Re: 10 problems with Elisp, part 10

[Richard Stallman <rms@gnu.org>]

[[[ To any NSA and FBI agents reading my email: please consider    ]]]
[[[ whether defending the US Constitution against all enemies,     ]]]
[[[ foreign or domestic, requires you to follow Snowden's example. ]]]

  > > My point is that the buffer as abstraction is already pretty good.

  > Indeed.  As is looking-at and beginning-of-line, btw.

I dont know of an editor which doesn't have a concept of buffers or
the buffer.  However, the GNU Emacs approach, where you move poimt and
then call fuctions which operate at poit, is not the only possible way.

Shortly before writing GNU Emacs, I maintained Zwei, the second
Emacs-like editor for the MIT Lisp Machine.  In Zwei, every function
to operate on text required specifying a start and end position as
arguments -- one or wo of them.  Point and the mark existed for users,
but the main calling covention for functions to operate on text was
that you stored positions in Lisp varianles and set point or the mark
only for the user's benefit.

After working with that for a douple of years, I was convinced that
that was clunky, and using point and mark was a better Lisp calling
interface.

In addition, this made it possible to call a function from Lisp just
like the way a user would invoke the same command for editing.  It was
usually convenient to have just one function to call, convenient from
Lisp code and as a user command.

In Zwei one usually needed two different functions for each operation
on text, one to be the keyboard command and one to operate on
a position and return a position.  In GNU Emacs, there is just one
and it works in both ways.

I designed `interactive' to make it easier to do that.

When people criticize this functiob/command calling convention,
it is not clear to me what other alternative they would prefer.

-- 
Dr Richard Stallman (https://stallman.org)
Chief GNUisance of the GNU Project (https://gnu.org)
Founder, Free Software Foundation (https://fsf.org)
Internet Hall-of-Famer (https://internethalloffame.org)