From a965731a33ed53920c2e114706d20dd6d1b33437 Mon Sep 17 00:00:00 2001
From: giles <giles.bradshaw@rose-ash.com>
Date: Sun, 5 Apr 2026 09:13:33 +0000
Subject: [PATCH] Step 10c: bind CEK special form + provide-set frame +
 scope-stack integration
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bind is now a CEK special form that captures its body unevaluated,
establishes a tracking context (*bind-tracking*), and registers
subscribers on provide frames when context reads are tracked.

- bind special form: step-sf-bind, make-bind-frame, bind continue handler
- provide-set frame: provide! evaluates value with kont (fixes peek bug)
- context tracking: step-sf-context appends to *bind-tracking* when active
- scope-stack fallback: provide pushes to scope stack for cek-call contexts
- CekFrame mutation: cf_remaining/cf_results/cf_extra2 now mutable
- Transpiler: subscribers + prev-tracking field mappings, *bind-tracking* in ml-mutable-globals
- Test fixes: string-append → str, restored edge-cases suite

Passing: bind returns initial value, bind with expression, bind with let,
bind no deps is static, bind with conditional deps, provide! updates/multiple/nil,
provide! computed new value, peek read-modify-write, guard inside bind,
bind with string-append, provide! same value does not notify, bind does not
fire on unrelated provide!, bind sees latest value, bind inside provide scope.

Remaining: subscriber re-evaluation on provide! (scope-stack key issue),
batch coalescing (no batch support yet).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
---
 hosts/ocaml/lib/sx_ref.ml           |  89 +++---
 hosts/ocaml/lib/sx_runtime.ml       |  11 +
 hosts/ocaml/lib/sx_types.ml         |   6 +-
 hosts/ocaml/transpiler.sx           |   6 +-
 spec/evaluator.sx                   | 402 +++++++++++++++++-----------
 spec/tests/test-unified-reactive.sx |  11 +-
 6 files changed, 300 insertions(+), 225 deletions(-)

diff --git a/hosts/ocaml/lib/sx_ref.ml b/hosts/ocaml/lib/sx_ref.ml
index 71dbca0b..32e6327a 100644
--- a/hosts/ocaml/lib/sx_ref.ml
+++ b/hosts/ocaml/lib/sx_ref.ml
@@ -160,7 +160,15 @@ and make_scope_frame name remaining env =
 
 (* make-provide-frame *)
 and make_provide_frame name value remaining env =
-  (CekFrame { cf_type = "provide"; cf_env = env; cf_name = name; cf_body = Nil; cf_remaining = remaining; cf_f = Nil; cf_args = Nil; cf_results = Nil; cf_extra = value; cf_extra2 = Nil })
+  (CekFrame { cf_type = "provide"; cf_env = env; cf_name = name; cf_body = Nil; cf_remaining = remaining; cf_f = Nil; cf_args = Nil; cf_results = (List []); cf_extra = value; cf_extra2 = Nil })
+
+(* make-bind-frame *)
+and make_bind_frame body env prev_tracking =
+  (CekFrame { cf_type = "bind"; cf_env = env; cf_name = Nil; cf_body = body; cf_remaining = Nil; cf_f = Nil; cf_args = Nil; cf_results = Nil; cf_extra = prev_tracking; cf_extra2 = Nil })
+
+(* make-provide-set-frame *)
+and make_provide_set_frame name env =
+  (CekFrame { cf_type = "provide-set"; cf_env = env; cf_name = name; cf_body = Nil; cf_remaining = Nil; cf_f = Nil; cf_args = Nil; cf_results = Nil; cf_extra = Nil; cf_extra2 = Nil })
 
 (* make-scope-acc-frame *)
 and make_scope_acc_frame name value remaining env =
@@ -322,6 +330,10 @@ and render_check =
 and render_fn =
   Nil
 
+(* *bind-tracking* — module-level mutable *)
+and _bind_tracking_ref = ref Nil
+and _bind_tracking_ = Nil
+
 (* *library-registry* *)
 and _library_registry_ =
   (Dict (Hashtbl.create 0))
@@ -500,7 +512,7 @@ and cek_step state =
 
 (* step-eval *)
 and step_eval state =
-  (let expr = (cek_control (state)) in let env = (cek_env (state)) in let kont = (cek_kont (state)) in (let _match_val = (type_of (expr)) in (if _match_val = (String "number") then (make_cek_value (expr) (env) (kont)) else (if _match_val = (String "string") then (make_cek_value (expr) (env) (kont)) else (if _match_val = (String "boolean") then (make_cek_value (expr) (env) (kont)) else (if _match_val = (String "nil") then (make_cek_value (Nil) (env) (kont)) else (if _match_val = (String "symbol") then (let name = (symbol_name (expr)) in (let val' = (if sx_truthy ((env_has (env) (name))) then (env_get (env) (name)) else (if sx_truthy ((is_primitive (name))) then (get_primitive (name)) else (if sx_truthy ((prim_call "=" [name; (String "true")])) then (Bool true) else (if sx_truthy ((prim_call "=" [name; (String "false")])) then (Bool false) else (if sx_truthy ((prim_call "=" [name; (String "nil")])) then Nil else (match !_symbol_resolve_hook with Some hook -> (match hook (value_to_str name) with Some v -> v | None -> raise (Eval_error ("Undefined symbol: " ^ value_to_str name))) | None -> raise (Eval_error ("Undefined symbol: " ^ value_to_str name)))))))) in (let () = ignore ((if sx_truthy ((let _and = (is_nil (val')) in if not (sx_truthy _and) then _and else (prim_call "starts-with?" [name; (String "~")]))) then (debug_log ((String "Component not found:")) (name)) else Nil)) in (make_cek_value (val') (env) (kont))))) else (if _match_val = (String "keyword") then (make_cek_value ((keyword_name (expr))) (env) (kont)) else (if _match_val = (String "dict") then (let ks = (prim_call "keys" [expr]) in (if sx_truthy ((empty_p (ks))) then (make_cek_value ((Dict (Hashtbl.create 0))) (env) (kont)) else (let first_key = (first (ks)) in let remaining_entries = ref ((List [])) in (let () = ignore ((List.iter (fun k -> ignore ((remaining_entries := sx_append_b !remaining_entries (List [k; (get (expr) (k))]); Nil))) (sx_to_list (rest (ks))); Nil)) in (make_cek_state ((get (expr) (first_key))) (env) ((kont_push ((make_dict_frame (!remaining_entries) ((List [(List [first_key])])) (env))) (kont)))))))) else (if _match_val = (String "list") then (if sx_truthy ((empty_p (expr))) then (make_cek_value ((List [])) (env) (kont)) else (step_eval_list (expr) (env) (kont))) else (make_cek_value (expr) (env) (kont))))))))))))
+  (let expr = (cek_control (state)) in let env = (cek_env (state)) in let kont = (cek_kont (state)) in (let _match_val = (type_of (expr)) in (if _match_val = (String "number") then (make_cek_value (expr) (env) (kont)) else (if _match_val = (String "string") then (make_cek_value (expr) (env) (kont)) else (if _match_val = (String "boolean") then (make_cek_value (expr) (env) (kont)) else (if _match_val = (String "nil") then (make_cek_value (Nil) (env) (kont)) else (if _match_val = (String "symbol") then (let name = (symbol_name (expr)) in (let val' = (if sx_truthy ((env_has (env) (name))) then (env_get (env) (name)) else (if sx_truthy ((is_primitive (name))) then (get_primitive (name)) else (if sx_truthy ((prim_call "=" [name; (String "true")])) then (Bool true) else (if sx_truthy ((prim_call "=" [name; (String "false")])) then (Bool false) else (if sx_truthy ((prim_call "=" [name; (String "nil")])) then Nil else (raise (Eval_error (value_to_str (String (sx_str [(String "Undefined symbol: "); name])))))))))) in (let () = ignore ((if sx_truthy ((let _and = (is_nil (val')) in if not (sx_truthy _and) then _and else (prim_call "starts-with?" [name; (String "~")]))) then (debug_log ((String "Component not found:")) (name)) else Nil)) in (make_cek_value (val') (env) (kont))))) else (if _match_val = (String "keyword") then (make_cek_value ((keyword_name (expr))) (env) (kont)) else (if _match_val = (String "dict") then (let ks = (prim_call "keys" [expr]) in (if sx_truthy ((empty_p (ks))) then (make_cek_value ((Dict (Hashtbl.create 0))) (env) (kont)) else (let first_key = (first (ks)) in let remaining_entries = ref ((List [])) in (let () = ignore ((List.iter (fun k -> ignore ((remaining_entries := sx_append_b !remaining_entries (List [k; (get (expr) (k))]); Nil))) (sx_to_list (rest (ks))); Nil)) in (make_cek_state ((get (expr) (first_key))) (env) ((kont_push ((make_dict_frame (!remaining_entries) ((List [(List [first_key])])) (env))) (kont)))))))) else (if _match_val = (String "list") then (if sx_truthy ((empty_p (expr))) then (make_cek_value ((List [])) (env) (kont)) else (step_eval_list (expr) (env) (kont))) else (make_cek_value (expr) (env) (kont))))))))))))
 
 (* step-sf-raise *)
 and step_sf_raise args env kont =
@@ -524,7 +536,19 @@ and step_sf_let_match args env kont =
 
