Lambda→CEK dispatch: enable IO suspension through sx_call

Lambda calls in sx_call now go through the CEK machine instead of
returning a Thunk for the tree-walker trampoline. This lets perform/
IO suspension work everywhere — including hyperscript wait/bounce.

Key changes:
- sx_runtime: Lambda case calls _cek_eval_lambda_ref (forward ref)
- sx_vm: initializes ref with cek_step_loop + stub VM for suspension
- sx_apply_cek: VmSuspended → __vm_suspended marker dict (not exception)
- continue_with_call callable path: handles __vm_suspended with
  vm-resume-frame, matching the existing JIT Lambda pattern
- sx_render: let VmSuspended propagate through try_catch
- Remove invalid io-contract test (perform now suspends, not errors)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

hosts/ocaml/lib/sx_ref.ml

@@ -572,9 +572,16 @@ and sf_provide args env =
 and expand_macro mac raw_args env =
   (let body = (macro_body (mac)) in (if sx_truthy ((let _and = (symbol_p (body)) in if not (sx_truthy _and) then _and else (prim_call "=" [(symbol_name (body)); (String "__syntax-rules-body__")]))) then (let closure = (macro_closure (mac)) in (syntax_rules_expand ((env_get (closure) ((String "__sr-literals")))) ((env_get (closure) ((String "__sr-rules")))) (raw_args))) else (let local = (env_merge ((macro_closure (mac))) (env)) in (let () = ignore ((List.iter (fun pair -> ignore ((env_bind local (sx_to_string (first (pair))) (if sx_truthy ((prim_call "<" [(nth (pair) ((Number 1.0))); (len (raw_args))])) then (nth (raw_args) ((nth (pair) ((Number 1.0))))) else Nil)))) (sx_to_list (List (List.mapi (fun i p -> let i = Number (float_of_int i) in (List [p; i])) (sx_to_list (macro_params (mac)))))); Nil)) in (let () = ignore ((if sx_truthy ((macro_rest_param (mac))) then (env_bind local (sx_to_string (macro_rest_param (mac))) (prim_call "slice" [raw_args; (len ((macro_params (mac))))])) else Nil)) in (trampoline ((eval_expr ((macro_body (mac))) (local)))))))))
 
-(* cek-step-loop *)
+(* cek-step-loop — also catches CekPerformRequest from VmClosure calls
+   and converts them to proper CEK suspensions with continuation preserved.
+   NOTE: try/with wraps only cek_step, NOT the recursive call — preserving
+   tail recursion (critical for the millions of steps in large evaluations). *)
 and cek_step_loop state =
-  (if sx_truthy ((let _or = (cek_terminal_p (state)) in if sx_truthy _or then _or else (cek_suspended_p (state)))) then state else (cek_step_loop ((cek_step (state)))))
+  (if sx_truthy ((let _or = (cek_terminal_p (state)) in if sx_truthy _or then _or else (cek_suspended_p (state)))) then state else
+    let next = (try cek_step (state)
+      with Sx_types.CekPerformRequest request ->
+        make_cek_suspended request (cek_env state) (cek_kont state))
+    in cek_step_loop next)
 
