[E-Lang] pending revision of E in a Walnut

[Marc Stiegler]

I have just started a major pass over E in a Walnut. So anyone who has
comments on the book that they'd like to see incorporated in this pass,
please feel free to send them to me sooner rather than later :-) This pass
will not be a completion pass, i.e., there will still be sections unwritten,
and there will still be red sections of notes on things to do, but I do
intend this time to run all the examples against the E interpreter and make
sure there are no foolish syntax errors (which means, if markm tries to make
more  syntax changes in the future, I will be seriously unhappy, since I
will have to do it all again :-)

I wanted to thank Alan Karp for his review of the current version of the
book, which I can now see took a great deal of effort; all his easy
questions will be addressed in the next version, though some of the hard
ones, which deal with the design of the language rather than the flaws of
the book itself, I am going to refer to markm.

I am not all the way through Alan's comments, but one proposal for an upward
compatible enhancement to the language caught my attention. Could/should the
when-catch construct include a "finally" clause like the try-catch? Alan
noted that one of my examples would be simpler if we had such a beast. If it
is falling-off-a-log easy, I think it is a good idea.

--marcs