 (* step-eval-list *)
 and step_eval_list expr env kont =
-  (let head = (first (expr)) in let args = (rest (expr)) in (if sx_truthy ((Bool (not (sx_truthy ((let _or = (prim_call "=" [(type_of (head)); (String "symbol")]) in if sx_truthy _or then _or else (let _or = (prim_call "=" [(type_of (head)); (String "lambda")]) in if sx_truthy _or then _or else (prim_call "=" [(type_of (head)); (String "list")])))))))) then (if sx_truthy ((empty_p (expr))) then (make_cek_value ((List [])) (env) (kont)) else (make_cek_state ((first (expr))) (env) ((kont_push ((make_map_frame (Nil) ((rest (expr))) ((List [])) (env))) (kont))))) else (if sx_truthy ((prim_call "=" [(type_of (head)); (String "symbol")])) then (let name = (symbol_name (head)) in (let _match_val = name in (if sx_truthy ((prim_call "=" [_match_val; (String "if")])) then (step_sf_if (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "when")])) then (step_sf_when (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "cond")])) then (step_sf_cond (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "case")])) then (step_sf_case (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "and")])) then (step_sf_and (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "or")])) then (step_sf_or (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "let")])) then (step_sf_let (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "let*")])) then (step_sf_let (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "lambda")])) then (step_sf_lambda (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "fn")])) then (step_sf_lambda (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "define")])) then (step_sf_define (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "defcomp")])) then (make_cek_value ((sf_defcomp (args) (env))) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "defisland")])) then (make_cek_value ((sf_defisland (args) (env))) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "defmacro")])) then (make_cek_value ((sf_defmacro (args) (env))) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "defio")])) then (make_cek_value ((sf_defio (args) (env))) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "io")])) then (step_sf_io (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "begin")])) then (step_sf_begin (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "do")])) then (if sx_truthy ((let _and = (Bool (not (sx_truthy ((empty_p (args)))))) in if not (sx_truthy _and) then _and else (let _and = (list_p ((first (args)))) in if not (sx_truthy _and) then _and else (let _and = (Bool (not (sx_truthy ((empty_p ((first (args)))))))) in if not (sx_truthy _and) then _and else (list_p ((first ((first (args)))))))))) then (let bindings = (first (args)) in let test_clause = (nth (args) ((Number 1.0))) in let body = (rest ((rest (args)))) in let vars = (List (List.map (fun b -> (first (b))) (sx_to_list bindings))) in let inits = (List (List.map (fun b -> (nth (b) ((Number 1.0)))) (sx_to_list bindings))) in let steps = (List (List.map (fun b -> (if sx_truthy ((prim_call ">" [(len (b)); (Number 2.0)])) then (nth (b) ((Number 2.0))) else (first (b)))) (sx_to_list bindings))) in let test = (first (test_clause)) in let result' = (rest (test_clause)) in (step_eval_list ((cons ((Symbol "let")) ((cons ((Symbol "__do-loop")) ((cons ((List (List.map (fun b -> (List [(first (b)); (nth (b) ((Number 1.0)))])) (sx_to_list bindings)))) ((List [(cons ((Symbol "if")) ((cons (test) ((cons ((if sx_truthy ((empty_p (result'))) then Nil else (cons ((Symbol "begin")) (result')))) ((List [(cons ((Symbol "begin")) ((prim_call "append" [body; (List [(cons ((Symbol "__do-loop")) (steps))])])))])))))))])))))))) (env) (kont))) else (step_sf_begin (args) (env) (kont))) else (if sx_truthy ((prim_call "=" [_match_val; (String "guard")])) then (step_sf_guard (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "quote")])) then (make_cek_value ((if sx_truthy ((empty_p (args))) then Nil else (first (args)))) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "quasiquote")])) then (make_cek_value ((qq_expand ((first (args))) (env))) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "->")])) then (step_sf_thread_first (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "->>")])) then (step_sf_thread_last (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "|>")])) then (step_sf_thread_last (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "as->")])) then (step_sf_thread_as (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "set!")])) then (step_sf_set_b (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "letrec")])) then (step_sf_letrec (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "reset")])) then (step_sf_reset (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "shift")])) then (step_sf_shift (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "deref")])) then (step_sf_deref (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "scope")])) then (step_sf_scope (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "provide")])) then (step_sf_provide (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "context")])) then (step_sf_context (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "peek")])) then (step_sf_peek (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "provide!")])) then (step_sf_provide_b (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "emit!")])) then (step_sf_emit (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "emitted")])) then (step_sf_emitted (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "handler-bind")])) then (step_sf_handler_bind (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "restart-case")])) then (step_sf_restart_case (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "signal-condition")])) then (step_sf_signal (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "invoke-restart")])) then (step_sf_invoke_restart (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "match")])) then (step_sf_match (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "let-match")])) then (step_sf_let_match (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "dynamic-wind")])) then (make_cek_value ((sf_dynamic_wind (args) (env))) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "map")])) then (step_ho_map (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "map-indexed")])) then (step_ho_map_indexed (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "filter")])) then (step_ho_filter (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "reduce")])) then (step_ho_reduce (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "some")])) then (step_ho_some (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "every?")])) then (step_ho_every (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "for-each")])) then (step_ho_for_each (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "raise")])) then (step_sf_raise (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "raise-continuable")])) then (make_cek_state ((first (args))) (env) ((kont_push ((make_raise_eval_frame (env) ((Bool true)))) (kont)))) else (if sx_truthy ((prim_call "=" [_match_val; (String "call/cc")])) then (step_sf_callcc (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "call-with-current-continuation")])) then (step_sf_callcc (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "perform")])) then (step_sf_perform (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "define-library")])) then (step_sf_define_library (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "import")])) then (step_sf_import (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "define-record-type")])) then (make_cek_value ((sf_define_record_type (args) (env))) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "define-protocol")])) then (make_cek_value ((sf_define_protocol (args) (env))) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "implement")])) then (make_cek_value ((sf_implement (args) (env))) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "parameterize")])) then (step_sf_parameterize (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "syntax-rules")])) then (make_cek_value ((sf_syntax_rules (args) (env))) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "define-syntax")])) then (step_sf_define (args) (env) (kont)) else (if sx_truthy ((prim_call "has-key?" [custom_special_forms; name])) then (make_cek_value ((cek_call ((get (custom_special_forms) (name))) (List [args; env]))) (env) (kont)) else (if sx_truthy ((let _and = (env_has (env) (name)) in if not (sx_truthy _and) then _and else (is_macro ((env_get (env) (name)))))) then (let mac = (env_get (env) (name)) in (make_cek_state ((expand_macro (mac) (args) (env))) (env) (kont))) else (if sx_truthy ((let _and = render_check in if not (sx_truthy _and) then _and else (cek_call (render_check) (List [expr; env])))) then (make_cek_value ((cek_call (render_fn) (List [expr; env]))) (env) (kont)) else (step_eval_call (head) (args) (env) (kont))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))) else (step_eval_call (head) (args) (env) (kont)))))
+  (let head = (first (expr)) in let args = (rest (expr)) in (if sx_truthy ((Bool (not (sx_truthy ((let _or = (prim_call "=" [(type_of (head)); (String "symbol")]) in if sx_truthy _or then _or else (let _or = (prim_call "=" [(type_of (head)); (String "lambda")]) in if sx_truthy _or then _or else (prim_call "=" [(type_of (head)); (String "list")])))))))) then (if sx_truthy ((empty_p (expr))) then (make_cek_value ((List [])) (env) (kont)) else (make_cek_state ((first (expr))) (env) ((kont_push ((make_map_frame (Nil) ((rest (expr))) ((List [])) (env))) (kont))))) else (if sx_truthy ((prim_call "=" [(type_of (head)); (String "symbol")])) then (let name = (symbol_name (head)) in (let _match_val = name in (if sx_truthy ((prim_call "=" [_match_val; (String "if")])) then (step_sf_if (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "when")])) then (step_sf_when (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "cond")])) then (step_sf_cond (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "case")])) then (step_sf_case (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "and")])) then (step_sf_and (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "or")])) then (step_sf_or (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "let")])) then (step_sf_let (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "let*")])) then (step_sf_let (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "lambda")])) then (step_sf_lambda (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "fn")])) then (step_sf_lambda (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "define")])) then (step_sf_define (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "defcomp")])) then (make_cek_value ((sf_defcomp (args) (env))) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "defisland")])) then (make_cek_value ((sf_defisland (args) (env))) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "defmacro")])) then (make_cek_value ((sf_defmacro (args) (env))) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "defio")])) then (make_cek_value ((sf_defio (args) (env))) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "io")])) then (step_sf_io (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "begin")])) then (step_sf_begin (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "do")])) then (if sx_truthy ((let _and = (Bool (not (sx_truthy ((empty_p (args)))))) in if not (sx_truthy _and) then _and else (let _and = (list_p ((first (args)))) in if not (sx_truthy _and) then _and else (let _and = (Bool (not (sx_truthy ((empty_p ((first (args)))))))) in if not (sx_truthy _and) then _and else (list_p ((first ((first (args)))))))))) then (let bindings = (first (args)) in let test_clause = (nth (args) ((Number 1.0))) in let body = (rest ((rest (args)))) in let vars = (List (List.map (fun b -> (first (b))) (sx_to_list bindings))) in let inits = (List (List.map (fun b -> (nth (b) ((Number 1.0)))) (sx_to_list bindings))) in let steps = (List (List.map (fun b -> (if sx_truthy ((prim_call ">" [(len (b)); (Number 2.0)])) then (nth (b) ((Number 2.0))) else (first (b)))) (sx_to_list bindings))) in let test = (first (test_clause)) in let result' = (rest (test_clause)) in (step_eval_list ((cons ((Symbol "let")) ((cons ((Symbol "__do-loop")) ((cons ((List (List.map (fun b -> (List [(first (b)); (nth (b) ((Number 1.0)))])) (sx_to_list bindings)))) ((List [(cons ((Symbol "if")) ((cons (test) ((cons ((if sx_truthy ((empty_p (result'))) then Nil else (cons ((Symbol "begin")) (result')))) ((List [(cons ((Symbol "begin")) ((prim_call "append" [body; (List [(cons ((Symbol "__do-loop")) (steps))])])))])))))))])))))))) (env) (kont))) else (step_sf_begin (args) (env) (kont))) else (if sx_truthy ((prim_call "=" [_match_val; (String "guard")])) then (step_sf_guard (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "quote")])) then (make_cek_value ((if sx_truthy ((empty_p (args))) then Nil else (first (args)))) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "quasiquote")])) then (make_cek_value ((qq_expand ((first (args))) (env))) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "->")])) then (step_sf_thread_first (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "->>")])) then (step_sf_thread_last (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "|>")])) then (step_sf_thread_last (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "as->")])) then (step_sf_thread_as (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "set!")])) then (step_sf_set_b (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "letrec")])) then (step_sf_letrec (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "reset")])) then (step_sf_reset (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "shift")])) then (step_sf_shift (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "deref")])) then (step_sf_deref (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "scope")])) then (step_sf_scope (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "provide")])) then (step_sf_provide (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "peek")])) then (step_sf_peek (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "provide!")])) then (step_sf_provide_b (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "context")])) then (step_sf_context (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "bind")])) then (step_sf_bind (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "emit!")])) then (step_sf_emit (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "emitted")])) then (step_sf_emitted (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "handler-bind")])) then (step_sf_handler_bind (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "restart-case")])) then (step_sf_restart_case (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "signal-condition")])) then (step_sf_signal (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "invoke-restart")])) then (step_sf_invoke_restart (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "match")])) then (step_sf_match (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "let-match")])) then (step_sf_let_match (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "dynamic-wind")])) then (make_cek_value ((sf_dynamic_wind (args) (env))) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "map")])) then (step_ho_map (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "map-indexed")])) then (step_ho_map_indexed (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "filter")])) then (step_ho_filter (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "reduce")])) then (step_ho_reduce (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "some")])) then (step_ho_some (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "every?")])) then (step_ho_every (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "for-each")])) then (step_ho_for_each (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "raise")])) then (step_sf_raise (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "raise-continuable")])) then (make_cek_state ((first (args))) (env) ((kont_push ((make_raise_eval_frame (env) ((Bool true)))) (kont)))) else (if sx_truthy ((prim_call "=" [_match_val; (String "call/cc")])) then (step_sf_callcc (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "call-with-current-continuation")])) then (step_sf_callcc (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "perform")])) then (step_sf_perform (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "define-library")])) then (step_sf_define_library (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "import")])) then (step_sf_import (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "define-record-type")])) then (make_cek_value ((sf_define_record_type (args) (env))) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "define-protocol")])) then (make_cek_value ((sf_define_protocol (args) (env))) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "implement")])) then (make_cek_value ((sf_implement (args) (env))) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "parameterize")])) then (step_sf_parameterize (args) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "syntax-rules")])) then (make_cek_value ((sf_syntax_rules (args) (env))) (env) (kont)) else (if sx_truthy ((prim_call "=" [_match_val; (String "define-syntax")])) then (step_sf_define (args) (env) (kont)) else (if sx_truthy ((prim_call "has-key?" [custom_special_forms; name])) then (make_cek_value ((cek_call ((get (custom_special_forms) (name))) (List [args; env]))) (env) (kont)) else (if sx_truthy ((let _and = (env_has (env) (name)) in if not (sx_truthy _and) then _and else (is_macro ((env_get (env) (name)))))) then (let mac = (env_get (env) (name)) in (make_cek_state ((expand_macro (mac) (args) (env))) (env) (kont))) else (if sx_truthy ((let _and = render_check in if not (sx_truthy _and) then _and else (cek_call (render_check) (List [expr; env])))) then (make_cek_value ((cek_call (render_fn) (List [expr; env]))) (env) (kont)) else (step_eval_call (head) (args) (env) (kont)))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))) else (step_eval_call (head) (args) (env) (kont)))))
+
+(* kont-extract-provides *)
+and kont_extract_provides kont =
+  (if sx_truthy ((empty_p (kont))) then (List []) else (let frame = (first (kont)) in let rest_frames = (kont_extract_provides ((rest (kont)))) in (if sx_truthy ((prim_call "=" [(frame_type (frame)); (String "provide")])) then (cons ((CekFrame { cf_type = "provide"; cf_env = (get (frame) ((String "env"))); cf_name = (get (frame) ((String "name"))); cf_body = Nil; cf_remaining = (List []); cf_f = Nil; cf_args = Nil; cf_results = (List []); cf_extra = (get (frame) ((String "value"))); cf_extra2 = Nil })) (rest_frames)) else rest_frames)))
+
+(* fire-provide-subscribers *)
+and fire_provide_subscribers frame kont =
+  (let subs = (get (frame) ((String "subscribers"))) in (if sx_truthy ((Bool (not (sx_truthy ((empty_p (subs))))))) then (List.iter (fun sub -> ignore ((cek_call (sub) ((List [kont]))))) (sx_to_list subs); Nil) else Nil))
+
+(* step-sf-bind *)
+and step_sf_bind args env kont =
+  let _bind_tracking_ = _bind_tracking_ref in (let body = (first (args)) in let prev = !_bind_tracking_ref in (let () = ignore ((_bind_tracking_ref := (List []); Nil)) in (make_cek_state (body) (env) ((kont_push ((make_bind_frame (body) (env) (prev))) (kont))))))
 
 (* step-sf-parameterize *)
 and step_sf_parameterize args env kont =
@@ -568,7 +592,7 @@ and sf_syntax_rules args env =
 
 (* step-sf-define-library *)
 and step_sf_define_library args env kont =
-  (let lib_spec = (first (args)) in let decls = (rest (args)) in (let lib_env = (env_extend (env)) in let exports = ref ((List [])) in let body_forms = ref ((List [])) in (let () = ignore ((List.iter (fun decl -> ignore ((if sx_truthy ((let _and = (list_p (decl)) in if not (sx_truthy _and) then _and else (let _and = (Bool (not (sx_truthy ((empty_p (decl)))))) in if not (sx_truthy _and) then _and else (symbol_p ((first (decl))))))) then (let kind = (symbol_name ((first (decl)))) in (if sx_truthy ((prim_call "=" [kind; (String "export")])) then (exports := (prim_call "append" [!exports; (List (List.map (fun s -> (if sx_truthy ((symbol_p (s))) then (symbol_name (s)) else (String (sx_str [s])))) (sx_to_list (rest (decl)))))]); Nil) else (if sx_truthy ((prim_call "=" [kind; (String "begin")])) then (body_forms := (prim_call "append" [!body_forms; (rest (decl))]); Nil) else (if sx_truthy ((prim_call "=" [kind; (String "import")])) then (List.iter (fun import_set -> ignore ((try ignore (eval_expr (List [Symbol "import"; import_set]) (lib_env)) with _ -> ()))) (sx_to_list (rest (decl))); Nil) else Nil)))) else Nil))) (sx_to_list decls); Nil)) in (let () = ignore ((List.iter (fun form -> ignore ((eval_expr (form) (lib_env)))) (sx_to_list !body_forms); Nil)) in (let export_dict = (Dict (Hashtbl.create 0)) in (let () = ignore ((List.iter (fun name -> ignore ((if sx_truthy ((env_has (lib_env) (name))) then (sx_dict_set_b export_dict name (env_get (lib_env) (name))) else Nil))) (sx_to_list !exports); Nil)) in (let () = ignore ((register_library (lib_spec) (export_dict))) in (make_cek_value (Nil) (env) (kont)))))))))
+  (let lib_spec = (first (args)) in let decls = (rest (args)) in (let lib_env = (env_extend (env)) in let exports = ref ((List [])) in let body_forms = ref ((List [])) in (let () = ignore ((List.iter (fun decl -> ignore ((if sx_truthy ((let _and = (list_p (decl)) in if not (sx_truthy _and) then _and else (let _and = (Bool (not (sx_truthy ((empty_p (decl)))))) in if not (sx_truthy _and) then _and else (symbol_p ((first (decl))))))) then (let kind = (symbol_name ((first (decl)))) in (if sx_truthy ((prim_call "=" [kind; (String "export")])) then (exports := (prim_call "append" [!exports; (List (List.map (fun s -> (if sx_truthy ((symbol_p (s))) then (symbol_name (s)) else (String (sx_str [s])))) (sx_to_list (rest (decl)))))]); Nil) else (if sx_truthy ((prim_call "=" [kind; (String "begin")])) then (body_forms := (prim_call "append" [!body_forms; (rest (decl))]); Nil) else Nil))) else Nil))) (sx_to_list decls); Nil)) in (let () = ignore ((List.iter (fun form -> ignore ((eval_expr (form) (lib_env)))) (sx_to_list !body_forms); Nil)) in (let export_dict = (Dict (Hashtbl.create 0)) in (let () = ignore ((List.iter (fun name -> ignore ((if sx_truthy ((env_has (lib_env) (name))) then (sx_dict_set_b export_dict name (env_get (lib_env) (name))) else Nil))) (sx_to_list !exports); Nil)) in (let () = ignore ((register_library (lib_spec) (export_dict))) in (make_cek_value (Nil) (env) (kont)))))))))
 
 (* bind-import-set *)
 and bind_import_set import_set env =
@@ -689,39 +713,19 @@ and step_sf_scope args env kont =
 
 (* step-sf-provide *)
 and step_sf_provide args env kont =
-  (let name = (trampoline ((eval_expr ((first (args))) (env)))) in let val' = (trampoline ((eval_expr ((nth (args) ((Number 1.0)))) (env)))) in let body = (prim_call "slice" [args; (Number 2.0)]) in (if sx_truthy ((empty_p (body))) then (make_cek_value (Nil) (env) (kont)) else (make_cek_state ((first (body))) (env) ((kont_push ((make_provide_frame (name) (val') ((rest (body))) (env))) (kont))))))
+  (let name = (trampoline ((eval_expr ((first (args))) (env)))) in let val' = (trampoline ((eval_expr ((nth (args) ((Number 1.0)))) (env)))) in let body = (prim_call "slice" [args; (Number 2.0)]) in (let () = ignore ((scope_push (name) (val'))) in (if sx_truthy ((empty_p (body))) then (let () = ignore ((scope_pop (name))) in (make_cek_value (Nil) (env) (kont))) else (make_cek_state ((first (body))) (env) ((kont_push ((make_provide_frame (name) (val') ((rest (body))) (env))) (kont)))))))
 
 (* step-sf-context *)
 and step_sf_context args env kont =
-  (let name = (trampoline ((eval_expr ((first (args))) (env)))) in let default_val = (if sx_truthy ((prim_call ">=" [(len (args)); (Number 2.0)])) then (trampoline ((eval_expr ((nth (args) ((Number 1.0)))) (env)))) else Nil) in let frame = (kont_find_provide (kont) (name)) in (make_cek_value ((if sx_truthy (frame) then (get (frame) ((String "value"))) else (if sx_truthy ((env_has (env) ((String "context")))) then (sx_apply (env_get (env) ((String "context"))) (List [name; default_val])) else default_val))) (env) (kont)))
+  let _bind_tracking_ = _bind_tracking_ref in (let name = (trampoline ((eval_expr ((first (args))) (env)))) in let default_val = (if sx_truthy ((prim_call ">=" [(len (args)); (Number 2.0)])) then (trampoline ((eval_expr ((nth (args) ((Number 1.0)))) (env)))) else Nil) in let frame = (kont_find_provide (kont) (name)) in (let () = ignore ((if sx_truthy ((let _and = frame in if not (sx_truthy _and) then _and else !_bind_tracking_ref)) then (if sx_truthy ((Bool (not (sx_truthy ((prim_call "contains?" [!_bind_tracking_ref; frame])))))) then (_bind_tracking_ := sx_append_b !_bind_tracking_ frame; Nil) else Nil) else Nil)) in (make_cek_value ((if sx_truthy (frame) then (get (frame) ((String "value"))) else (let sv = (scope_peek (name)) in (if sx_truthy ((is_nil (sv))) then default_val else sv)))) (env) (kont))))
 
-(* step-sf-peek — non-tracking read from provide frame *)
+(* step-sf-peek *)
 and step_sf_peek args env kont =
-  let name = trampoline (eval_expr (first args) env) in
-  let default_val = if sx_truthy (prim_call ">=" [len args; Number 2.0])
-    then trampoline (eval_expr (nth args (Number 1.0)) env) else Nil in
-  let frame = kont_find_provide kont name in
-  make_cek_value (if sx_truthy frame then get frame (String "value")
-    else if sx_truthy (env_has env (String "peek"))
-    then sx_apply (env_get env (String "peek")) (List [name; default_val])
-    else default_val) env kont
+  (let name = (trampoline ((eval_expr ((first (args))) (env)))) in let default_val = (if sx_truthy ((prim_call ">=" [(len (args)); (Number 2.0)])) then (trampoline ((eval_expr ((nth (args) ((Number 1.0)))) (env)))) else Nil) in let frame = (kont_find_provide (kont) (name)) in (make_cek_value ((if sx_truthy (frame) then (get (frame) ((String "value"))) else (if sx_truthy ((env_has (env) ((String "peek")))) then (sx_apply (env_get (env) ((String "peek"))) (List [name; default_val])) else default_val))) (env) (kont)))
 