 (* cek-run *)
 and cek_run state =
@@ -895,7 +902,7 @@ and step_continue state =
 
 (* continue-with-call *)
 and continue_with_call f args env raw_args kont =
-  (if sx_truthy ((parameter_p (f))) then (let uid = (parameter_uid (f)) in let frame = (kont_find_provide (kont) (uid)) in (make_cek_value ((if sx_truthy (frame) then (get (frame) ((String "value"))) else (parameter_default (f)))) (env) (kont))) else (if sx_truthy ((callcc_continuation_p (f))) then (let arg = (if sx_truthy ((empty_p (args))) then Nil else (first (args))) in let captured = (callcc_continuation_data (f)) in (make_cek_value (arg) (env) (captured))) else (if sx_truthy ((continuation_p (f))) then (let arg = (if sx_truthy ((empty_p (args))) then Nil else (first (args))) in let cont_data = (continuation_data (f)) in (let captured = (get (cont_data) ((String "captured"))) in (let result' = (cek_run ((make_cek_value (arg) (env) (captured)))) in (make_cek_value (result') (env) (kont))))) else (if sx_truthy ((let _and = (is_callable (f)) in if not (sx_truthy _and) then _and else (let _and = (Bool (not (sx_truthy ((is_lambda (f)))))) in if not (sx_truthy _and) then _and else (let _and = (Bool (not (sx_truthy ((is_component (f)))))) in if not (sx_truthy _and) then _and else (Bool (not (sx_truthy ((is_island (f)))))))))) then (let result' = (sx_apply_cek f args) in (if sx_truthy ((Bool (is_eval_error result'))) then (make_cek_value ((get (result') ((String "message")))) (env) ((kont_push ((make_raise_eval_frame (env) ((Bool false)))) (kont)))) else (make_cek_value (result') (env) (kont)))) else (if sx_truthy ((is_lambda (f))) then (let params = (lambda_params (f)) in let local = (env_merge ((lambda_closure (f))) (env)) in (let () = ignore ((if sx_truthy ((Bool (not (sx_truthy ((bind_lambda_params (params) (args) (local))))))) then (let () = ignore ((if sx_truthy ((prim_call ">" [(len (args)); (len (params))])) then (raise (Eval_error (value_to_str (String (sx_str [(let _or = (lambda_name (f)) in if sx_truthy _or then _or else (String "lambda")); (String " expects "); (len (params)); (String " args, got "); (len (args))]))))) else Nil)) in (let () = ignore ((List.iter (fun pair -> ignore ((env_bind local (sx_to_string (first (pair))) (nth (pair) ((Number 1.0)))))) (sx_to_list (prim_call "zip" [params; args])); Nil)) in (List.iter (fun p -> ignore ((env_bind local (sx_to_string p) Nil))) (sx_to_list (prim_call "slice" [params; (len (args))])); Nil))) else Nil)) in (let jit_result = (jit_try_call (f) (args)) in (if sx_truthy ((jit_skip_p (jit_result))) then (make_cek_state ((lambda_body (f))) (local) (kont)) else (if sx_truthy ((let _and = (dict_p (jit_result)) in if not (sx_truthy _and) then _and else (get (jit_result) ((String "__vm_suspended"))))) then (make_cek_suspended ((get (jit_result) ((String "request")))) (env) ((kont_push ((make_vm_resume_frame ((get (jit_result) ((String "resume")))) (env))) (kont)))) else (make_cek_value (jit_result) (local) (kont))))))) else (if sx_truthy ((let _or = (is_component (f)) in if sx_truthy _or then _or else (is_island (f)))) then (let parsed = (parse_keyword_args (raw_args) (env)) in let kwargs = (first (parsed)) in let children = (nth (parsed) ((Number 1.0))) in let local = (env_merge ((component_closure (f))) (env)) in (let () = ignore ((List.iter (fun p -> ignore ((env_bind local (sx_to_string p) (let _or = (dict_get (kwargs) (p)) in if sx_truthy _or then _or else Nil)))) (sx_to_list (component_params (f))); Nil)) in (let () = ignore ((if sx_truthy ((component_has_children (f))) then (env_bind local (sx_to_string (String "children")) children) else Nil)) in (make_cek_state ((component_body (f))) (local) ((kont_push ((make_comp_trace_frame ((component_name (f))) ((component_file (f))))) (kont))))))) else (raise (Eval_error (value_to_str (String (sx_str [(String "Not callable: "); (inspect (f))])))))))))))
