On Tue, Sep 02, 2008 at 10:00:16AM -0400, Joel J. Adamson adamsonj@email.unc.edu wrote:
they got the idea? Lisp machines had source debuggers for the entire operating system, and Emacs works on the same principle, with interactive debuggers available.
If you're talking about the MIT designs for LISP machines, the debugger (that is, the thing that gets control after most runtime errors) is not a source debugger. Yes, the whole system is written in LISP. Yes, you can edit the definition of a function and recompile it at any time, including from the debugger. But the debugger only knows about compiled code. That never changed through the life of the LISP machine. There is a stepper for interpreted code though. I'm using the present tense because you can run your own CADR:
http://www.unlambda.com/cadr/index.html
I don't know the details of Xerox or any other types of LISP machine.
-- Derek