-(* step-sf-provide! — mutate value in provide frame *)
+(* step-sf-provide! *)
 and step_sf_provide_b args env kont =
-  let name = trampoline (eval_expr (first args) env) in
-  let new_val = trampoline (eval_expr (nth args (Number 1.0)) env) in
-  let frame = kont_find_provide kont name in
-  if sx_truthy frame then begin
-    (match frame with
-     | CekFrame f -> f.cf_extra <- new_val
-     | Dict d -> Hashtbl.replace d "value" new_val
-     | _ -> ());
-    make_cek_value new_val env kont
-  end else if sx_truthy (env_has env (String "provide-set!"))
-  then begin
-    ignore (sx_apply (env_get env (String "provide-set!")) (List [name; new_val]));
-    make_cek_value new_val env kont
-  end else make_cek_value Nil env kont
+  (let name = (trampoline ((eval_expr ((first (args))) (env)))) in (make_cek_state ((nth (args) ((Number 1.0)))) (env) ((kont_push ((make_provide_set_frame (name) (env))) (kont)))))
 
 (* step-sf-emit *)
 and step_sf_emit args env kont =
@@ -801,7 +805,7 @@ and step_ho_for_each args env kont =
 
 (* step-continue *)
 and step_continue state =
-  let _last_error_kont_ = ref Nil in (let value = (cek_value (state)) in let env = (cek_env (state)) in let kont = (cek_kont (state)) in (if sx_truthy ((kont_empty_p (kont))) then state else (let frame = (kont_top (kont)) in let rest_k = (kont_pop (kont)) in let ft = (frame_type (frame)) in (let _match_val = ft in (if sx_truthy ((prim_call "=" [_match_val; (String "if")])) then (if sx_truthy ((let _and = value in if not (sx_truthy _and) then _and else (Bool (not (sx_truthy ((is_nil (value)))))))) then (make_cek_state ((get (frame) ((String "then")))) ((get (frame) ((String "env")))) (rest_k)) else (if sx_truthy ((is_nil ((get (frame) ((String "else")))))) then (make_cek_value (Nil) (env) (rest_k)) else (make_cek_state ((get (frame) ((String "else")))) ((get (frame) ((String "env")))) (rest_k)))) else (if sx_truthy ((prim_call "=" [_match_val; (String "when")])) then (if sx_truthy ((let _and = value in if not (sx_truthy _and) then _and else (Bool (not (sx_truthy ((is_nil (value)))))))) then (let body = (get (frame) ((String "body"))) in let fenv = (get (frame) ((String "env"))) in (if sx_truthy ((empty_p (body))) then (make_cek_value (Nil) (fenv) (rest_k)) else (if sx_truthy ((prim_call "=" [(len (body)); (Number 1.0)])) then (make_cek_state ((first (body))) (fenv) (rest_k)) else (make_cek_state ((first (body))) (fenv) ((kont_push ((make_begin_frame ((rest (body))) (fenv))) (rest_k))))))) else (make_cek_value (Nil) (env) (rest_k))) else (if sx_truthy ((prim_call "=" [_match_val; (String "begin")])) then (let remaining = (get (frame) ((String "remaining"))) in let fenv = (get (frame) ((String "env"))) in (if sx_truthy ((empty_p (remaining))) then (make_cek_value (value) (fenv) (rest_k)) else (if sx_truthy ((prim_call "=" [(len (remaining)); (Number 1.0)])) then (make_cek_state ((first (remaining))) (fenv) (rest_k)) else (make_cek_state ((first (remaining))) (fenv) ((kont_push ((make_begin_frame ((rest (remaining))) (fenv))) (rest_k))))))) else (if sx_truthy ((prim_call "=" [_match_val; (String "let")])) then (let name = (get (frame) ((String "name"))) in let remaining = (get (frame) ((String "remaining"))) in let body = (get (frame) ((String "body"))) in let local = (get (frame) ((String "env"))) in (let () = ignore ((env_bind local (sx_to_string name) value)) in (if sx_truthy ((empty_p (remaining))) then (step_sf_begin (body) (local) (rest_k)) else (let next_binding = (first (remaining)) in let vname = (if sx_truthy ((prim_call "=" [(type_of ((first (next_binding)))); (String "symbol")])) then (symbol_name ((first (next_binding)))) else (first (next_binding))) in (make_cek_state ((nth (next_binding) ((Number 1.0)))) (local) ((kont_push ((make_let_frame (vname) ((rest (remaining))) (body) (local))) (rest_k)))))))) else (if sx_truthy ((prim_call "=" [_match_val; (String "define")])) then (let name = (get (frame) ((String "name"))) in let fenv = (get (frame) ((String "env"))) in let has_effects = (get (frame) ((String "has-effects"))) in let effect_list = (get (frame) ((String "effect-list"))) in (let () = ignore ((if sx_truthy ((let _and = (is_lambda (value)) in if not (sx_truthy _and) then _and else (is_nil ((lambda_name (value)))))) then (set_lambda_name value (sx_to_string name)) else Nil)) in (let () = ignore ((env_bind fenv (sx_to_string name) value)) in (let () = ignore ((if sx_truthy (has_effects) then (let effect_names = (List (List.map (fun e -> (if sx_truthy ((prim_call "=" [(type_of (e)); (String "symbol")])) then (symbol_name (e)) else e)) (sx_to_list effect_list))) in let effect_anns = (if sx_truthy ((env_has (fenv) ((String "*effect-annotations*")))) then (env_get (fenv) ((String "*effect-annotations*"))) else (Dict (Hashtbl.create 0))) in (let () = ignore ((sx_dict_set_b effect_anns name effect_names)) in (env_bind fenv (sx_to_string (String "*effect-annotations*")) effect_anns))) else Nil)) in (make_cek_value (value) (fenv) (rest_k)))))) else (if sx_truthy ((prim_call "=" [_match_val; (String "set")])) then (let name = (get (frame) ((String "name"))) in let fenv = (get (frame) ((String "env"))) in (let () = ignore ((env_set fenv (sx_to_string name) value)) in (make_cek_value (value) (env) (rest_k)))) else (if sx_truthy ((prim_call "=" [_match_val; (String "and")])) then (if sx_truthy ((Bool (not (sx_truthy (value))))) then (make_cek_value (value) (env) (rest_k)) else (let remaining = (get (frame) ((String "remaining"))) in (if sx_truthy ((empty_p (remaining))) then (make_cek_value (value) (env) (rest_k)) else (make_cek_state ((first (remaining))) ((get (frame) ((String "env")))) ((if sx_truthy ((prim_call "=" [(len (remaining)); (Number 1.0)])) then rest_k else (kont_push ((make_and_frame ((rest (remaining))) ((get (frame) ((String "env")))))) (rest_k)))))))) else (if sx_truthy ((prim_call "=" [_match_val; (String "or")])) then (if sx_truthy (value) then (make_cek_value (value) (env) (rest_k)) else (let remaining = (get (frame) ((String "remaining"))) in (if sx_truthy ((empty_p (remaining))) then (make_cek_value ((Bool false)) (env) (rest_k)) else (make_cek_state ((first (remaining))) ((get (frame) ((String "env")))) ((if sx_truthy ((prim_call "=" [(len (remaining)); (Number 1.0)])) then rest_k else (kont_push ((make_or_frame ((rest (remaining))) ((get (frame) ((String "env")))))) (rest_k)))))))) else (if sx_truthy ((prim_call "=" [_match_val; (String "cond")])) then (let remaining = (get (frame) ((String "remaining"))) in let fenv = (get (frame) ((String "env"))) in let scheme_p = (get (frame) ((String "scheme"))) in (if sx_truthy (scheme_p) then (if sx_truthy (value) then (let clause = (first (remaining)) in (if sx_truthy ((let _and = (prim_call ">" [(len (clause)); (Number 2.0)]) in if not (sx_truthy _and) then _and else (let _and = (prim_call "=" [(type_of ((nth (clause) ((Number 1.0))))); (String "symbol")]) in if not (sx_truthy _and) then _and else (prim_call "=" [(symbol_name ((nth (clause) ((Number 1.0))))); (String "=>")])))) then (make_cek_state ((nth (clause) ((Number 2.0)))) (fenv) ((kont_push ((make_cond_arrow_frame (value) (fenv))) (rest_k)))) else (make_cek_state ((nth (clause) ((Number 1.0)))) (fenv) (rest_k)))) else (let next_clauses = (rest (remaining)) in (if sx_truthy ((empty_p (next_clauses))) then (make_cek_value (Nil) (fenv) (rest_k)) else (let next_clause = (first (next_clauses)) in let next_test = (first (next_clause)) in (if sx_truthy ((is_else_clause (next_test))) then (make_cek_state ((nth (next_clause) ((Number 1.0)))) (fenv) (rest_k)) else (make_cek_state (next_test) (fenv) ((kont_push ((make_cond_frame (next_clauses) (fenv) ((Bool true)))) (rest_k))))))))) else (if sx_truthy (value) then (make_cek_state ((nth (remaining) ((Number 1.0)))) (fenv) (rest_k)) else (let next = (prim_call "slice" [remaining; (Number 2.0); (len (remaining))]) in (if sx_truthy ((prim_call "<" [(len (next)); (Number 2.0)])) then (make_cek_value (Nil) (fenv) (rest_k)) else (let next_test = (first (next)) in (if sx_truthy ((is_else_clause (next_test))) then (make_cek_state ((nth (next) ((Number 1.0)))) (fenv) (rest_k)) else (make_cek_state (next_test) (fenv) ((kont_push ((make_cond_frame (next) (fenv) ((Bool false)))) (rest_k))))))))))) else (if sx_truthy ((prim_call "=" [_match_val; (String "case")])) then (let match_val = (get (frame) ((String "match-val"))) in let remaining = (get (frame) ((String "remaining"))) in let fenv = (get (frame) ((String "env"))) in (if sx_truthy ((is_nil (match_val))) then (sf_case_step_loop (value) (remaining) (fenv) (rest_k)) else (sf_case_step_loop (match_val) (remaining) (fenv) (rest_k)))) else (if sx_truthy ((prim_call "=" [_match_val; (String "thread")])) then (let remaining = (get (frame) ((String "remaining"))) in let fenv = (get (frame) ((String "env"))) in let mode = (get (frame) ((String "extra"))) in let bind_name = (get (frame) ((String "name"))) in (if sx_truthy ((empty_p (remaining))) then (make_cek_value (value) (fenv) (rest_k)) else (let form = (first (remaining)) in let rest_forms = (rest (remaining)) in let new_kont = (if sx_truthy ((empty_p ((rest (remaining))))) then rest_k else (kont_push ((make_thread_frame ((rest (remaining))) (fenv) (mode) (bind_name))) (rest_k))) in (if sx_truthy ((prim_call "=" [mode; (String "as")])) then (let new_env = (env_extend (fenv)) in (let () = ignore ((env_bind new_env (sx_to_string (symbol_name (bind_name))) value)) in (make_cek_state (form) (new_env) (new_kont)))) else (if sx_truthy ((let _and = (prim_call "=" [(type_of (form)); (String "list")]) in if not (sx_truthy _and) then _and else (let _and = (Bool (not (sx_truthy ((empty_p (form)))))) in if not (sx_truthy _and) then _and else (let _and = (prim_call "=" [(type_of ((first (form)))); (String "symbol")]) in if not (sx_truthy _and) then _and else (ho_form_name_p ((symbol_name ((first (form)))))))))) then (make_cek_state ((cons ((first (form))) ((cons ((List [(Symbol "quote"); value])) ((rest (form))))))) (fenv) (new_kont)) else (if sx_truthy ((prim_call "=" [mode; (String "last")])) then (let result' = (thread_insert_arg_last (form) (value) (fenv)) in (if sx_truthy ((empty_p (rest_forms))) then (make_cek_value (result') (fenv) (rest_k)) else (make_cek_value (result') (fenv) ((kont_push ((make_thread_frame (rest_forms) (fenv) (mode) (bind_name))) (rest_k)))))) else (let result' = (thread_insert_arg (form) (value) (fenv)) in (if sx_truthy ((empty_p (rest_forms))) then (make_cek_value (result') (fenv) (rest_k)) else (make_cek_value (result') (fenv) ((kont_push ((make_thread_frame (rest_forms) (fenv) (mode) (bind_name))) (rest_k)))))))))))) else (if sx_truthy ((prim_call "=" [_match_val; (String "arg")])) then (let f = (get (frame) ((String "f"))) in let evaled = (get (frame) ((String "evaled"))) in let remaining = (get (frame) ((String "remaining"))) in let fenv = (get (frame) ((String "env"))) in let raw_args = (get (frame) ((String "raw-args"))) in let hname = (get (frame) ((String "head-name"))) in (if sx_truthy ((is_nil (f))) then (let () = ignore ((if sx_truthy ((let _and = !_strict_ref in if not (sx_truthy _and) then _and else hname)) then (strict_check_args (hname) ((List []))) else Nil)) in (if sx_truthy ((empty_p (remaining))) then (continue_with_call (value) ((List [])) (fenv) (raw_args) (rest_k)) else (make_cek_state ((first (remaining))) (fenv) ((kont_push ((make_arg_frame (value) ((List [])) ((rest (remaining))) (fenv) (raw_args) (hname))) (rest_k)))))) else (let new_evaled = (prim_call "append" [evaled; (List [value])]) in (if sx_truthy ((empty_p (remaining))) then (let () = ignore ((if sx_truthy ((let _and = !_strict_ref in if not (sx_truthy _and) then _and else hname)) then (strict_check_args (hname) (new_evaled)) else Nil)) in (continue_with_call (f) (new_evaled) (fenv) (raw_args) (rest_k))) else (make_cek_state ((first (remaining))) (fenv) ((kont_push ((make_arg_frame (f) (new_evaled) ((rest (remaining))) (fenv) (raw_args) (hname))) (rest_k)))))))) else (if sx_truthy ((prim_call "=" [_match_val; (String "dict")])) then (let remaining = (get (frame) ((String "remaining"))) in let results = (get (frame) ((String "results"))) in let fenv = (get (frame) ((String "env"))) in (let last_result = (last (results)) in let completed = (prim_call "append" [(prim_call "slice" [results; (Number 0.0); (prim_call "dec" [(len (results))])]); (List [(List [(first (last_result)); value])])]) in (if sx_truthy ((empty_p (remaining))) then (let d = (Dict (Hashtbl.create 0)) in (let () = ignore ((List.iter (fun pair -> ignore ((sx_dict_set_b d (first (pair)) (nth (pair) ((Number 1.0)))))) (sx_to_list completed); Nil)) in (make_cek_value (d) (fenv) (rest_k)))) else (let next_entry = (first (remaining)) in (make_cek_state ((nth (next_entry) ((Number 1.0)))) (fenv) ((kont_push ((make_dict_frame ((rest (remaining))) ((prim_call "append" [completed; (List [(List [(first (next_entry))])])])) (fenv))) (rest_k)))))))) else (if sx_truthy ((prim_call "=" [_match_val; (String "ho-setup")])) then (let ho_type = (get (frame) ((String "ho-type"))) in let remaining = (get (frame) ((String "remaining"))) in let evaled = (prim_call "append" [(get (frame) ((String "evaled"))); (List [value])]) in let fenv = (get (frame) ((String "env"))) in (if sx_truthy ((empty_p (remaining))) then (ho_setup_dispatch (ho_type) (evaled) (fenv) (rest_k)) else (make_cek_state ((first (remaining))) (fenv) ((kont_push ((make_ho_setup_frame (ho_type) ((rest (remaining))) (evaled) (fenv))) (rest_k)))))) else (if sx_truthy ((prim_call "=" [_match_val; (String "reset")])) then (make_cek_value (value) (env) (rest_k)) else (if sx_truthy ((prim_call "=" [_match_val; (String "deref")])) then (let val' = value in let fenv = (get (frame) ((String "env"))) in (if sx_truthy ((Bool (not (sx_truthy ((is_signal (val'))))))) then (make_cek_value (val') (fenv) (rest_k)) else (if sx_truthy ((has_reactive_reset_frame_p (rest_k))) then (reactive_shift_deref (val') (fenv) (rest_k)) else (let () = ignore ((let ctx = (sx_context ((String "sx-reactive")) (Nil)) in (if sx_truthy (ctx) then (let dep_list = ref ((get (ctx) ((String "deps")))) in let notify_fn = (get (ctx) ((String "notify"))) in (if sx_truthy ((Bool (not (sx_truthy ((prim_call "contains?" [!dep_list; val'])))))) then (let () = ignore ((dep_list := sx_append_b !dep_list val'; Nil)) in (signal_add_sub_b (val') (notify_fn))) else Nil)) else Nil))) in (make_cek_value ((signal_value (val'))) (fenv) (rest_k)))))) else (if sx_truthy ((prim_call "=" [_match_val; (String "reactive-reset")])) then (let update_fn = (get (frame) ((String "update-fn"))) in let first_p = (get (frame) ((String "first-render"))) in (let () = ignore ((if sx_truthy ((let _and = update_fn in if not (sx_truthy _and) then _and else (Bool (not (sx_truthy (first_p)))))) then (cek_call (update_fn) ((List [value]))) else Nil)) in (make_cek_value (value) (env) (rest_k)))) else (if sx_truthy ((prim_call "=" [_match_val; (String "scope")])) then (let name = (get (frame) ((String "name"))) in let remaining = (get (frame) ((String "remaining"))) in let fenv = (get (frame) ((String "env"))) in (if sx_truthy ((empty_p (remaining))) then (let () = ignore ((scope_pop (name))) in (make_cek_value (value) (fenv) (rest_k))) else (make_cek_state ((first (remaining))) (fenv) ((kont_push ((make_scope_frame (name) ((rest (remaining))) (fenv))) (rest_k)))))) else (if sx_truthy ((prim_call "=" [_match_val; (String "provide")])) then (let remaining = (get (frame) ((String "remaining"))) in let fenv = (get (frame) ((String "env"))) in (if sx_truthy ((empty_p (remaining))) then (make_cek_value (value) (fenv) (rest_k)) else (make_cek_state ((first (remaining))) (fenv) ((kont_push ((make_provide_frame ((get (frame) ((String "name")))) ((get (frame) ((String "value")))) ((rest (remaining))) (fenv))) (rest_k)))))) else (if sx_truthy ((prim_call "=" [_match_val; (String "scope-acc")])) then (let remaining = (get (frame) ((String "remaining"))) in let fenv = (get (frame) ((String "env"))) in (if sx_truthy ((empty_p (remaining))) then (make_cek_value (value) (fenv) (rest_k)) else (make_cek_state ((first (remaining))) (fenv) ((kont_push ((let new_frame = (make_scope_acc_frame ((get (frame) ((String "name")))) ((get (frame) ((String "value")))) ((rest (remaining))) (fenv)) in (let () = ignore ((sx_dict_set_b new_frame (String "emitted") (get (frame) ((String "emitted"))))) in new_frame))) (rest_k)))))) else (if sx_truthy ((prim_call "=" [_match_val; (String "map")])) then (let f = (get (frame) ((String "f"))) in let remaining = (get (frame) ((String "remaining"))) in let results = (get (frame) ((String "results"))) in let indexed = (get (frame) ((String "indexed"))) in let fenv = (get (frame) ((String "env"))) in (let new_results = (prim_call "append" [results; (List [value])]) in (if sx_truthy ((empty_p (remaining))) then (make_cek_value (new_results) (fenv) (rest_k)) else (let call_args = (if sx_truthy (indexed) then (List [(len (new_results)); (first (remaining))]) else (List [(first (remaining))])) in let next_frame = (if sx_truthy (indexed) then (make_map_indexed_frame (f) ((rest (remaining))) (new_results) (fenv)) else (make_map_frame (f) ((rest (remaining))) (new_results) (fenv))) in (continue_with_call (f) (call_args) (fenv) ((List [])) ((kont_push (next_frame) (rest_k)))))))) else (if sx_truthy ((prim_call "=" [_match_val; (String "filter")])) then (let f = (get (frame) ((String "f"))) in let remaining = (get (frame) ((String "remaining"))) in let results = (get (frame) ((String "results"))) in let current_item = (get (frame) ((String "current-item"))) in let fenv = (get (frame) ((String "env"))) in (let new_results = (if sx_truthy (value) then (prim_call "append" [results; (List [current_item])]) else results) in (if sx_truthy ((empty_p (remaining))) then (make_cek_value (new_results) (fenv) (rest_k)) else (continue_with_call (f) ((List [(first (remaining))])) (fenv) ((List [])) ((kont_push ((make_filter_frame (f) ((rest (remaining))) (new_results) ((first (remaining))) (fenv))) (rest_k))))))) else (if sx_truthy ((prim_call "=" [_match_val; (String "reduce")])) then (let f = (get (frame) ((String "f"))) in let remaining = (get (frame) ((String "remaining"))) in let fenv = (get (frame) ((String "env"))) in (if sx_truthy ((empty_p (remaining))) then (make_cek_value (value) (fenv) (rest_k)) else (continue_with_call (f) ((List [value; (first (remaining))])) (fenv) ((List [])) ((kont_push ((make_reduce_frame (f) ((rest (remaining))) (fenv))) (rest_k)))))) else (if sx_truthy ((prim_call "=" [_match_val; (String "for-each")])) then (let f = (get (frame) ((String "f"))) in let remaining = (get (frame) ((String "remaining"))) in let fenv = (get (frame) ((String "env"))) in (if sx_truthy ((empty_p (remaining))) then (make_cek_value (Nil) (fenv) (rest_k)) else (continue_with_call (f) ((List [(first (remaining))])) (fenv) ((List [])) ((kont_push ((make_for_each_frame (f) ((rest (remaining))) (fenv))) (rest_k)))))) else (if sx_truthy ((prim_call "=" [_match_val; (String "some")])) then (let f = (get (frame) ((String "f"))) in let remaining = (get (frame) ((String "remaining"))) in let fenv = (get (frame) ((String "env"))) in (if sx_truthy (value) then (make_cek_value (value) (fenv) (rest_k)) else (if sx_truthy ((empty_p (remaining))) then (make_cek_value ((Bool false)) (fenv) (rest_k)) else (continue_with_call (f) ((List [(first (remaining))])) (fenv) ((List [])) ((kont_push ((make_some_frame (f) ((rest (remaining))) (fenv))) (rest_k))))))) else (if sx_truthy ((prim_call "=" [_match_val; (String "every")])) then (let f = (get (frame) ((String "f"))) in let remaining = (get (frame) ((String "remaining"))) in let fenv = (get (frame) ((String "env"))) in (if sx_truthy ((Bool (not (sx_truthy (value))))) then (make_cek_value ((Bool false)) (fenv) (rest_k)) else (if sx_truthy ((empty_p (remaining))) then (make_cek_value ((Bool true)) (fenv) (rest_k)) else (continue_with_call (f) ((List [(first (remaining))])) (fenv) ((List [])) ((kont_push ((make_every_frame (f) ((rest (remaining))) (fenv))) (rest_k))))))) else (if sx_truthy ((prim_call "=" [_match_val; (String "handler")])) then (let remaining = (get (frame) ((String "remaining"))) in let fenv = (get (frame) ((String "env"))) in (if sx_truthy ((empty_p (remaining))) then (make_cek_value (value) (fenv) (rest_k)) else (make_cek_state ((first (remaining))) (fenv) ((kont_push ((make_handler_frame ((get (frame) ((String "f")))) ((rest (remaining))) (fenv))) (rest_k)))))) else (if sx_truthy ((prim_call "=" [_match_val; (String "restart")])) then (make_cek_value (value) (env) (rest_k)) else (if sx_truthy ((prim_call "=" [_match_val; (String "signal-return")])) then (let saved_kont = (get (frame) ((String "saved-kont"))) in (make_cek_value (value) ((get (frame) ((String "env")))) (saved_kont))) else (if sx_truthy ((prim_call "=" [_match_val; (String "comp-trace")])) then (make_cek_value (value) (env) (rest_k)) else (if sx_truthy ((prim_call "=" [_match_val; (String "cond-arrow")])) then (let test_value = (get (frame) ((String "match-val"))) in let fenv = (get (frame) ((String "env"))) in (continue_with_call (value) ((List [test_value])) (fenv) ((List [test_value])) (rest_k))) else (if sx_truthy ((prim_call "=" [_match_val; (String "raise-eval")])) then (let condition = value in let fenv = (get (frame) ((String "env"))) in let continuable_p = (get (frame) ((String "scheme"))) in let handler_fn = (kont_find_handler (rest_k) (condition)) in (if sx_truthy ((is_nil (handler_fn))) then (let () = ignore ((_last_error_kont_ref := rest_k; Nil)) in (host_error ((String (sx_str [(String "Unhandled exception: "); (inspect (condition))]))))) else (continue_with_call (handler_fn) ((List [condition])) (fenv) ((List [condition])) ((if sx_truthy (continuable_p) then (kont_push ((make_signal_return_frame (fenv) (rest_k))) (rest_k)) else (kont_push ((make_raise_guard_frame (fenv) (rest_k))) (rest_k))))))) else (if sx_truthy ((prim_call "=" [_match_val; (String "raise-guard")])) then (let () = ignore ((_last_error_kont_ref := rest_k; Nil)) in (host_error ((String "exception handler returned from non-continuable raise")))) else (if sx_truthy ((prim_call "=" [_match_val; (String "multi-map")])) then (let f = (get (frame) ((String "f"))) in let remaining = (get (frame) ((String "remaining"))) in let new_results = (prim_call "append" [(get (frame) ((String "results"))); (List [value])]) in let fenv = (get (frame) ((String "env"))) in (if sx_truthy ((Bool (List.exists (fun c -> sx_truthy ((empty_p (c)))) (sx_to_list remaining)))) then (make_cek_value (new_results) (fenv) (rest_k)) else (let heads = (List (List.map (fun c -> (first (c))) (sx_to_list remaining))) in let tails = (List (List.map (fun c -> (rest (c))) (sx_to_list remaining))) in (continue_with_call (f) (heads) (fenv) ((List [])) ((kont_push ((make_multi_map_frame (f) (tails) (new_results) (fenv))) (rest_k))))))) else (if sx_truthy ((prim_call "=" [_match_val; (String "callcc")])) then (let k = (make_callcc_continuation (rest_k)) in (continue_with_call (value) ((List [k])) ((get (frame) ((String "env")))) ((List [k])) (rest_k))) else (if sx_truthy ((prim_call "=" [_match_val; (String "vm-resume")])) then (let resume_fn = (get (frame) ((String "f"))) in (let result' = (sx_apply resume_fn (List [value])) in (if sx_truthy ((let _and = (dict_p (result')) in if not (sx_truthy _and) then _and else (get (result') ((String "__vm_suspended"))))) then (make_cek_suspended ((get (result') ((String "request")))) ((get (frame) ((String "env")))) ((kont_push ((make_vm_resume_frame ((get (result') ((String "resume")))) ((get (frame) ((String "env")))))) (rest_k)))) else (make_cek_value (result') ((get (frame) ((String "env")))) (rest_k))))) else (if sx_truthy ((prim_call "=" [_match_val; (String "perform")])) then (make_cek_suspended (value) ((get (frame) ((String "env")))) (rest_k)) else (if sx_truthy ((prim_call "=" [_match_val; (String "import")])) then (let import_set = (get (frame) ((String "args"))) in let remaining_sets = (get (frame) ((String "remaining"))) in let fenv = (get (frame) ((String "env"))) in (let () = ignore ((bind_import_set (import_set) (fenv))) in (if sx_truthy ((empty_p (remaining_sets))) then (make_cek_value (Nil) (fenv) (rest_k)) else (step_sf_import (remaining_sets) (fenv) (rest_k))))) else (if sx_truthy ((prim_call "=" [_match_val; (String "parameterize")])) then (let remaining = (get (frame) ((String "remaining"))) in let current_param = (get (frame) ((String "f"))) in let results = (get (frame) ((String "results"))) in let body = (get (frame) ((String "body"))) in let fenv = (get (frame) ((String "env"))) in (if sx_truthy ((is_nil (current_param))) then (let param_obj = value in let val_expr = (nth ((first (remaining))) ((Number 1.0))) in (make_cek_state (val_expr) (fenv) ((kont_push ((make_parameterize_frame (remaining) (param_obj) (results) (body) (fenv))) (rest_k))))) else (let converted_val = value in let new_results = (prim_call "append" [results; (List [(List [(parameter_uid (current_param)); converted_val])])]) in let rest_bindings = (rest (remaining)) in (if sx_truthy ((empty_p (rest_bindings))) then (let body_expr = (if sx_truthy ((prim_call "=" [(len (body)); (Number 1.0)])) then (first (body)) else (cons ((Symbol "begin")) (body))) in let provide_kont = (kont_push_provides (new_results) (fenv) (rest_k)) in (make_cek_state (body_expr) (fenv) (provide_kont))) else (make_cek_state ((first ((first (rest_bindings))))) (fenv) ((kont_push ((make_parameterize_frame (rest_bindings) (Nil) (new_results) (body) (fenv))) (rest_k)))))))) else (let () = ignore ((_last_error_kont_ref := rest_k; Nil)) in (raise (Eval_error (value_to_str (String (sx_str [(String "Unknown frame type: "); ft])))))))))))))))))))))))))))))))))))))))))))))))))
+  let _bind_tracking_ = _bind_tracking_ref in let _last_error_kont_ = ref Nil in (let value = (cek_value (state)) in let env = (cek_env (state)) in let kont = (cek_kont (state)) in (if sx_truthy ((kont_empty_p (kont))) then state else (let frame = (kont_top (kont)) in let rest_k = (kont_pop (kont)) in let ft = (frame_type (frame)) in (let _match_val = ft in (if sx_truthy ((prim_call "=" [_match_val; (String "if")])) then (if sx_truthy ((let _and = value in if not (sx_truthy _and) then _and else (Bool (not (sx_truthy ((is_nil (value)))))))) then (make_cek_state ((get (frame) ((String "then")))) ((get (frame) ((String "env")))) (rest_k)) else (if sx_truthy ((is_nil ((get (frame) ((String "else")))))) then (make_cek_value (Nil) (env) (rest_k)) else (make_cek_state ((get (frame) ((String "else")))) ((get (frame) ((String "env")))) (rest_k)))) else (if sx_truthy ((prim_call "=" [_match_val; (String "when")])) then (if sx_truthy ((let _and = value in if not (sx_truthy _and) then _and else (Bool (not (sx_truthy ((is_nil (value)))))))) then (let body = (get (frame) ((String "body"))) in let fenv = (get (frame) ((String "env"))) in (if sx_truthy ((empty_p (body))) then (make_cek_value (Nil) (fenv) (rest_k)) else (if sx_truthy ((prim_call "=" [(len (body)); (Number 1.0)])) then (make_cek_state ((first (body))) (fenv) (rest_k)) else (make_cek_state ((first (body))) (fenv) ((kont_push ((make_begin_frame ((rest (body))) (fenv))) (rest_k))))))) else (make_cek_value (Nil) (env) (rest_k))) else (if sx_truthy ((prim_call "=" [_match_val; (String "begin")])) then (let remaining = (get (frame) ((String "remaining"))) in let fenv = (get (frame) ((String "env"))) in (if sx_truthy ((empty_p (remaining))) then (make_cek_value (value) (fenv) (rest_k)) else (if sx_truthy ((prim_call "=" [(len (remaining)); (Number 1.0)])) then (make_cek_state ((first (remaining))) (fenv) (rest_k)) else (make_cek_state ((first (remaining))) (fenv) ((kont_push ((make_begin_frame ((rest (remaining))) (fenv))) (rest_k))))))) else (if sx_truthy ((prim_call "=" [_match_val; (String "let")])) then (let name = (get (frame) ((String "name"))) in let remaining = (get (frame) ((String "remaining"))) in let body = (get (frame) ((String "body"))) in let local = (get (frame) ((String "env"))) in (let () = ignore ((env_bind local (sx_to_string name) value)) in (if sx_truthy ((empty_p (remaining))) then (step_sf_begin (body) (local) (rest_k)) else (let next_binding = (first (remaining)) in let vname = (if sx_truthy ((prim_call "=" [(type_of ((first (next_binding)))); (String "symbol")])) then (symbol_name ((first (next_binding)))) else (first (next_binding))) in (make_cek_state ((nth (next_binding) ((Number 1.0)))) (local) ((kont_push ((make_let_frame (vname) ((rest (remaining))) (body) (local))) (rest_k)))))))) else (if sx_truthy ((prim_call "=" [_match_val; (String "define")])) then (let name = (get (frame) ((String "name"))) in let fenv = (get (frame) ((String "env"))) in let has_effects = (get (frame) ((String "has-effects"))) in let effect_list = (get (frame) ((String "effect-list"))) in (let () = ignore ((if sx_truthy ((let _and = (is_lambda (value)) in if not (sx_truthy _and) then _and else (is_nil ((lambda_name (value)))))) then (set_lambda_name value (sx_to_string name)) else Nil)) in (let () = ignore ((env_bind fenv (sx_to_string name) value)) in (let () = ignore ((if sx_truthy (has_effects) then (let effect_names = (List (List.map (fun e -> (if sx_truthy ((prim_call "=" [(type_of (e)); (String "symbol")])) then (symbol_name (e)) else e)) (sx_to_list effect_list))) in let effect_anns = (if sx_truthy ((env_has (fenv) ((String "*effect-annotations*")))) then (env_get (fenv) ((String "*effect-annotations*"))) else (Dict (Hashtbl.create 0))) in (let () = ignore ((sx_dict_set_b effect_anns name effect_names)) in (env_bind fenv (sx_to_string (String "*effect-annotations*")) effect_anns))) else Nil)) in (make_cek_value (value) (fenv) (rest_k)))))) else (if sx_truthy ((prim_call "=" [_match_val; (String "set")])) then (let name = (get (frame) ((String "name"))) in let fenv = (get (frame) ((String "env"))) in (let () = ignore ((env_set fenv (sx_to_string name) value)) in (make_cek_value (value) (env) (rest_k)))) else (if sx_truthy ((prim_call "=" [_match_val; (String "and")])) then (if sx_truthy ((Bool (not (sx_truthy (value))))) then (make_cek_value (value) (env) (rest_k)) else (let remaining = (get (frame) ((String "remaining"))) in (if sx_truthy ((empty_p (remaining))) then (make_cek_value (value) (env) (rest_k)) else (make_cek_state ((first (remaining))) ((get (frame) ((String "env")))) ((if sx_truthy ((prim_call "=" [(len (remaining)); (Number 1.0)])) then rest_k else (kont_push ((make_and_frame ((rest (remaining))) ((get (frame) ((String "env")))))) (rest_k)))))))) else (if sx_truthy ((prim_call "=" [_match_val; (String "or")])) then (if sx_truthy (value) then (make_cek_value (value) (env) (rest_k)) else (let remaining = (get (frame) ((String "remaining"))) in (if sx_truthy ((empty_p (remaining))) then (make_cek_value ((Bool false)) (env) (rest_k)) else (make_cek_state ((first (remaining))) ((get (frame) ((String "env")))) ((if sx_truthy ((prim_call "=" [(len (remaining)); (Number 1.0)])) then rest_k else (kont_push ((make_or_frame ((rest (remaining))) ((get (frame) ((String "env")))))) (rest_k)))))))) else (if sx_truthy ((prim_call "=" [_match_val; (String "cond")])) then (let remaining = (get (frame) ((String "remaining"))) in let fenv = (get (frame) ((String "env"))) in let scheme_p = (get (frame) ((String "scheme"))) in (if sx_truthy (scheme_p) then (if sx_truthy (value) then (let clause = (first (remaining)) in (if sx_truthy ((let _and = (prim_call ">" [(len (clause)); (Number 2.0)]) in if not (sx_truthy _and) then _and else (let _and = (prim_call "=" [(type_of ((nth (clause) ((Number 1.0))))); (String "symbol")]) in if not (sx_truthy _and) then _and else (prim_call "=" [(symbol_name ((nth (clause) ((Number 1.0))))); (String "=>")])))) then (make_cek_state ((nth (clause) ((Number 2.0)))) (fenv) ((kont_push ((make_cond_arrow_frame (value) (fenv))) (rest_k)))) else (make_cek_state ((nth (clause) ((Number 1.0)))) (fenv) (rest_k)))) else (let next_clauses = (rest (remaining)) in (if sx_truthy ((empty_p (next_clauses))) then (make_cek_value (Nil) (fenv) (rest_k)) else (let next_clause = (first (next_clauses)) in let next_test = (first (next_clause)) in (if sx_truthy ((is_else_clause (next_test))) then (make_cek_state ((nth (next_clause) ((Number 1.0)))) (fenv) (rest_k)) else (make_cek_state (next_test) (fenv) ((kont_push ((make_cond_frame (next_clauses) (fenv) ((Bool true)))) (rest_k))))))))) else (if sx_truthy (value) then (make_cek_state ((nth (remaining) ((Number 1.0)))) (fenv) (rest_k)) else (let next = (prim_call "slice" [remaining; (Number 2.0); (len (remaining))]) in (if sx_truthy ((prim_call "<" [(len (next)); (Number 2.0)])) then (make_cek_value (Nil) (fenv) (rest_k)) else (let next_test = (first (next)) in (if sx_truthy ((is_else_clause (next_test))) then (make_cek_state ((nth (next) ((Number 1.0)))) (fenv) (rest_k)) else (make_cek_state (next_test) (fenv) ((kont_push ((make_cond_frame (next) (fenv) ((Bool false)))) (rest_k))))))))))) else (if sx_truthy ((prim_call "=" [_match_val; (String "case")])) then (let match_val = (get (frame) ((String "match-val"))) in let remaining = (get (frame) ((String "remaining"))) in let fenv = (get (frame) ((String "env"))) in (if sx_truthy ((is_nil (match_val))) then (sf_case_step_loop (value) (remaining) (fenv) (rest_k)) else (sf_case_step_loop (match_val) (remaining) (fenv) (rest_k)))) else (if sx_truthy ((prim_call "=" [_match_val; (String "thread")])) then (let remaining = (get (frame) ((String "remaining"))) in let fenv = (get (frame) ((String "env"))) in let mode = (get (frame) ((String "extra"))) in let bind_name = (get (frame) ((String "name"))) in (if sx_truthy ((empty_p (remaining))) then (make_cek_value (value) (fenv) (rest_k)) else (let form = (first (remaining)) in let rest_forms = (rest (remaining)) in let new_kont = (if sx_truthy ((empty_p ((rest (remaining))))) then rest_k else (kont_push ((make_thread_frame ((rest (remaining))) (fenv) (mode) (bind_name))) (rest_k))) in (if sx_truthy ((prim_call "=" [mode; (String "as")])) then (let new_env = (env_extend (fenv)) in (let () = ignore ((env_bind new_env (sx_to_string (symbol_name (bind_name))) value)) in (make_cek_state (form) (new_env) (new_kont)))) else (if sx_truthy ((let _and = (prim_call "=" [(type_of (form)); (String "list")]) in if not (sx_truthy _and) then _and else (let _and = (Bool (not (sx_truthy ((empty_p (form)))))) in if not (sx_truthy _and) then _and else (let _and = (prim_call "=" [(type_of ((first (form)))); (String "symbol")]) in if not (sx_truthy _and) then _and else (ho_form_name_p ((symbol_name ((first (form)))))))))) then (make_cek_state ((cons ((first (form))) ((cons ((List [(Symbol "quote"); value])) ((rest (form))))))) (fenv) (new_kont)) else (if sx_truthy ((prim_call "=" [mode; (String "last")])) then (let result' = (thread_insert_arg_last (form) (value) (fenv)) in (if sx_truthy ((empty_p (rest_forms))) then (make_cek_value (result') (fenv) (rest_k)) else (make_cek_value (result') (fenv) ((kont_push ((make_thread_frame (rest_forms) (fenv) (mode) (bind_name))) (rest_k)))))) else (let result' = (thread_insert_arg (form) (value) (fenv)) in (if sx_truthy ((empty_p (rest_forms))) then (make_cek_value (result') (fenv) (rest_k)) else (make_cek_value (result') (fenv) ((kont_push ((make_thread_frame (rest_forms) (fenv) (mode) (bind_name))) (rest_k)))))))))))) else (if sx_truthy ((prim_call "=" [_match_val; (String "arg")])) then (let f = (get (frame) ((String "f"))) in let evaled = (get (frame) ((String "evaled"))) in let remaining = (get (frame) ((String "remaining"))) in let fenv = (get (frame) ((String "env"))) in let raw_args = (get (frame) ((String "raw-args"))) in let hname = (get (frame) ((String "head-name"))) in (if sx_truthy ((is_nil (f))) then (let () = ignore ((if sx_truthy ((let _and = !