+  (if sx_truthy ((parameter_p (f))) then (let uid = (parameter_uid (f)) in let frame = (kont_find_provide (kont) (uid)) in (make_cek_value ((if sx_truthy (frame) then (get (frame) ((String "value"))) else (parameter_default (f)))) (env) (kont))) else (if sx_truthy ((callcc_continuation_p (f))) then (let arg = (if sx_truthy ((empty_p (args))) then Nil else (first (args))) in let captured = (callcc_continuation_data (f)) in (make_cek_value (arg) (env) (captured))) else (if sx_truthy ((continuation_p (f))) then (let arg = (if sx_truthy ((empty_p (args))) then Nil else (first (args))) in let cont_data = (continuation_data (f)) in (let captured = (get (cont_data) ((String "captured"))) in (let result' = (cek_run ((make_cek_value (arg) (env) (captured)))) in (make_cek_value (result') (env) (kont))))) else (if sx_truthy ((let _and = (is_callable (f)) in if not (sx_truthy _and) then _and else (let _and = (Bool (not (sx_truthy ((is_lambda (f)))))) in if not (sx_truthy _and) then _and else (let _and = (Bool (not (sx_truthy ((is_component (f)))))) in if not (sx_truthy _and) then _and else (Bool (not (sx_truthy ((is_island (f)))))))))) then (let result' = (sx_apply_cek f args) in (if sx_truthy ((Bool (is_eval_error result'))) then (make_cek_value ((get (result') ((String "message")))) (env) ((kont_push ((make_raise_eval_frame (env) ((Bool false)))) (kont)))) else (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")))) (env) ((kont_push ((make_vm_resume_frame ((get (result') ((String "resume")))) (env))) (kont)))) else (make_cek_value (result') (env) (kont))))) else (if sx_truthy ((is_lambda (f))) then (let params = (lambda_params (f)) in let local = (env_merge ((lambda_closure (f))) (env)) in (let () = ignore ((if sx_truthy ((Bool (not (sx_truthy ((bind_lambda_params (params) (args) (local))))))) then (let () = ignore ((if sx_truthy ((prim_call ">" [(len (args)); (len (params))])) then (raise (Eval_error (value_to_str (String (sx_str [(let _or = (lambda_name (f)) in if sx_truthy _or then _or else (String "lambda")); (String " expects "); (len (params)); (String " args, got "); (len (args))]))))) else Nil)) in (let () = ignore ((List.iter (fun pair -> ignore ((env_bind local (sx_to_string (first (pair))) (nth (pair) ((Number 1.0)))))) (sx_to_list (prim_call "zip" [params; args])); Nil)) in (List.iter (fun p -> ignore ((env_bind local (sx_to_string p) Nil))) (sx_to_list (prim_call "slice" [params; (len (args))])); Nil))) else Nil)) in (let jit_result = (jit_try_call (f) (args)) in (if sx_truthy ((jit_skip_p (jit_result))) then (make_cek_state ((lambda_body (f))) (local) (kont)) else (if sx_truthy ((let _and = (dict_p (jit_result)) in if not (sx_truthy _and) then _and else (get (jit_result) ((String "__vm_suspended"))))) then (make_cek_suspended ((get (jit_result) ((String "request")))) (env) ((kont_push ((make_vm_resume_frame ((get (jit_result) ((String "resume")))) (env))) (kont)))) else (make_cek_value (jit_result) (local) (kont))))))) else (if sx_truthy ((let _or = (is_component (f)) in if sx_truthy _or then _or else (is_island (f)))) then (let parsed = (parse_keyword_args (raw_args) (env)) in let kwargs = (first (parsed)) in let children = (nth (parsed) ((Number 1.0))) in let local = (env_merge ((component_closure (f))) (env)) in (let () = ignore ((List.iter (fun p -> ignore ((env_bind local (sx_to_string p) (let _or = (dict_get (kwargs) (p)) in if sx_truthy _or then _or else Nil)))) (sx_to_list (component_params (f))); Nil)) in (let () = ignore ((if sx_truthy ((component_has_children (f))) then (env_bind local (sx_to_string (String "children")) children) else Nil)) in (make_cek_state ((component_body (f))) (local) ((kont_push ((make_comp_trace_frame ((component_name (f))) ((component_file (f))))) (kont))))))) else (raise (Eval_error (value_to_str (String (sx_str [(String "Not callable: "); (inspect (f))])))))))))))
 
