Allan Adler  <ara@nestle.ai.mit.edu> wrote:
+---------------
| As an exercise, I'm thinking of writing an implementation of a minimal
| version of lisp. I expect that it would probably be based on an old
| version of lisp, predating the advent of common lisp...
+---------------

Why? You should be able to write a minimal but usable Lisp which is a
subset[1] of Common Lisp, which would give you the advantage of being
able to host the development on an existing CL implementation until you
can get it complete enough to be self-hosting.


-Rob

[1] The requirements for a Lisp being considered a "subset of Common Lisp"
are pretty minimal. See CLHS "1.7 Language Subsets":

        For a language to be considered a subset, it must have the property
        that any valid program in that language has equivalent semantics
        and will run directly (with no extralingual pre-processing, and
        no special compatibility packages) in any conforming implementation
        of the full language.

-----
Rob Warnock			<rpw3@rpw3.org>
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