_strict_ref in if not (sx_truthy _and) then _and else hname)) then (strict_check_args (hname) ((List []))) else Nil)) in (if sx_truthy ((empty_p (remaining))) then (continue_with_call (value) ((List [])) (fenv) (raw_args) (rest_k)) else (make_cek_state ((first (remaining))) (fenv) ((kont_push ((make_arg_frame (value) ((List [])) ((rest (remaining))) (fenv) (raw_args) (hname))) (rest_k)))))) else (let new_evaled = (prim_call "append" [evaled; (List [value])]) in (if sx_truthy ((empty_p (remaining))) then (let () = ignore ((if sx_truthy ((let _and = !_strict_ref in if not (sx_truthy _and) then _and else hname)) then (strict_check_args (hname) (new_evaled)) else Nil)) in (continue_with_call (f) (new_evaled) (fenv) (raw_args) (rest_k))) else (make_cek_state ((first (remaining))) (fenv) ((kont_push ((make_arg_frame (f) (new_evaled) ((rest (remaining))) (fenv) (raw_args) (hname))) (rest_k)))))))) else (if sx_truthy ((prim_call "=" [_match_val; (String "dict")])) then (let remaining = (get (frame) ((String "remaining"))) in let results = (get (frame) ((String "results"))) in let fenv = (get (frame) ((String "env"))) in (let last_result = (last (results)) in let completed = (prim_call "append" [(prim_call "slice" [results; (Number 0.0); (prim_call "dec" [(len (results))])]); (List [(List [(first (last_result)); value])])]) in (if sx_truthy ((empty_p (remaining))) then (let d = (Dict (Hashtbl.create 0)) in (let () = ignore ((List.iter (fun pair -> ignore ((sx_dict_set_b d (first (pair)) (nth (pair) ((Number 1.0)))))) (sx_to_list completed); Nil)) in (make_cek_value (d) (fenv) (rest_k)))) else (let next_entry = (first (remaining)) in (make_cek_state ((nth (next_entry) ((Number 1.0)))) (fenv) ((kont_push ((make_dict_frame ((rest (remaining))) ((prim_call "append" [completed; (List [(List [(first (next_entry))])])])) (fenv))) (rest_k)))))))) else (if sx_truthy ((prim_call "=" [_match_val; (String "ho-setup")])) then (let ho_type = (get (frame) ((String "ho-type"))) in let remaining = (get (frame) ((String "remaining"))) in let evaled = (prim_call "append" [(get (frame) ((String "evaled"))); (List [value])]) in let fenv = (get (frame) ((String "env"))) in (if sx_truthy ((empty_p (remaining))) then (ho_setup_dispatch (ho_type) (evaled) (fenv) (rest_k)) else (make_cek_state ((first (remaining))) (fenv) ((kont_push ((make_ho_setup_frame (ho_type) ((rest (remaining))) (evaled) (fenv))) (rest_k)))))) else (if sx_truthy ((prim_call "=" [_match_val; (String "reset")])) then (make_cek_value (value) (env) (rest_k)) else (if sx_truthy ((prim_call "=" [_match_val; (String "deref")])) then (let val' = value in let fenv = (get (frame) ((String "env"))) in (if sx_truthy ((Bool (not (sx_truthy ((is_signal (val'))))))) then (make_cek_value (val') (fenv) (rest_k)) else (if sx_truthy ((has_reactive_reset_frame_p (rest_k))) then (reactive_shift_deref (val') (fenv) (rest_k)) else (let () = ignore ((let ctx = (sx_context ((String "sx-reactive")) (Nil)) in (if sx_truthy (ctx) then (let dep_list = ref ((get (ctx) ((String "deps")))) in let notify_fn = (get (ctx) ((String "notify"))) in (if sx_truthy ((Bool (not (sx_truthy ((prim_call "contains?" [!dep_list; val'])))))) then (let () = ignore ((dep_list := sx_append_b !dep_list val'; Nil)) in (signal_add_sub_b (val') (notify_fn))) else Nil)) else Nil))) in (make_cek_value ((signal_value (val'))) (fenv) (rest_k)))))) else (if sx_truthy ((prim_call "=" [_match_val; (String "reactive-reset")])) then (let update_fn = (get (frame) ((String "update-fn"))) in let first_p = (get (frame) ((String "first-render"))) in (let () = ignore ((if sx_truthy ((let _and = update_fn in if not (sx_truthy _and) then _and else (Bool (not (sx_truthy (first_p)))))) then (cek_call (update_fn) ((List [value]))) else Nil)) in (make_cek_value (value) (env) (rest_k)))) else (if sx_truthy ((prim_call "=" [_match_val; (String "scope")])) then (let name = (get (frame) ((String "name"))) in let remaining = (get (frame) ((String "remaining"))) in let fenv = (get (frame) ((String "env"))) in (if sx_truthy ((empty_p (remaining))) then (let () = ignore ((scope_pop (name))) in (make_cek_value (value) (fenv) (rest_k))) else (make_cek_state ((first (remaining))) (fenv) ((kont_push ((make_scope_frame (name) ((rest (remaining))) (fenv))) (rest_k)))))) else (if sx_truthy ((prim_call "=" [_match_val; (String "provide")])) then (let remaining = (get (frame) ((String "remaining"))) in let fenv = (get (frame) ((String "env"))) in (if sx_truthy ((empty_p (remaining))) then (let () = ignore ((scope_pop ((get (frame) ((String "name")))))) in (make_cek_value (value) (fenv) (rest_k))) else (let new_frame = (make_provide_frame ((get (frame) ((String "name")))) ((get (frame) ((String "value")))) ((rest (remaining))) (fenv)) in (let () = ignore ((sx_dict_set_b new_frame (String "subscribers") (get (frame) ((String "subscribers"))))) in (make_cek_state ((first (remaining))) (fenv) ((kont_push (new_frame) (rest_k)))))))) else (if sx_truthy ((prim_call "=" [_match_val; (String "bind")])) then (let tracked = !_bind_tracking_ref in let body = (get (frame) ((String "body"))) in let fenv = (get (frame) ((String "env"))) in let prev = (get (frame) ((String "prev-tracking"))) in (let () = ignore ((_bind_tracking_ref := prev; Nil)) in (let () = ignore ((let subscriber = (NativeFn ("\206\187", fun _args -> match _args with [fire_kont] -> (fun fire_kont -> (let provide_kont = (kont_extract_provides (fire_kont)) in (cek_run ((make_cek_state (body) (fenv) (provide_kont)))))) fire_kont | _ -> Nil)) in (List.iter (fun pf -> ignore ((sx_dict_set_b pf (String "subscribers") (prim_call "append" [(get (pf) ((String "subscribers"))); (List [subscriber])])))) (sx_to_list tracked); Nil))) in (make_cek_value (value) (fenv) (rest_k))))) else (if sx_truthy ((prim_call "=" [_match_val; (String "provide-set")])) then (let name = (get (frame) ((String "name"))) in let fenv = (get (frame) ((String "env"))) in let target = (kont_find_provide (rest_k) (name)) in (if sx_truthy (target) then (let old_val = (get (target) ((String "value"))) in (let () = ignore ((sx_dict_set_b target (String "value") value)) in (let () = ignore ((scope_pop (name))) in (let () = ignore ((scope_push (name) (value))) in (let () = ignore ((if sx_truthy ((Bool (not (sx_truthy ((prim_call "=" [old_val; value])))))) then (fire_provide_subscribers (target) (rest_k)) else Nil)) in (make_cek_value (value) (fenv) (rest_k))))))) else (if sx_truthy ((env_has (fenv) ((String "provide-set!")))) then (let () = ignore ((sx_apply (env_get (fenv) ((String "provide-set!"))) (List [name; value]))) in (make_cek_value (value) (fenv) (rest_k))) else (make_cek_value (Nil) (fenv) (rest_k))))) else (if sx_truthy ((prim_call "=" [_match_val; (String "scope-acc")])) then (let remaining = (get (frame) ((String "remaining"))) in let fenv = (get (frame) ((String "env"))) in (if sx_truthy ((empty_p (remaining))) then (make_cek_value (value) (fenv) (rest_k)) else (make_cek_state ((first (remaining))) (fenv) ((kont_push ((let new_frame = (make_scope_acc_frame ((get (frame) ((String "name")))) ((get (frame) ((String "value")))) ((rest (remaining))) (fenv)) in (let () = ignore ((sx_dict_set_b new_frame (String "emitted") (get (frame) ((String "emitted"))))) in new_frame))) (rest_k)))))) else (if sx_truthy ((prim_call "=" [_match_val; (String "map")])) then (let f = (get (frame) ((String "f"))) in let remaining = (get (frame) ((String "remaining"))) in let results = (get (frame) ((String "results"))) in let indexed = (get (frame) ((String "indexed"))) in let fenv = (get (frame) ((String "env"))) in (let new_results = (prim_call "append" [results; (List [value])]) in (if sx_truthy ((empty_p (remaining))) then (make_cek_value (new_results) (fenv) (rest_k)) else (let call_args = (if sx_truthy (indexed) then (List [(len (new_results)); (first (remaining))]) else (List [(first (remaining))])) in let next_frame = (if sx_truthy (indexed) then (make_map_indexed_frame (f) ((rest (remaining))) (new_results) (fenv)) else (make_map_frame (f) ((rest (remaining))) (new_results) (fenv))) in (continue_with_call (f) (call_args) (fenv) ((List [])) ((kont_push (next_frame) (rest_k)))))))) else (if sx_truthy ((prim_call "=" [_match_val; (String "filter")])) then (let f = (get (frame) ((String "f"))) in let remaining = (get (frame) ((String "remaining"))) in let results = (get (frame) ((String "results"))) in let current_item = (get (frame) ((String "current-item"))) in let fenv = (get (frame) ((String "env"))) in (let new_results = (if sx_truthy (value) then (prim_call "append" [results; (List [current_item])]) else results) in (if sx_truthy ((empty_p (remaining))) then (make_cek_value (new_results) (fenv) (rest_k)) else (continue_with_call (f) ((List [(first (remaining))])) (fenv) ((List [])) ((kont_push ((make_filter_frame (f) ((rest (remaining))) (new_results) ((first (remaining))) (fenv))) (rest_k))))))) else (if sx_truthy ((prim_call "=" [_match_val; (String "reduce")])) then (let f = (get (frame) ((String "f"))) in let remaining = (get (frame) ((String "remaining"))) in let fenv = (get (frame) ((String "env"))) in (if sx_truthy ((empty_p (remaining))) then (make_cek_value (value) (fenv) (rest_k)) else (continue_with_call (f) ((List [value; (first (remaining))])) (fenv) ((List [])) ((kont_push ((make_reduce_frame (f) ((rest (remaining))) (fenv))) (rest_k)))))) else (if sx_truthy ((prim_call "=" [_match_val; (String "for-each")])) then (let f = (get (frame) ((String "f"))) in let remaining = (get (frame) ((String "remaining"))) in let fenv = (get (frame) ((String "env"))) in (if sx_truthy ((empty_p (remaining))) then (make_cek_value (Nil) (fenv) (rest_k)) else (continue_with_call (f) ((List [(first (remaining))])) (fenv) ((List [])) ((kont_push ((make_for_each_frame (f) ((rest (remaining))) (fenv))) (rest_k)))))) else (if sx_truthy ((prim_call "=" [_match_val; (String "some")])) then (let f = (get (frame) ((String "f"))) in let remaining = (get (frame) ((String "remaining"))) in let fenv = (get (frame) ((String "env"))) in (if sx_truthy (value) then (make_cek_value (value) (fenv) (rest_k)) else (if sx_truthy ((empty_p (remaining))) then (make_cek_value ((Bool false)) (fenv) (rest_k)) else (continue_with_call (f) ((List [(first (remaining))])) (fenv) ((List [])) ((kont_push ((make_some_frame (f) ((rest (remaining))) (fenv))) (rest_k))))))) else (if sx_truthy ((prim_call "=" [_match_val; (String "every")])) then (let f = (get (frame) ((String "f"))) in let remaining = (get (frame) ((String "remaining"))) in let fenv = (get (frame) ((String "env"))) in (if sx_truthy ((Bool (not (sx_truthy (value))))) then (make_cek_value ((Bool false)) (fenv) (rest_k)) else (if sx_truthy ((empty_p (remaining))) then (make_cek_value ((Bool true)) (fenv) (rest_k)) else (continue_with_call (f) ((List [(first (remaining))])) (fenv) ((List [])) ((kont_push ((make_every_frame (f) ((rest (remaining))) (fenv))) (rest_k))))))) else (if sx_truthy ((prim_call "=" [_match_val; (String "handler")])) then (let remaining = (get (frame) ((String "remaining"))) in let fenv = (get (frame) ((String "env"))) in (if sx_truthy ((empty_p (remaining))) then (make_cek_value (value) (fenv) (rest_k)) else (make_cek_state ((first (remaining))) (fenv) ((kont_push ((make_handler_frame ((get (frame) ((String "f")))) ((rest (remaining))) (fenv))) (rest_k)))))) else (if sx_truthy ((prim_call "=" [_match_val; (String "restart")])) then (make_cek_value (value) (env) (rest_k)) else (if sx_truthy ((prim_call "=" [_match_val; (String "signal-return")])) then (let saved_kont = (get (frame) ((String "saved-kont"))) in (make_cek_value (value) ((get (frame) ((String "env")))) (saved_kont))) else (if sx_truthy ((prim_call "=" [_match_val; (String "comp-trace")])) then (make_cek_value (value) (env) (rest_k)) else (if sx_truthy ((prim_call "=" [_match_val; (String "cond-arrow")])) then (let test_value = (get (frame) ((String "match-val"))) in let fenv = (get (frame) ((String "env"))) in (continue_with_call (value) ((List [test_value])) (fenv) ((List [test_value])) (rest_k))) else (if sx_truthy ((prim_call "=" [_match_val; (String "raise-eval")])) then (let condition = value in let fenv = (get (frame) ((String "env"))) in let continuable_p = (get (frame) ((String "scheme"))) in let handler_fn = (kont_find_handler (rest_k) (condition)) in (if sx_truthy ((is_nil (handler_fn))) then (let () = ignore ((_last_error_kont_ref := rest_k; Nil)) in (host_error ((String (sx_str [(String "Unhandled exception: "); (inspect (condition))]))))) else (continue_with_call (handler_fn) ((List [condition])) (fenv) ((List [condition])) ((if sx_truthy (continuable_p) then (kont_push ((make_signal_return_frame (fenv) (rest_k))) (rest_k)) else (kont_push ((make_raise_guard_frame (fenv) (rest_k))) (rest_k))))))) else (if sx_truthy ((prim_call "=" [_match_val; (String "raise-guard")])) then (let () = ignore ((_last_error_kont_ref := rest_k; Nil)) in (host_error ((String "exception handler returned from non-continuable raise")))) else (if sx_truthy ((prim_call "=" [_match_val; (String "multi-map")])) then (let f = (get (frame) ((String "f"))) in let remaining = (get (frame) ((String "remaining"))) in let new_results = (prim_call "append" [(get (frame) ((String "results"))); (List [value])]) in let fenv = (get (frame) ((String "env"))) in (if sx_truthy ((Bool (List.exists (fun c -> sx_truthy ((empty_p (c)))) (sx_to_list remaining)))) then (make_cek_value (new_results) (fenv) (rest_k)) else (let heads = (List (List.map (fun c -> (first (c))) (sx_to_list remaining))) in let tails = (List (List.map (fun c -> (rest (c))) (sx_to_list remaining))) in (continue_with_call (f) (heads) (fenv) ((List [])) ((kont_push ((make_multi_map_frame (f) (tails) (new_results) (fenv))) (rest_k))))))) else (if sx_truthy ((prim_call "=" [_match_val; (String "callcc")])) then (let k = (make_callcc_continuation (rest_k)) in (continue_with_call (value) ((List [k])) ((get (frame) ((String "env")))) ((List [k])) (rest_k))) else (if sx_truthy ((prim_call "=" [_match_val; (String "vm-resume")])) then (let resume_fn = (get (frame) ((String "f"))) in (let result' = (sx_apply resume_fn (List [value])) in (if sx_truthy ((let _and = (dict_p (result')) in if not (sx_truthy _and) then _and else (get (result') ((String "__vm_suspended"))))) then (make_cek_suspended ((get (result') ((String "request")))) ((get (frame) ((String "env")))) ((kont_push ((make_vm_resume_frame ((get (result') ((String "resume")))) ((get (frame) ((String "env")))))) (rest_k)))) else (make_cek_value (result') ((get (frame) ((String "env")))) (rest_k))))) else (if sx_truthy ((prim_call "=" [_match_val; (String "perform")])) then (make_cek_suspended (value) ((get (frame) ((String "env")))) (rest_k)) else (if sx_truthy ((prim_call "=" [_match_val; (String "import")])) then (let import_set = (get (frame) ((String "args"))) in let remaining_sets = (get (frame) ((String "remaining"))) in let fenv = (get (frame) ((String "env"))) in (let () = ignore ((bind_import_set (import_set) (fenv))) in (if sx_truthy ((empty_p (remaining_sets))) then (make_cek_value (Nil) (fenv) (rest_k)) else (step_sf_import (remaining_sets) (fenv) (rest_k))))) else (if sx_truthy ((prim_call "=" [_match_val; (String "parameterize")])) then (let remaining = (get (frame) ((String "remaining"))) in let current_param = (get (frame) ((String "f"))) in let results = (get (frame) ((String "results"))) in let body = (get (frame) ((String "body"))) in let fenv = (get (frame) ((String "env"))) in (if sx_truthy ((is_nil (current_param))) then (let param_obj = value in let val_expr = (nth ((first (remaining))) ((Number 1.0))) in (make_cek_state (val_expr) (fenv) ((kont_push ((make_parameterize_frame (remaining) (param_obj) (results) (body) (fenv))) (rest_k))))) else (let converted_val = value in let new_results = (prim_call "append" [results; (List [(List [(parameter_uid (current_param)); converted_val])])]) in let rest_bindings = (rest (remaining)) in (if sx_truthy ((empty_p (rest_bindings))) then (let body_expr = (if sx_truthy ((prim_call "=" [(len (body)); (Number 1.0)])) then (first (body)) else (cons ((Symbol "begin")) (body))) in let provide_kont = (kont_push_provides (new_results) (fenv) (rest_k)) in (make_cek_state (body_expr) (fenv) (provide_kont))) else (make_cek_state ((first ((first (rest_bindings))))) (fenv) ((kont_push ((make_parameterize_frame (rest_bindings) (Nil) (new_results) (body) (fenv))) (rest_k)))))))) else (let () = ignore ((_last_error_kont_ref := rest_k; Nil)) in (raise (Eval_error (value_to_str (String (sx_str [(String "Unknown frame type: "); ft])))))))))))))))))))))))))))))))))))))))))))))))))))
 
