Wrapping up the first two courses

[John Rose]

On Apr 25, 2019, at 2:37 PM, John Rose <john.r.rose at oracle.com> wrote:
> 
> TL;DR: - Before, and watch out for \u00XX, - Disallow, 
> - Disallow, - (see next) - Support \LineTerminator as
> both explicit layout control and opt-out (no \-).

P.S. One more argument in favor of doing \LineTerminator
now, which is even better than "it's more economical
than \-":

2D MLS's, with rectangle extraction, endow newlines,
spaces and tabs with lexical significance.  They are
no longer passive payload characters, but instead
they join quote " and backslash \ as active delimiting
characters.  It would be, now that I think of it, crazy
*not* to allow *all three* of them to be escaped.

(Yes, the mostly-invisible tab character should be
escapable, if it is semantically significant to rectangle
boundaries.)

(And, yes, these extra escapes will sometimes cause
columns not to line up.  That's life with escapes.)

Whether \LineTerminator also gobbles up following
horizontal space is a separate question.  But if space
or tab can be escaped, then it's trivial to indicate
a space or tab that should not be gobbled by \LT.
You just escape it.  And since LT is a 2D feature,
it is not wrong to consider allowing it to gobble
in 2 dimensions.