mes/HACKING

-*-mode:org-*-

* Booting from LISP-1.5 into Mes

Mes started out experimenting with booting from a hex-coded minimal
LISP-1.5 (prototype in mes.c), into an intepreted full-flegded Scheme.

When EOF is read, the LISP-1.5 machine calls loop2 from loop2.mes,
which reads the rest of stdin and takes over control.  The functions
readenv, eval and apply-env in mes.mes introduced define, define-macro
quasiquote and macro expansion.

While this works, it's amazingly slow.  We implemented a full reader
in mes.c, which makes running mes:apply-env mes:eval somewhat
bearable, still over 1000x slower than running mes.c.

Bootstrapping has been removed and mes.c implements enough of R3RS to
run a macro-based define-syntax and syntax-rules.

loop.mes and mes.mes are unused and lagging behind.  Probably it's not
worth considering this route without a VM.  GNU Epsilon is taking the
more usual VM-route to provide multiple personas.  While that sounds
very cool, Lisp/Scheme, bootstrapping and trusted binaries are
probably not in scope as there is no mention of such things; only ML
is mentioned while Guile is used for bootstrapping.

mes.c is ~1200 lines which seems much too big to start translating it
to assembly/hex.

* Garbage collection
Mes is using malloc without freeing anything, memory is patient these
days :-)

* The [GuixSD] boostrap binaries
** Run a C parser on Mes
*** Run simple PEG on Guile
*** Run simple PEG on Mes
*** Find/port a PEG C and parse minimal C program
*** Generate an executable from this C-AST
*** Find a tiny C compiler that can compile gcc
** Run lalr on Mes
*** Get paren.scm test running
*** Translate cgram.y into lalr, generate AST