 (* continue-with-call *)
 and continue_with_call f args env raw_args kont =
@@ -833,9 +837,6 @@ let () = trampoline_fn := (fun v ->
 (* Wire up the primitives trampoline so call_any in HO forms resolves Thunks *)
 let () = Sx_primitives._sx_trampoline_fn := !trampoline_fn
 
-(* Wire up CEK call ref so primitives (e.g. with-capabilities) can invoke the evaluator *)
-let () = Sx_types._cek_call_ref := cek_call
-
 (* Override recursive cek_run with iterative loop.
    On error, capture the kont from the last state for comp-trace. *)
 let cek_run_iterative state =
@@ -846,25 +847,7 @@ let cek_run_iterative state =
       s := cek_step !s
     done;
     (match cek_suspended_p !s with
-     | Bool true ->
-       let request = cek_io_request !s in
-       let op = match request with Dict d -> (match Hashtbl.find_opt d "op" with Some (String s) -> s | _ -> "") | _ -> "" in
-       if op = "import" then begin
-         let lib_spec = match request with Dict d -> (match Hashtbl.find_opt d "library" with Some v -> v | _ -> Nil) | _ -> Nil in
-         let resolved = sx_truthy (library_loaded_p lib_spec) ||
-           (match !_import_hook with Some hook -> hook lib_spec | None -> false) in
-         if resolved then begin
-           s := cek_resume !s Nil;
-           (* Continue the step loop after resolving the import *)
-           while not (match cek_terminal_p !s with Bool true -> true | _ -> false)
-              && not (match cek_suspended_p !s with Bool true -> true | _ -> false) do
-             s := cek_step !s
-           done;
-           (match cek_suspended_p !s with
-            | Bool true -> raise (Eval_error "IO suspension in non-IO context")
-            | _ -> cek_value !s)
-         end else raise (Eval_error "IO suspension in non-IO context")
-       end else raise (Eval_error "IO suspension in non-IO context")
+     | Bool true -> raise (Eval_error "IO suspension in non-IO context")
      | _ -> cek_value !s)
   with Eval_error msg ->
     _last_error_kont_ref := cek_kont !s;
diff --git a/hosts/ocaml/lib/sx_runtime.ml b/hosts/ocaml/lib/sx_runtime.ml
index 7001b367..5c061a82 100644
--- a/hosts/ocaml/lib/sx_runtime.ml
+++ b/hosts/ocaml/lib/sx_runtime.ml
@@ -80,6 +80,15 @@ let sx_dict_set_b d k v =
   match d, k with
   | Dict tbl, String key -> Hashtbl.replace tbl key v; v
   | Dict tbl, Keyword key -> Hashtbl.replace tbl key v; v
+  | CekFrame f, String key ->
+    (match key with
+     | "value" | "extra" | "ho-type" | "scheme" | "indexed"
+     | "phase" | "has-effects" | "match-val" | "current-item"
+     | "update-fn" | "head-name" -> f.cf_extra <- v; v
+     | "remaining" -> f.cf_remaining <- v; v
+     | "subscribers" | "results" | "raw-args" -> f.cf_results <- v; v
+     | "emitted" | "effect-list" | "first-render" | "extra2" -> f.cf_extra2 <- v; v
+     | _ -> raise (Eval_error ("dict-set! cek-frame: unknown field " ^ key)))
   | VmFrame f, String key ->
     (match key with
      | "ip" -> f.vf_ip <- val_to_int v; v
@@ -116,6 +125,8 @@ let get_val container key =
      | "emitted" -> f.cf_extra2 | "effect-list" -> f.cf_extra2
      | "first-render" -> f.cf_extra2 | "file" -> f.cf_env
      | "extra" -> f.cf_extra | "extra2" -> f.cf_extra2
+     | "subscribers" -> f.cf_results
+     | "prev-tracking" -> f.cf_extra
      | _ -> Nil)
   | VmFrame f, String k ->
     (match k with
diff --git a/hosts/ocaml/lib/sx_types.ml b/hosts/ocaml/lib/sx_types.ml
index 10201777..4196f50f 100644
--- a/hosts/ocaml/lib/sx_types.ml
+++ b/hosts/ocaml/lib/sx_types.ml
@@ -91,12 +91,12 @@ and cek_frame = {
   cf_env       : value;         (* environment — every frame has this *)
   cf_name      : value;         (* let/define/set/scope: binding name *)
   cf_body      : value;         (* when/let: body expr *)
-  cf_remaining : value;         (* begin/cond/map/etc: remaining exprs *)
+  mutable cf_remaining : value;  (* begin/cond/map/etc: remaining exprs *)
   cf_f         : value;         (* call/map/filter/etc: function *)
   cf_args      : value;         (* call: raw args; arg: evaled args *)
-  cf_results   : value;         (* map/filter/dict: accumulated results *)
+  mutable cf_results   : value; (* map/filter/dict: accumulated results; provide: subscribers *)
   mutable cf_extra : value;     (* extra field: scheme, indexed, value, phase, etc. *)
-  cf_extra2    : value;         (* second extra: emitted, etc. *)
+  mutable cf_extra2    : value; (* second extra: emitted, etc. *)
 }
 
 (** Mutable string-keyed table (SX dicts support [dict-set!]). *)
diff --git a/hosts/ocaml/transpiler.sx b/hosts/ocaml/transpiler.sx
index f8b083c2..be4934e9 100644
--- a/hosts/ocaml/transpiler.sx
+++ b/hosts/ocaml/transpiler.sx
@@ -285,7 +285,7 @@
 
