RE: Making ielm behave like a shell (getting to previous commands using the up-arrow key)

[Drew Adams]

> Programs do not run with `setq'
> there, it is inserted temporary to assign some variables step by step
> until I find what is wrong.

I see.  I misunderstood.  So you are not evaluating
the `let*' as written.  You are evaluating individual
`setq' sexps you added to it.

> > (_IGNORED  (setq fred  'nope-24))
> 
> I have seen it works with _ alone

Yes, of course.  I want to make it obvious to myself.

It "works" with any symbol whatsoever, no need for
"_" - that's just an informal convention.  It's all
about communicating to human readers (e.g. yourself).

> How do you debug? You use edebug-defun?

I use `debug', not `edebug'.  But many people use
`edebug'.  I use `debug-on-entry', `debug-on-error',
and explicit calls to `debug' inserted as breakpoints.

For the latter, `(debug nil SOME-SEXP)' evaluates
SOME-SEXP in the debugging context, and prints it
at the top of the debugger when it's entered.  So
it acts like an extra call to `message' (more
precisely, it does an implicit `e').

> > > How would you do message calls there?

I showed that in a few places - please review my
message - search for `message'.

> That I did not understand. Why now show example of message call? What
> is it? Do you mean (message something)?

Yes.  And I did show examples of it.

> Useful function. Is there anyway to get out of debug and continue the
> function? c does not do what I think it should do. I would like to
> exit out of debug and continue with the function. Any way?

`j' kind of does that.  `C-h m' in the debugger
tells you what's available.  See also (elisp)
`Invoking the Debugger'.