Two bump arenas. arena_reset_trans() runs between top-level forms;
top-level define / set! deep-copy the bound value graph into perm
via Cheney-style forwarding (pin = -1 + stashed fwd pointer in
.car/.val) so no perm cell ever points into trans. Args slice in
eval's apply path also gets explicit os.free per dispatch — without
that the rt_ensure page-per-call leak dominated and masked the
reset. test_huge peaks at ~2.6 MB under massif --pages-as-heap=yes,
down from ~525 MB pre-arena (~200x).
Replaces rt_alloc-per-cell (one 4 KiB mmap each) with arena_alloc
over 64 KiB chunks. test_huge peak under massif --pages-as-heap=yes
drops from ~525 MB to ~253 MB. Same lifetime semantics; remaining
bulk is per-call append() in eval's arg slice (rt_ensure still
mmaps page-per-call).
Demo program that lives entirely on lib/* and libwwrt.a — no @symbol
FFI of its own. The interpreter sits in lispcore.ww (exports for the
test driver); lisp.ww is a 3-line entry that calls lispcore.repl().
Language surface: integers, floats, symbols, strings, lists, lambdas
with closures, define / set! / if / quote / let / begin, recursion
(fact / fib / ackermann / gcd), map / filter / reduce as user code.
REPL is line-buffered: each read tries to parse one top-level form,
asks for more on "unterminated list", evaluates and prints, then
shifts consumed bytes off the front of the buffer. Lookahead-aware —
the parser primes one extra token so we shift to L.curstart, not
L.pos, otherwise the first byte of the next form gets eaten.
lisp_test.ww exec'd as a regular binary (ww test drops -I in single-
file mode); 66 probes cover arithmetic, lists, closures, recursion,
errors. test_*.lisp drive the live REPL through `make demo`.
The wwstage cgen still mis-lowers a handful of patterns at this
shape of program — top-level array indexing, global-ptr deref,
two-level field stores, f64 routing through *T, alloc(structlit{})
for f64/str fields, (slice | E) returns, xs[i].kind chains, f64
compound assigns. Each workaround is annotated at its use site;
the full taxonomy is in examples/lisp/CLAUDE.md.
Exercises match/yield/?/!/alloc/free/slice/tagged-union end-to-end:
the @symbol FFI binds initscr/mvaddch/init_pair/getch/napms; setup
returns (*void | initerr) propagated via `?`; main unwraps the clock
via `!`; dispatch is a nested match-as-expression that yields a
bool; key handlers fold into switch/enum (q/space) and (i32 |
speederr | void) for 1..4 + the '0' error overlay.
No definite or indirect leaks under valgrind (the only "possibly
lost" / "still reachable" bytes are libncurses's process-lifetime
terminfo caches, freed only with --with-leaks).
Plan 9-style w-prefix on the per-arch tools, disambiguating from the
real Plan 9 6c/6a/6l in ref/plan9front/:
cmd/wwc/ → cmd/wcc/ libwwc.a → libwcc.a
cmd/6{c,a,l} → cmd/w6{c,a,l} binary names too
test/wwc/ → test/wcc/ 6 test files w/ w6 prefix
selfhost/cmd mirror in lockstep
bootstrap/amd64/{w6c,w6a,w6l} snapshot binaries (gitignored)
WW_6{C,A,L} → WW_W6{C,A,L} env-var overrides
Plan 9 source-tree refs ("Plan 9 6c shape", ref/plan9front/, etc.)
preserved. Hare-style driver, both C and ww sides:
ww test [path] discover *_test.ww in a directory module, run
each; single-file mode for `ww test foo.ww`
Module-by-name `ww build foo` resolves to foo.ww or foo/foo.ww
via search path (cwd : -I dirs : $WW_LIB)
Default-to-cwd `ww build` / `ww test` build the cwd module
Run pass-through `ww run path arg1 arg2` reaches the program
lib/os: getcwd (79) and getdents64 (217) syscalls power `.` resolution
and directory enumeration on the ww side.
Makefile: wwstage tool deps now include lib/os/os.ww (+ lib/strconv
for wwdump_ww) so lib/* edits force their rebuild instead of leaving
stale binaries — surfaced when test 995 first failed against a stale
w6c_ww built before the lib/os additions.
Test 993 byte-identical parity gate (C-side ww vs ww-side ww_ww on a
build corpus) stays green; all 19 tests pass.
Small interactive demo wired through the new dynamic linker.
Uses libncurses and libc via @symbol bindings; the Makefile
runs the unmodified `ww build` pipeline with -l ncurses -l c
-L /usr/lib. Resulting binary has libncurses.so.6 + libc.so.6
in NEEDED.
Workaround: state struct keeps no array fields and threads the
xs/ys body buffers through main()'s frame, because the current
6c codegen segfaults on `&struct.field`. Once that's fixed the
arrays can move into state and place_food / step / render lose
their *i32 parameters.
