Phase 1 of the asm/lumbda-full roadmap (ticket 0005, in-flight). Adds
the minimum-cost set of additions that lets examples/ursa-scheme.lsp —
the idiomatic Scheme port of ursa.lisp.txt — load and produce correct
results on the asm tier. No CL shim yet: that requires quasiquote,
define-macro, and case, all of which are Phase 2 / 0005.
Added:
* Rest-args in lambda — (define (f x . rest) ...). .ac_bind now
detects when the remaining param list is a raw symbol (TAG_SYM)
and binds it to the remaining arg list. Enables variadic defuns.
* cadr builtin — (car (cdr x)) fast path. Used by Zoë's
repunit-value and any CL-adjacent code.
* sort builtin — ascending insertion sort on a tagged-int list.
Non-destructive. Matches Python/C sort contract (default numeric
ordering). Implementation ~50 lines, recursive sort + insert
helpers.
* let* special form — sequential binding where each init sees the
preceding bindings' values. Fresh sf_let_star + sym_let_star_val
+ .ev_let_star branch that's a one-line variant of .ev_let (eval
init in the extended env rather than the original). TCO preserved.
Tests: 9 new asm assertions in asm/test.sh covering cadr, sort (empty
/ singleton / unsorted / already-sorted), let* (basic + sequential),
rest-args (tail-only + rest-only). Total asm suite now 158 passing.
Known limitation: the Scheme port's factor / rho depends on random
rhoff iteration. For some seeds on asm (e.g. seed=2, factor 91) the
process runs out of virtual memory before rho finds a factor. The
underlying math is correct — this is an asm heap-bump-allocator
behavior under long random-retry chains and will be addressed along
with the CL_FULL work in ticket 0005. Python and C paths unaffected.
make test-all stays green across every tier.
russell@unturf.com
8cf6f44364