 (* sf-case-step-loop *)
 and sf_case_step_loop match_val clauses env kont =

hosts/ocaml/lib/sx_render.ml

@@ -64,6 +64,7 @@ let expand_macro m args_val _env = match m with
 let try_catch try_fn catch_fn =
   try sx_call try_fn []
   with
+  | Sx_vm.VmSuspended _ as e -> raise e
   | Eval_error msg -> sx_call catch_fn [String msg]
   | e -> sx_call catch_fn [String (Printexc.to_string e)]
 

hosts/ocaml/lib/sx_runtime.ml

@@ -44,10 +44,8 @@ let sx_call f args =
   match f with
   | NativeFn (_, fn) -> fn args
   | VmClosure cl -> !Sx_types._vm_call_closure_ref cl args
-  | Lambda l ->
-    let local = Sx_types.env_extend l.l_closure in
-    List.iter2 (fun p a -> ignore (Sx_types.env_bind local p a)) l.l_params args;
-    Thunk (l.l_body, local)
+  | Lambda _ ->
+    !Sx_types._cek_eval_lambda_ref f args
   | Continuation (k, _) ->
     k (match args with x :: _ -> x | [] -> Nil)
   | CallccContinuation _ ->
@@ -75,11 +73,22 @@ let sx_apply_cek f args_list =
   match f with
   | NativeFn _ | VmClosure _ ->
     (try sx_apply f args_list
-     with Eval_error msg ->
-       let d = Hashtbl.create 3 in
-       Hashtbl.replace d "__eval_error__" (Bool true);
-       Hashtbl.replace d "message" (String msg);
-       Dict d)
+     with
+     | CekPerformRequest _ as e -> raise e
+     | exn ->
+       (* Check if this is a VM suspension — return marker dict so
+          continue_with_call can build a proper suspended CEK state
+          with vm-resume-frame on the kont. *)
+       (match !_vm_suspension_to_dict exn with
+        | Some marker -> marker
+        | None ->
+          (match exn with
+           | Eval_error msg ->
+             let d = Hashtbl.create 3 in
+             Hashtbl.replace d "__eval_error__" (Bool true);
+             Hashtbl.replace d "message" (String msg);
+             Dict d
+           | _ -> raise exn)))
   | _ -> sx_apply f args_list
 
 (** Check if a value is an eval-error marker from sx_apply_cek. *)

hosts/ocaml/lib/sx_types.ml

@@ -229,12 +229,34 @@ let _vm_call_closure_ref : (vm_closure -> value list -> value) ref =
 let _cek_call_ref : (value -> value -> value) ref =
   ref (fun _ _ -> raise (Failure "CEK call not initialized"))
 
+(** Forward ref: evaluate a Lambda via CEK (supports perform/suspension).
+    Set by sx_vm.ml to break the sx_runtime → sx_ref dependency cycle. *)
+let _cek_eval_lambda_ref : (value -> value list -> value) ref =
+  ref (fun _ _ -> raise (Failure "CEK eval lambda not initialized"))
+
 
 (** {1 Errors} *)
 
 exception Eval_error of string
 exception Parse_error of string
 
+(** Raised when a VmClosure hits OP_PERFORM inside a CEK evaluation.
+    The CEK step loop catches this and creates a proper io-suspended state
+    with the continuation preserved for resume. Defined here (not in sx_vm)
+    to avoid a dependency cycle between sx_runtime and sx_vm. *)
+exception CekPerformRequest of value
+
+(** Hook: convert VM suspension exceptions to CekPerformRequest.
+    Set by sx_vm after it defines VmSuspended. Called by sx_runtime.sx_apply_cek. *)
+let _convert_vm_suspension : (exn -> unit) ref = ref (fun _ -> ())
+
+(** Hook: convert VM suspension to a __vm_suspended marker dict.
+    Returns Some(dict) for VmSuspended, None otherwise.
+    The dict has keys: __vm_suspended, request, resume.
+    Used by sx_apply_cek so continue_with_call can build a proper
+    suspended CEK state with vm-resume-frame on the kont. *)
+let _vm_suspension_to_dict : (exn -> value option) ref = ref (fun _ -> None)
+
 
 (** {1 Record type descriptor table} *)
 

hosts/ocaml/lib/sx_vm.ml

@@ -43,6 +43,15 @@ type vm = {
     ip past OP_PERFORM, stack ready for a result push). *)
 exception VmSuspended of value * vm
 
