FIX.org, NEXT.md, DISCUSS.org, docs/DISCUSS.md and the session handoff at the
root are one TODO.org now: 293 entries under seven subsystem headings, each
carrying an org keyword that says where it stands. A DONE entry is a few lines
saying what was decided and what that rules out; the reasoning that would not
compress — the embedding spike and the four reports the hand-written x86
backend was built from — moved into docs/BUILT.md instead, and its entries
point there in one line.
Every entry was checked against the tree before it got a keyword, and the
prose was wrong in both directions. Things the deleted files called open were
built: the first-evaluation stall, main being redefinable, macro parameter
lists, the type-limit constants, the array constructors, the byte fills,
inc/dec, the discard's fontification, the Emacs buffers, rt_die's _exit, the
backtrace surface, and the acceptance failure that could print and still exit
zero. Things they called done were not: the backend reports' no-plan buckets
had gone stale in the other direction, the value-dependent defvar was
superseded rather than built, and macro-expansion source locations are on an
unmerged lane, so that entry is NEXT and names the branch.
Every comment that cited one of the five by name now cites a heading that
exists, in TODO.org or in docs/BUILT.md. The session reports under
docs/handoffs/ keep naming the files they worked on, because rewriting them
would falsify what those sessions did; each carries a note saying where the
content went.
CLHS 4.3.6's update protocol, minus the user hook, on the dyn side's
defclass. Redefining a class used to be silent: a class is sugar for a
constructor defn, so the edit replaced a body and the instances already in
the program kept their old keys for ever.
Three pieces. A registry in flan_dyn.c holding each class's current slot
list and a generation, made only of interned kw_entry pointers so the
collector has nothing to trace in it and no root to push for it. A uint32
generation on the instance, fitted into the padding kind and mark leave in
front of len's alignment — sizeof(flan_obj) is 48 with it and was 48
without, and flan_dyn_obj_size is there so a later field that moves it
fails a test. And a registration thunk per reload, run by the agent
through flan_reload_call after the module's bodies are published: it has
to be a thunk, because the case this exists for is a class redefined and
not constructed.
Migration is lazy, at want_map, len's map arm and dyn_equal's. Slots kept
by name, gained slots nil, dropped slots gone, identity preserved, entries
rebuilt in the class's order so a migrated instance is indistinguishable
from a fresh one. Equality migrates both operands first, so it is over the
class as it is now.
The session had to stop refusing the constructor's signature change, and
does so only for a defclass and only when no compiled caller is left
behind. The checker gets there first in practice; the walk in eval holds
the reason locally rather than inheriting it.
The registry is advisory: a class instance is an open map, so a key a raw
put wrote that the class never declared is dropped by the next migration.
FIX.org says that plainly rather than pretending enforcement.
The dyn arithmetic and ordering entry points printed their sentence with no
file, no line and no column, which in a dynamic-first language is the type
error arriving from nowhere. flan_rt.c's bounds and arithmetic traps have
taken an emitter-threaded (loc, loclen) pair since they were written, and
[flan_dyn_cast_kind] is the fresh precedent on the dyn side; this is the same
pair, threaded through [arith], [want_nums] and [order] to the five
arithmetic and four ordering entry points. [eq] never traps and takes none.
The three trap printers take the pair and print nothing for a NULL loc, so
every other call site in the file — and test/dyn_ops.c, which calls the
runtime directly and has no source position — keeps its sentence byte for
byte. [trap_oom] is left alone: it is reached from [gc_alloc], which has no
site to be given and would have had to grow one on every allocation path in
the file for no reader's benefit.
