request for info on extensible editor

[MCB%mit-mc at sri-unix.UUCP]

From:  Michael A. Bloom <MCB at mit-mc>


Probably your best choice is one of the lisp-based emacs's
ported to run under franz lisp (which is written in C, and is
close enough to maclisp to be able to run a macsyma)

Goslin's (CMU) emacs is NOT a lisp based emacs, although it
has an extension language with a syntax similar to that of a lisp.
It most notably lacks the list manipulation primitives that make 
lisp lisp.

The lisp based emacs's I am aware of are:

    Honeywell Emacs (Maclisp)
    ZMACS ( Zeta lisp )
    NIL Emacs (NIL (for VMS, and remotely maybe for UNIX))
		NIL is currently written in BLISS and MACRO-VAX, (and NIL)
		so is not portable.

  There is also the Yale screen editor that comes as part of their
  distribution of 'T', another lisp dialect.

It might be reasonable to merge one of the Emacs lookalikes that are 
written in C with Franz lisp, so as to define a new type of data object,
the "buffer" with subr's that operate on it.  Perhaps the same
could be done for the redisplay strategy, but people like lisp based
redisplays because each person could (in theory) have his own personal
redisplay handler.

Possible candidates for this are:

    gosling's emacs, whose redisplay is considered fairly fancy.  You
    could rip out all of the mlisp stuff.

    Bell Labs Emacs, whose status is indeterminate at the moment.
    It has its own macro language made up of emacs commands with
    some flow control commands added.  I'm told that macros
    written for it resemble TECO macros to those not versed in TECO.

    CCA Emacs,  which I've seen only once and liked.

    and even MINCE, which does not have a display algorythm
    approaching the others, but is cheap (225$ for partial source)

A good general reference is "Theory and practice of Text editors",
MIT/LCS/TM-165, free from LCS Publications (as of a year ago, anyway).