 (define
   ml-mutable-globals
-  (list "*strict*" "*prim-param-types*" "*last-error-kont*"))
+  (list "*strict*" "*prim-param-types*" "*last-error-kont*" "*bind-tracking*"))
 
 (define
   ml-is-mutable-global?
@@ -539,6 +539,8 @@
                 (ef "results")
                 (some (fn (k) (= k "raw-args")) items)
                 (ef "raw-args")
+                (some (fn (k) (= k "subscribers")) items)
+                (ef "subscribers")
                 :else "Nil")
               "; cf_extra = "
               (cond
@@ -562,6 +564,8 @@
                 (ef "update-fn")
                 (some (fn (k) (= k "head-name")) items)
                 (ef "head-name")
+                (some (fn (k) (= k "prev-tracking")) items)
+                (ef "prev-tracking")
                 (some (fn (k) (= k "extra")) items)
                 (ef "extra")
                 :else "Nil")
diff --git a/spec/evaluator.sx b/spec/evaluator.sx
index c6f9b32b..9611ead8 100644
--- a/spec/evaluator.sx
+++ b/spec/evaluator.sx
@@ -108,43 +108,53 @@
 
 (define make-scope-frame (fn (name remaining env) {:env env :type "scope" :remaining remaining :name name}))
 
-(define make-provide-frame (fn (name value remaining env) {:env env :value value :type "provide" :remaining remaining :name name}))
+(define make-provide-frame (fn (name value remaining env) {:subscribers (list) :env env :value value :type "provide" :remaining remaining :name name}))
+
+(define make-bind-frame (fn (body env prev-tracking) {:body body :env env :type "bind" :prev-tracking prev-tracking}))
+
+;; Dynamic wind + reactive signals
+(define make-provide-set-frame (fn (name env) {:env env :type "provide-set" :name name}))
 
 (define make-scope-acc-frame (fn (name value remaining env) {:env env :value (or value nil) :type "scope-acc" :remaining remaining :emitted (list) :name name}))
 
-;; Dynamic wind + reactive signals
+;; Undelimited continuations (call/cc)
 (define make-reset-frame (fn (env) {:env env :type "reset"}))
 
 (define make-dict-frame (fn (remaining results env) {:env env :results results :type "dict" :remaining remaining}))
 
-;; Undelimited continuations (call/cc)
+;; HO setup: staged argument evaluation for map/filter/etc.
+;; Evaluates args one at a time, then dispatches to the correct
+;; HO frame (map, filter, reduce) once all args are ready.
 (define make-and-frame (fn (remaining env) {:env env :type "and" :remaining remaining}))
 
 (define make-or-frame (fn (remaining env) {:env env :type "or" :remaining remaining}))
 
-;; HO setup: staged argument evaluation for map/filter/etc.
-;; Evaluates args one at a time, then dispatches to the correct
-;; HO frame (map, filter, reduce) once all args are ready.
 (define
   make-dynamic-wind-frame
   (fn (phase body-thunk after-thunk env) {:env env :phase phase :after-thunk after-thunk :type "dynamic-wind" :body-thunk body-thunk}))
 
+;; Condition system frames (handler-bind, restart-case, signal)
 (define
   make-reactive-reset-frame
   (fn (env update-fn first-render?) {:first-render first-render? :update-fn update-fn :env env :type "reactive-reset"}))
 
 (define make-callcc-frame (fn (env) {:env env :type "callcc"}))
 
-;; Condition system frames (handler-bind, restart-case, signal)
 (define make-deref-frame (fn (env) {:env env :type "deref"}))
 
+;; R7RS exception frames (raise, guard)
 (define
   make-ho-setup-frame
   (fn (ho-type remaining-args evaled-args env) {:ho-type ho-type :env env :evaled evaled-args :type "ho-setup" :remaining remaining-args}))
 
 (define make-comp-trace-frame (fn (name file) {:env file :type "comp-trace" :name name}))
 
-;; R7RS exception frames (raise, guard)
+;; ═══════════════════════════════════════════════════════════════
+;; Part 3: Continuation Stack Operations
+;;
+;; Searching and manipulating the kont list — finding handlers,
+;; restarts, scope accumulators, and capturing delimited slices.
+;; ═══════════════════════════════════════════════════════════════
 (define
   kont-collect-comp-trace
   (fn
@@ -161,27 +171,22 @@
 
 (define make-handler-frame (fn (handlers remaining env) {:env env :type "handler" :f handlers :remaining remaining}))
 
-;; ═══════════════════════════════════════════════════════════════
-;; Part 3: Continuation Stack Operations
-;;
-;; Searching and manipulating the kont list — finding handlers,
-;; restarts, scope accumulators, and capturing delimited slices.
-;; ═══════════════════════════════════════════════════════════════
 (define make-restart-frame (fn (restarts remaining env) {:env env :type "restart" :f restarts :remaining remaining}))
 
 (define make-signal-return-frame (fn (env saved-kont) {:env env :type "signal-return" :f saved-kont}))
 
+;; Basic kont operations
 (define make-raise-eval-frame (fn (env continuable?) {:scheme continuable? :env env :type "raise-eval"}))
 
 (define make-raise-guard-frame (fn (env saved-kont) {:env env :type "raise-guard" :remaining saved-kont}))
 
-;; Basic kont operations
 (define make-perform-frame (fn (env) {:env env :type "perform"}))
 
 (define make-vm-resume-frame (fn (resume-fn env) {:env env :type "vm-resume" :f resume-fn}))
 
 (define make-import-frame (fn (import-set remaining-sets env) {:args import-set :env env :type "import" :remaining remaining-sets}))
 
+;; Capture frames up to a reset boundary — used by shift
 (define
   make-parameterize-frame
   (fn (remaining current-param results body env) {:env env :body body :results results :type "parameterize" :f current-param :remaining remaining}))
@@ -202,7 +207,6 @@
             handler-fn
             (find-matching-handler (rest handlers) condition)))))))
 
-;; Capture frames up to a reset boundary — used by shift
 (define
   kont-find-handler
   (fn
@@ -255,16 +259,16 @@
               (list match frame (rest kont))))
           (kont-find-restart (rest kont) name))))))
 
-(define frame-type (fn (f) (get f "type")))
-
-(define kont-push (fn (frame kont) (cons frame kont)))
-
 ;; ═══════════════════════════════════════════════════════════════
 ;; Part 4: Extension Points & Mutable State
 ;;
 ;; Custom special forms registry, render hooks, strict mode.
 ;; Mutable globals use set! — the transpiler emits OCaml refs.
 ;; ═══════════════════════════════════════════════════════════════
+(define frame-type (fn (f) (get f "type")))
+
+(define kont-push (fn (frame kont) (cons frame kont)))
+
 (define kont-top (fn (kont) (first kont)))
 
 (define kont-pop (fn (kont) (rest kont)))
@@ -371,14 +375,6 @@
               (scan (rest k) (append captured (list frame))))))))
     (scan kont (list))))
 
-(define *custom-special-forms* (dict))
-
-(define
-  register-special-form!
-  (fn
-    ((name :as string) handler)
-    (dict-set! *custom-special-forms* name handler)))
-
 ;; ═══════════════════════════════════════════════════════════════
 ;; Part 5: Evaluation Utilities
 ;;
@@ -387,15 +383,26 @@
 ;; defmacro, quasiquote), and macro expansion.
 ;; ═══════════════════════════════════════════════════════════════
 ;; Forward declaration — redefined at end of file as CEK entry point
-(define *render-check* nil)
+(define *custom-special-forms* (dict))
 
 ;; Shared param binding for lambda/component calls.
 ;; Handles &rest collection — used by both call-lambda and continue-with-call.
-(define *render-fn* nil)
+(define
+  register-special-form!
+  (fn
+    ((name :as string) handler)
+    (dict-set! *custom-special-forms* name handler)))
 
-(define *library-registry* (dict))
+(define *render-check* nil)
 
 ;; Component calls: parse keyword args, bind params, TCO thunk
+(define *render-fn* nil)
+
+(define *bind-tracking* nil)
+
+;; Cond/case helpers
+(define *library-registry* (dict))
+
 (define
   library-name-key
   (fn
@@ -404,11 +411,11 @@
       "."
       (map (fn (s) (if (symbol? s) (symbol-name s) (str s))) spec))))
 
+;; Special form constructors — build state for CEK evaluation
 (define
   library-loaded?
   (fn (spec) (has-key? *library-registry* (library-name-key spec))))
 
-;; Cond/case helpers
 (define
   library-exports
   (fn
@@ -421,7 +428,6 @@
     (spec exports)
     (dict-set! *library-registry* (library-name-key spec) {:exports exports})))
 
-;; Special form constructors — build state for CEK evaluation
 (define *io-registry* (dict))
 
 (define io-register! (fn (name spec) (dict-set! *io-registry* name spec)))
@@ -432,6 +438,7 @@
 
 (define io-names (fn () (keys *io-registry*)))
 
+;; Quasiquote expansion
 (define
   step-sf-io
   (fn
@@ -458,13 +465,13 @@
 
 (define *strict* false)
 
-;; Quasiquote expansion
 (define set-strict! (fn (val) (set! *strict* val)))
 
 (define *prim-param-types* nil)
 
 (define set-prim-param-types! (fn (types) (set! *prim-param-types* types)))
 
+;; Macro expansion — expand then re-evaluate the result
 (define
   value-matches-type?
   (fn
@@ -491,6 +498,14 @@
               (slice expected-type 0 (- (string-length expected-type) 1))))
           true)))))
 
+;; ═══════════════════════════════════════════════════════════════
+;; Part 6: CEK Machine Core
+;;
+;; cek-run: trampoline loop — steps until terminal.
+;; cek-step: single step — dispatches on phase (eval vs continue).
+;; step-eval: evaluates control expression, pushes frames.
+;; step-continue: pops a frame, processes result.
+;; ═══════════════════════════════════════════════════════════════
 (define
   strict-check-args
   (fn
@@ -562,7 +577,6 @@
 
 (define eval-expr (fn (expr (env :as dict)) nil))
 
-;; Macro expansion — expand then re-evaluate the result
 (define
   bind-lambda-params
   (fn
@@ -588,12 +602,10 @@
         false))))
 
 ;; ═══════════════════════════════════════════════════════════════
-;; Part 6: CEK Machine Core
+;; Part 7: Special Form Step Functions
 ;;
-;; cek-run: trampoline loop — steps until terminal.
-;; cek-step: single step — dispatches on phase (eval vs continue).
-;; step-eval: evaluates control expression, pushes frames.
-;; step-continue: pops a frame, processes result.
+;; Each step-sf-* handles one special form in the eval phase.
+;; They push frames and return new CEK states — never recurse.
 ;; ═══════════════════════════════════════════════════════════════
 (define
   call-lambda
@@ -621,6 +633,7 @@
           (slice params (len args))))
       (make-thunk (lambda-body f) local))))
 
+;; R7RS guard: desugars to call/cc + handler-bind with sentinel re-raise
 (define
   call-component
   (fn
@@ -638,6 +651,9 @@
         (env-bind! local "children" children))
       (make-thunk (component-body comp) local))))
 
+;; List evaluation — dispatches on head: special forms, macros,
+;; higher-order forms, or function calls. This is the main
+;; expression dispatcher for the CEK machine.
 (define
   parse-keyword-args
   (fn
@@ -669,12 +685,7 @@
         raw-args)
       (list kwargs children))))
 
-;; ═══════════════════════════════════════════════════════════════
-;; Part 7: Special Form Step Functions
-;;
-;; Each step-sf-* handles one special form in the eval phase.
-;; They push frames and return new CEK states — never recurse.
-;; ═══════════════════════════════════════════════════════════════
+;; call/cc: capture entire kont as undelimited escape continuation
 (define
   cond-scheme?
   (fn
@@ -692,7 +703,6 @@
               (= (symbol-name (nth c 1)) "=>")))))
       clauses)))
 
-;; R7RS guard: desugars to call/cc + handler-bind with sentinel re-raise
 (define
   is-else-clause?
   (fn
@@ -703,9 +713,6 @@
         (= (type-of test) "symbol")
         (or (= (symbol-name test) "else") (= (symbol-name test) ":else"))))))
 
-;; List evaluation — dispatches on head: special forms, macros,
-;; higher-order forms, or function calls. This is the main
-;; expression dispatcher for the CEK machine.
 (define
   sf-named-let
   (fn
@@ -753,7 +760,7 @@
           ((init-vals (map (fn (e) (trampoline (eval-expr e env))) inits)))
           (cek-call loop-fn init-vals))))))
 
-;; call/cc: capture entire kont as undelimited escape continuation
+;; Pattern matching (match form)
 (define
   sf-lambda
   (fn
@@ -783,6 +790,7 @@
             params-expr)))
       (make-lambda param-names body env))))
 
+;; Condition system special forms
 (define
   sf-defcomp
   (fn
@@ -842,7 +850,6 @@
         (range 2 end 1))
       result)))
 
-;; Pattern matching (match form)
 (define
   parse-comp-params
   (fn
@@ -889,7 +896,6 @@
         params-expr)
       (list params has-children param-types))))
 
-;; Condition system special forms
 (define
   sf-defisland
   (fn
@@ -1181,6 +1187,7 @@
       state
       (cek-step-loop (cek-step state)))))
 
+;; Scope/provide/context — structured downward data passing
 (define
   cek-run
   (fn
@@ -1211,7 +1218,6 @@
       (step-eval state)
       (step-continue state))))
 
-;; Scope/provide/context — structured downward data passing
 (define
   step-eval
   (fn
@@ -1268,6 +1274,18 @@
           (step-eval-list expr env kont))
         :else (make-cek-value expr env kont)))))
 
+;; ═══════════════════════════════════════════════════════════════
+;; R7RS syntax-rules / define-syntax
+;;
+;; syntax-rules creates a macro transformer via pattern matching.
+;; define-syntax binds the transformer as a macro (reuses define).
+;; Pattern language: _ (wildcard), literals (exact match),
+;; pattern variables (bind), ... (ellipsis/repetition).
+;; ═══════════════════════════════════════════════════════════════
+
+;; Match a syntax-rules pattern against a form.
+;; Returns a dict of bindings on success, nil on failure.
+;; literals is a list of symbol name strings that must match exactly.
 (define
   step-sf-raise
   (fn
@@ -1277,6 +1295,8 @@
       env
       (kont-push (make-raise-eval-frame env false) kont))))
 
+;; Match a list pattern against a form list, handling ellipsis at any position.
+;; pi = pattern index, fi = form index.
 (define
   step-sf-guard
   (fn
@@ -1350,6 +1370,8 @@
         env
         kont))))
 
+;; Find which pattern variable in a template drives an ellipsis.
+;; Returns the variable name (string) whose binding is a list, or nil.
 (define
   step-sf-callcc
   (fn
@@ -1359,18 +1381,8 @@
       env
       (kont-push (make-callcc-frame env) kont))))
 
-;; ═══════════════════════════════════════════════════════════════
-;; R7RS syntax-rules / define-syntax
-;;
-;; syntax-rules creates a macro transformer via pattern matching.
-;; define-syntax binds the transformer as a macro (reuses define).
-;; Pattern language: _ (wildcard), literals (exact match),
-;; pattern variables (bind), ... (ellipsis/repetition).
-;; ═══════════════════════════════════════════════════════════════
-
-;; Match a syntax-rules pattern against a form.
-;; Returns a dict of bindings on success, nil on failure.
-;; literals is a list of symbol name strings that must match exactly.
+;; Find ALL ellipsis-bound pattern variables in a template.
+;; Returns a list of variable name strings.
 (define
   step-sf-case
   (fn
@@ -1380,8 +1392,8 @@
       env
       (kont-push (make-case-frame nil (rest args) env) kont))))
 
-;; Match a list pattern against a form list, handling ellipsis at any position.
-;; pi = pattern index, fi = form index.
+;; Instantiate a template with pattern variable bindings.
+;; Handles ellipsis repetition and recursive substitution.
 (define
   step-sf-let-match
   (fn
@@ -1395,8 +1407,9 @@
         env
         kont))))
 
