by the marker
{fu'a}.  So we have RPN already, and that's happy.

But it still doesn't solve our problem, merely proposes a workaround.
Let's face it, people are going to want to have their nice familiar infix
(try getting someone who isn't used to it to try an HP calculator!).

I'm not sure I like John's sub-rules and sub-selma'o proposal.  It seems
like overcomplication of the grammar.  Then again, its results are
certainly the best that could be hoped for.  Needless to say, it is
important that those rules be modifyible by {ti'o} or whatever.

When I first heard of {bo} I thought that maybe you could indicate as many
shades of higher and higher precedence as you wanted simply by repeating
the {bo} (this was before I looked at the grammar or anything...), so you
could get very high-precedence addition with {*li pa su'ibobobobo pa}.
This plan is imperfectly general, counterintutive (the *more* words between
the operators, the *tighter* they bind!?), and probably impossible to put
into the grammar.  Also, people want their precedences built in when they
say things.  I'll have to think about this whole problem some more.

ObControversy:  We already do it unofficially, and people are prone to do
it all the time, so we might as well officially recognize {h} as a
possible, albeit discouraged and deplored, alloglyph of {'}.  It wouldn't
preak the A-V isomorphism or anything, and as I said, it should be
discouraged.  But we already use it in selma'o names and I think I've seen
it used in UNIX filenames which, though they can have quotes, do ugly
things to the shell if they do.  So let's make our lives a little easier...

~mark