Core VM changes:
- Add VmClosure value variant — inner closures created by OP_CLOSURE are
first-class VM values, not NativeFn wrappers around call_closure
- Convert `run` from recursive to while-loop — zero OCaml stack growth,
true TCO for VmClosure tail calls
- vm_call handles VmClosure by pushing frame on current VM (no new VM
allocation per call)
- Forward ref _vm_call_closure_ref for cross-boundary calls (CEK/primitives)
Compiler (spec/compiler.sx):
- Define hoisting in compile-begin: pre-allocate local slots for all
define forms before compiling any values. Fixes forward references
between inner functions (e.g. read-expr referencing skip-ws in sx-parse)
- scope-define-local made idempotent (skip if slot already exists)
Server (sx_server.ml):
- JIT fail-once sentinel: mark l_compiled as failed after first VM runtime
error. Eliminates thousands of retry attempts per page render.
- HTML tag bindings: register all HTML tags as pass-through NativeFns so
eval-expr can handle (div ...) etc. in island component bodies.
- Log VM FAIL errors with function name before disabling JIT.
SSR fixes:
- adapter-html.sx letrec handler: evaluate bindings in proper letrec scope
(pre-bind nil, then evaluate), render body with render-to-html instead of
eval-expr. Fixes island SSR for components using letrec.
- Add `init` primitive to OCaml kernel (all-but-last of list).
- VmClosure handling in sx_runtime.ml sx_call dispatch.
Tests: 971/971 OCaml (+19 new), 0 failures.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
letrec in adapter-html.sx: evaluate via CEK (which handles mutual
recursion and returns a thunk), then render-value-to-html unwraps
the thunk and renders the expression with the letrec's local env.
Both islands (~layouts/header and ~home/stepper) now render
server-side with hydration markers and CSS classes.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
- trampoline resolves Thunk values (sf-letrec returns them for TCO)
- render-to-html handles "thunk" type by unwrapping expr+env
- effect overridden to no-op after loading signals.sx (prevents
reactive loops during SSR — effects are DOM side-effects)
- Added thunk?/thunk-expr/thunk-env primitives
- Added DOM API stubs for SSR (dom-query, schedule-idle, etc.)
Header island renders fully with styling. Stepper island still
fails SSR (letrec + complex body hits "Undefined symbol: div"
in eval path — render mode not active during CEK letrec eval).
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Two fundamental environment bugs fixed:
1. env-set! was used for both binding creation (let, define, params)
and mutation (set!). Binding creation must NOT walk the scope chain
— it should set on the immediate env. Only set! should walk.
Fix: introduce env-bind! for all binding creation. env-set! now
exclusively means "mutate existing binding, walk scope chain".
Changed across spec (eval.sx, cek.sx, render.sx) and all web
adapters (dom, html, sx, async, boot, orchestration, forms).
2. makeLambda/makeComponent/makeMacro/makeIsland used merge(env) to
flatten the closure into a plain object, destroying the prototype
chain. This meant set! inside closures couldn't reach the original
binding — it modified a snapshot copy instead.
Fix: store env directly as closure (no merge). The prototype chain
is preserved, so set! walks up to the original scope.
Tests: 499/516 passing (96.7%), up from 485/516.
Fixed: define self-reference, let scope isolation, set! through
closures, counter-via-closure pattern, recursive functions.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