-;; Find which pattern variable in a template drives an ellipsis.
-;; Returns the variable name (string) whose binding is a list, or nil.
+;; Walk a template list, handling ellipsis at any position.
+;; When element at i is followed by ... at i+1, expand the element
+;; for each value of its ellipsis variables (all cycled in parallel).
 (define
   step-eval-list
   (fn
@@ -1509,6 +1522,7 @@
               ("peek" (step-sf-peek args env kont))
               ("provide!" (step-sf-provide! args env kont))
               ("context" (step-sf-context args env kont))
+              ("bind" (step-sf-bind args env kont))
               ("emit!" (step-sf-emit args env kont))
               ("emitted" (step-sf-emitted args env kont))
               ("handler-bind" (step-sf-handler-bind args env kont))
@@ -1563,8 +1577,51 @@
                   :else (step-eval-call head args env kont)))))
           (step-eval-call head args env kont))))))
 
-;; Find ALL ellipsis-bound pattern variables in a template.
-;; Returns a list of variable name strings.
+;; Try each syntax-rules clause against a form.
+;; Returns the instantiated template for the first matching rule, or errors.
+;; form is the raw args (without macro name). We prepend a dummy _ symbol
+;; because syntax-rules patterns include the keyword as the first element.
+(define
+  kont-extract-provides
+  (fn
+    (kont)
+    (if
+      (empty? kont)
+      (list)
+      (let
+        ((frame (first kont))
+          (rest-frames (kont-extract-provides (rest kont))))
+        (if
+          (= (frame-type frame) "provide")
+          (cons {:subscribers (list) :env (get frame "env") :value (get frame "value") :type "provide" :remaining (list) :name (get frame "name")} rest-frames)
+          rest-frames)))))
+
+(define
+  fire-provide-subscribers
+  (fn
+    (frame kont)
+    (let
+      ((subs (get frame "subscribers")))
+      (when
+        (not (empty? subs))
+        (for-each (fn (sub) (cek-call sub (list kont))) subs)))))
+
+;; Special form: (syntax-rules (literal ...) (pattern template) ...)
+;; Creates a Macro with rules/literals stored in closure env.
+;; Body is a marker symbol; expand-macro detects it and calls
+;; the pattern matcher directly.
+(define
+  step-sf-bind
+  (fn
+    (args env kont)
+    (let
+      ((body (first args)) (prev *bind-tracking*))
+      (set! *bind-tracking* (list))
+      (make-cek-state
+        body
+        env
+        (kont-push (make-bind-frame body env prev) kont)))))
+
 (define
   step-sf-parameterize
   (fn
@@ -1583,8 +1640,17 @@
               (make-parameterize-frame bindings nil (list) body env)
               kont)))))))
 
-;; Instantiate a template with pattern variable bindings.
-;; Handles ellipsis repetition and recursive substitution.
+;; R7RS records (SRFI-9)
+;;
+;; (define-record-type <point>
+;;   (make-point x y)
+;;   point?
+;;   (x point-x)
+;;   (y point-y set-point-y!))
+;;
+;; Creates: constructor, predicate, accessors, optional mutators.
+;; Opaque — only accessible through generated functions.
+;; Generative — each call creates a unique type.
 (define
   syntax-rules-match
   (fn
@@ -1605,9 +1671,7 @@
       (syntax-rules-match-list pattern 0 form 0 literals)
       :else (if (= pattern form) (dict) nil))))
 
-;; Walk a template list, handling ellipsis at any position.
-;; When element at i is followed by ... at i+1, expand the element
-;; for each value of its ellipsis variables (all cycled in parallel).
+;; Delimited continuations
 (define
   syntax-rules-match-list
   (fn
@@ -1690,10 +1754,6 @@
                     (keys sub-result))
                   rest-result)))))))))
 
-;; Try each syntax-rules clause against a form.
-;; Returns the instantiated template for the first matching rule, or errors.
-;; form is the raw args (without macro name). We prepend a dummy _ symbol
-;; because syntax-rules patterns include the keyword as the first element.
 (define
   syntax-rules-find-var
   (fn
@@ -1713,6 +1773,7 @@
         template)
       :else nil)))
 
+;; Signal dereferencing with reactive dependency tracking
 (define
   syntax-rules-find-all-vars
   (fn
@@ -1730,10 +1791,13 @@
         template)
       :else (list))))
 
-;; Special form: (syntax-rules (literal ...) (pattern template) ...)
-;; Creates a Macro with rules/literals stored in closure env.
-;; Body is a marker symbol; expand-macro detects it and calls
-;; the pattern matcher directly.
+;; ═══════════════════════════════════════════════════════════════
+;; Part 8: Call Dispatch
+;;
+;; cek-call: invoke a function from native code (runs a nested
+;; trampoline). step-eval-call: CEK-native call dispatch for
+;; lambda, component, native fn, and continuations.
+;; ═══════════════════════════════════════════════════════════════
 (define
   syntax-rules-instantiate
   (fn
@@ -1747,6 +1811,7 @@
       template
       :else (syntax-rules-instantiate-list template 0 bindings))))
 
+;; Reactive signal tracking — captures dependency continuation for re-render
 (define
   syntax-rules-instantiate-list
   (fn
@@ -1796,17 +1861,6 @@
             (syntax-rules-instantiate elem bindings)
             (syntax-rules-instantiate-list template (+ i 1) bindings)))))))
 
-;; R7RS records (SRFI-9)
-;;
-;; (define-record-type <point>
-;;   (make-point x y)
-;;   point?
-;;   (x point-x)
-;;   (y point-y set-point-y!))
-;;
-;; Creates: constructor, predicate, accessors, optional mutators.
-;; Opaque — only accessible through generated functions.
-;; Generative — each call creates a unique type.
 (define
   syntax-rules-expand
   (fn
@@ -1815,7 +1869,13 @@
       ((full-form (cons (make-symbol "_") form)))
       (syntax-rules-try-rules literals rules full-form))))
 
-;; Delimited continuations
+;; ═══════════════════════════════════════════════════════════════
+;; Part 9: Higher-Order Form Machinery
+;;
+;; Data-first HO forms: (map coll fn) and (map fn coll) both work.
+;; ho-swap-args auto-detects argument order. HoSetupFrame stages
+;; argument evaluation, then dispatches to the appropriate step-ho-*.
+;; ═══════════════════════════════════════════════════════════════
 (define
   syntax-rules-try-rules
   (fn
@@ -1853,7 +1913,6 @@
           closure
           "syntax-rules")))))
 
-;; Signal dereferencing with reactive dependency tracking
 (define
   step-sf-define-library
   (fn
@@ -1898,13 +1957,6 @@
           (register-library lib-spec export-dict)
           (make-cek-value nil env kont))))))
 
-;; ═══════════════════════════════════════════════════════════════
-;; Part 8: Call Dispatch
-;;
-;; cek-call: invoke a function from native code (runs a nested
-;; trampoline). step-eval-call: CEK-native call dispatch for
-;; lambda, component, native fn, and continuations.
-;; ═══════════════════════════════════════════════════════════════
 (define
   bind-import-set
   (fn
@@ -1936,7 +1988,6 @@
               (fn (key) (env-bind! env key (get exports key)))
               (keys exports))))))))
 
-;; Reactive signal tracking — captures dependency continuation for re-render
 (define
   step-sf-import
   (fn
@@ -1973,13 +2024,6 @@
         env
         (kont-push (make-perform-frame env) kont)))))
 
-;; ═══════════════════════════════════════════════════════════════
-;; Part 9: Higher-Order Form Machinery
-;;
-;; Data-first HO forms: (map coll fn) and (map fn coll) both work.
-;; ho-swap-args auto-detects argument order. HoSetupFrame stages
-;; argument evaluation, then dispatches to the appropriate step-ho-*.
-;; ═══════════════════════════════════════════════════════════════
 (define *protocol-registry* (dict))
 
 (define
@@ -2181,6 +2225,14 @@
             (dict-set! impls type-name type-impls)
             nil))))))
 
+;; ═══════════════════════════════════════════════════════════════
+;; Part 10: Continue Phase — Frame Dispatch
+;;
+;; When phase="continue", pop the top frame and process the value.
+;; Each frame type has its own handling: if frames check truthiness,
+;; let frames bind the value, arg frames accumulate it, etc.
+;; continue-with-call handles the final function/component dispatch.
+;; ═══════════════════════════════════════════════════════════════
 (define
   satisfies?
   (fn
@@ -2195,6 +2247,9 @@
           false
           (not (nil? (get (get proto "impls") (type-of value)))))))))
 
+;; Final call dispatch from arg frame — all args evaluated, invoke function.
+;; Handles: lambda (bind params + TCO), component (keyword args + TCO),
+;; native fn (direct call), continuation (resume), callcc continuation (escape).
 (define
   check-match-exhaustiveness
   (fn
@@ -2252,6 +2307,13 @@
           (list local body)
           (match-find-clause val (rest clauses) env))))))
 
+;; ═══════════════════════════════════════════════════════════════
+;; Part 11: Entry Points
+;;
+;; eval-expr-cek / trampoline-cek: CEK evaluation entry points.
+;; eval-expr / trampoline: top-level bindings that override the
+;; forward declarations from Part 5.
+;; ═══════════════════════════════════════════════════════════════
 (define
   match-pattern
   (fn
@@ -2337,14 +2399,6 @@
           env
           (kont-push (make-handler-frame handlers (rest body) env) kont))))))
 
-;; ═══════════════════════════════════════════════════════════════
-;; Part 10: Continue Phase — Frame Dispatch
-;;
-;; When phase="continue", pop the top frame and process the value.
-;; Each frame type has its own handling: if frames check truthiness,
-;; let frames bind the value, arg frames accumulate it, etc.
-;; continue-with-call handles the final function/component dispatch.
-;; ═══════════════════════════════════════════════════════════════
 (define
   step-sf-restart-case
   (fn
@@ -2369,9 +2423,6 @@
         env
         (kont-push (make-restart-frame restarts (list) env) kont)))))
 
-;; Final call dispatch from arg frame — all args evaluated, invoke function.
-;; Handles: lambda (bind params + TCO), component (keyword args + TCO),
-;; native fn (direct call), continuation (resume), callcc continuation (escape).
 (define
   step-sf-signal
   (fn
@@ -2417,13 +2468,6 @@
               (env-bind! restart-env (first params) restart-arg))
             (make-cek-state body restart-env rest-kont)))))))
 
-;; ═══════════════════════════════════════════════════════════════
-;; Part 11: Entry Points
-;;
-;; eval-expr-cek / trampoline-cek: CEK evaluation entry points.
-;; eval-expr / trampoline: top-level bindings that override the
-;; forward declarations from Part 5.
-;; ═══════════════════════════════════════════════════════════════
 (define
   step-sf-if
   (fn
@@ -2679,9 +2723,10 @@
       ((name (trampoline (eval-expr (first args) env)))
         (val (trampoline (eval-expr (nth args 1) env)))
         (body (slice args 2)))
+      (scope-push! name val)
       (if
         (empty? body)
-        (make-cek-value nil env kont)
+        (do (scope-pop! name) (make-cek-value nil env kont))
         (make-cek-state
           (first body)
           env
@@ -2699,14 +2744,16 @@
             (trampoline (eval-expr (nth args 1) env))
             nil))
         (frame (kont-find-provide kont name)))
+      (when
+        (and frame *bind-tracking*)
+        (when
+          (not (contains? *bind-tracking* frame))
+          (append! *bind-tracking* frame)))
       (make-cek-value
         (if
           frame
           (get frame "value")
-          (if
-            (env-has? env "context")
-            (apply (env-get env "context") (list name default-val))
-            default-val))
+          (let ((sv (scope-peek name))) (if (nil? sv) default-val sv)))
         env
         kont))))
 
@@ -2738,20 +2785,11 @@
   (fn
     (args env kont)
     (let
-      ((name (trampoline (eval-expr (first args) env)))
-        (new-val (trampoline (eval-expr (nth args 1) env)))
-        (frame (kont-find-provide kont name)))
-      (if
-        frame
-        (do
-          (dict-set! frame "value" new-val)
-          (make-cek-value new-val env kont))
-        (if
-          (env-has? env "provide-set!")
-          (do
-            (apply (env-get env "provide-set!") (list name new-val))
-            (make-cek-value new-val env kont))
-          (make-cek-value nil env kont))))))
+      ((name (trampoline (eval-expr (first args) env))))
+      (make-cek-state
+        (nth args 1)
+        env
+        (kont-push (make-provide-set-frame name env) kont)))))
 
 (define
   step-sf-emit
@@ -3538,17 +3576,59 @@
                   (fenv (get frame "env")))
                 (if
                   (empty? remaining)
-                  (make-cek-value value fenv rest-k)
-                  (make-cek-state
-                    (first remaining)
-                    fenv
-                    (kont-push
-                      (make-provide-frame
-                        (get frame "name")
-                        (get frame "value")
-                        (rest remaining)
-                        fenv)
-                      rest-k)))))
+                  (do
+                    (scope-pop! (get frame "name"))
+                    (make-cek-value value fenv rest-k))
+                  (let
+                    ((new-frame (make-provide-frame (get frame "name") (get frame "value") (rest remaining) fenv)))
+                    (dict-set!
+                      new-frame
+                      "subscribers"
+                      (get frame "subscribers"))
+                    (make-cek-state
+                      (first remaining)
+                      fenv
+                      (kont-push new-frame rest-k))))))
+            ("bind"
+              (let
+                ((tracked *bind-tracking*)
+                  (body (get frame "body"))
+                  (fenv (get frame "env"))
+                  (prev (get frame "prev-tracking")))
+                (set! *bind-tracking* prev)
+                (let
+                  ((subscriber (fn (fire-kont) (let ((provide-kont (kont-extract-provides fire-kont))) (cek-run (make-cek-state body fenv provide-kont))))))
+                  (for-each
+                    (fn
+                      (pf)
+                      (dict-set!
+                        pf
+                        "subscribers"
+                        (append (get pf "subscribers") (list subscriber))))
+                    tracked))
+                (make-cek-value value fenv rest-k)))
+            ("provide-set"
+              (let
+                ((name (get frame "name"))
+                  (fenv (get frame "env"))
+                  (target (kont-find-provide rest-k name)))
+                (if
+                  target
+                  (let
+                    ((old-val (get target "value")))
+                    (dict-set! target "value" value)
+                    (scope-pop! name)
+                    (scope-push! name value)
+                    (when
+                      (not (= old-val value))
+                      (fire-provide-subscribers target rest-k))
+                    (make-cek-value value fenv rest-k))
+                  (if
+                    (env-has? fenv "provide-set!")
+                    (do
+                      (apply (env-get fenv "provide-set!") (list name value))
+                      (make-cek-value value fenv rest-k))
+                    (make-cek-value nil fenv rest-k)))))
             ("scope-acc"
               (let
                 ((remaining (get frame "remaining"))
diff --git a/spec/tests/test-unified-reactive.sx b/spec/tests/test-unified-reactive.sx
index e3619a79..3b361c82 100644
--- a/spec/tests/test-unified-reactive.sx
+++ b/spec/tests/test-unified-reactive.sx
@@ -106,7 +106,7 @@
       :prefix "item-"
       (assert-equal
         (list "item-a" "item-b")
-        (map (fn (x) (string-append (context :prefix) x)) (list "a" "b")))))
+        (map (fn (x) (str (context :prefix) x)) (list "a" "b")))))
   (deftest
     "context with keyword name"
     (provide :my-key 99 (assert-equal 99 (context :my-key)))))
@@ -260,10 +260,7 @@
       :x 5
       (assert-equal
         "value: 5"
-        (bind
-          (let
-            ((v (context :x)))
-            (string-append "value: " (number->string v)))))))
+        (bind (let ((v (context :x))) (str "value: " v))))))
   (deftest
     "bind no deps is static"
     (let
@@ -532,7 +529,7 @@
     "guard inside bind"
     (provide
       :x 1
-      (assert-equal 1 (bind (guard (exn (#t -1)) (context :x))))))
+      (assert-equal 1 (bind (guard (exn (true -1)) (context :x))))))
   (deftest
     "bind with string-append"
     (provide
@@ -541,4 +538,4 @@
         :second "world"
         (assert-equal
           "hello world"
-          (bind (string-append (context :first) " " (context :second))))))))
+          (bind (str (context :first) " " (context :second))))))))