es v*1* features

[John (_You_ hide, they seek.) Mackin <john@civil.su.oz.au>]

    please tell us, either by private mail or to the list, what you do
    think is missing from es.  knowing the source, job control will
    probably never be in the shell, but just about everything else is
    fair game.

OK, here's the first thing I was hoping to find that seemed, on my
reading of the source, to be missing: the ability to specify a user-defined
function that would be invoked on a history-file write.  Invoking the
function would then take the place of writing the file (or, maybe,
the file would still be written with what the function returned, unless
the function returned '').  The function should get at least two
arguments: the first being the string comprising the line to be
written, and the second being a boolean saying what the shell is
going to do after this line: true = it's going to be executed;
false = the shell is going to print $prompt(2) and read more input.
I can't think of any other useful arguments but maybe there are some.

OK,
John.