Re: another possible use case for invisible XML

>   * In general, start with ixml.
>
>     Even if the structure of control sequences is as simple as the regex
>     '\|[^\|]+\|', use ixml, not an editor or a transform with a bunch of
>     regex matches.  Ixml provides a record of the transformation (much
>     better than "oh, it was a couple of hours' work in Emacs").  It
>     makes it easy to handle different control sequences differently, for
>     whatever reason.

It is very unfortunate that the diagram on page 22 uses vertical bars
and those are manifest in the data:

0     1.     |w30||wid||picn| *
0     2.     |n||e|#|e|###############'exponent#part' |g|?
0     3.     |e|################|ul4||ul||ul||ulb||ul4||ul||ul| |g|?
0     4.     |e|###############|#############| |g|?
0     5.     |e|######'times#ten#to#the###'power#of#ten' |g|?
0     6.     |e|########power#choice'########|ul||ul||ul||ulb||ul||ul||ul| |g|?
0     7.     |e|#############|##############|#######| |g|?
0     8.     |e|#############|######'plusminus###'fixed#point |g|?
0     9.     |e|#############|########option'######numeral' |g|?
0    10.     |e|#############|#########|###############| |g|?


And then there’s this bit of weirdness just a little further on:

0   101.     <L2F2>|S25|S5'|S1'times#ten#to#the|S122|S5'|S1'power#of#ten|S5'|S1' *
0   102.     <LF2>|S40power#choice|S5'|S1' *
0   103.     <LF2>|S204|S5'|S1'plusminus|S130|S5'|S1'fixed#point *
0   104.     <LF2>|S223option|S5'|S1'|S159numeral|S5'|S1' *

> If anyone reading this has further advice, or different advice, I would
> be glad to hear it.

What you outline sounds plausible to me. Using a record-oriented parse,
I was able to get simple output very quickly. I struggled to write a
grammar for extracting the control sequences that wasn’t ambiguous. I’m
out of practice, I guess.

A quick python program to identify what all the unique control sequence
*are* tripped over the vertical bars in the diagram and whatever the
heck is going on in the lines that begin <Lxxx>. And the day job
beckons.

                                        Be seeing you,
                                          norm

--
Norm Tovey-Walsh
Saxonica