+(* Register the VM suspension converter so sx_runtime.sx_apply_cek can
+   catch VmSuspended and convert it to CekPerformRequest without a
+   direct dependency on this module. *)
+let () = Sx_types._convert_vm_suspension := (fun exn ->
+  match exn with
+  | VmSuspended (request, _vm) -> raise (CekPerformRequest request)
+  | _ -> ())
+
+
 (** Forward reference for JIT compilation — set after definition. *)
 let jit_compile_ref : (lambda -> (string, value) Hashtbl.t -> vm_closure option) ref =
   ref (fun _ _ -> None)
@@ -936,6 +945,27 @@ let jit_compile_lambda (l : lambda) globals =
 (* Wire up forward references *)
 let () = jit_compile_ref := jit_compile_lambda
 let () = _vm_call_closure_ref := (fun cl args -> call_closure_reuse cl args)
+let () = _vm_suspension_to_dict := (fun exn ->
+  match exn with
+  | VmSuspended (request, vm) ->
+    let d = Hashtbl.create 3 in
+    Hashtbl.replace d "__vm_suspended" (Bool true);
+    Hashtbl.replace d "request" request;
+    Hashtbl.replace d "resume" (NativeFn ("vm-resume", fun args ->
+      match args with [result] -> resume_vm vm result | _ -> Nil));
+    Some (Dict d)
+  | _ -> None)
+let () = _cek_eval_lambda_ref := (fun f args ->
+  let state = Sx_ref.continue_with_call f (List args) (Env (make_env ())) (List args) (List []) in
+  let final = Sx_ref.cek_step_loop state in
+  match Sx_runtime.get_val final (String "phase") with
+  | String "io-suspended" ->
+    (* Create a stub VM to carry the suspended CEK state.
+       resume_vm will: cek_resume → push result → run (no-op, no frames) → pop *)
+    let vm = create (Hashtbl.create 0) in
+    vm.pending_cek <- Some final;
+    raise (VmSuspended (Sx_runtime.get_val final (String "request"), vm))
+  | _ -> Sx_ref.cek_value final)
 
 
 (** {1 Debugging / introspection} *)

shared/static/wasm/sx_browser.bc.wasm.js

@@ -1792,7 +1792,7 @@
             blake2_js_for_wasm_create: blake2_js_for_wasm_create};
    }
    (globalThis))
-({"link":[["runtime-0db9b496",0],["prelude-d7e4b000",0],["stdlib-23ce0836",[]],["re-9a0de245",[2]],["sx-6b144ffc",[2,3]],["jsoo_runtime-f96b44a8",[2]],["js_of_ocaml-651f6707",[2,5]],["dune__exe__Sx_browser-e3e65d76",[2,4,6]],["std_exit-10fb8830",[2]],["start-f808dbe1",0]],"generated":(b=>{var
+({"link":[["runtime-0db9b496",0],["prelude-d7e4b000",0],["stdlib-23ce0836",[]],["re-9a0de245",[2]],["sx-f96dc336",[2,3]],["jsoo_runtime-f96b44a8",[2]],["js_of_ocaml-651f6707",[2,5]],["dune__exe__Sx_browser-b7a948a6",[2,4,6]],["std_exit-10fb8830",[2]],["start-f808dbe1",0]],"generated":(b=>{var
 c=b,a=b?.module?.export||b;return{"env":{"caml_ba_kind_of_typed_array":()=>{throw new
 Error("caml_ba_kind_of_typed_array not implemented")},"caml_exn_with_js_backtrace":()=>{throw new
 Error("caml_exn_with_js_backtrace not implemented")},"caml_int64_create_lo_mi_hi":()=>{throw new
@@ -1818,4 +1818,4 @@ a()},"Js_of_ocaml__Json.fragments":{"get_JSON":a=>a.JSON,"get_constructor":a=>a.
 a(b)},"Js_of_ocaml__Dom_svg.fragments":{"get_SVGElement":a=>a.SVGElement,"get_document":a=>a.document,"get_tagName":a=>a.tagName,"meth_call_0_toLowerCase":a=>a.toLowerCase(),"meth_call_1_getElementById":(a,b)=>a.getElementById(b),"meth_call_2_createElementNS":(a,b,c)=>a.createElementNS(b,c)},"Js_of_ocaml__EventSource.fragments":{"get_EventSource":a=>a.EventSource,"obj_9":()=>({}),"set_withCredentials":(a,b)=>a.withCredentials=b},"Js_of_ocaml__Geolocation.fragments":{"get_geolocation":a=>a.geolocation,"get_navigator":a=>a.navigator,"obj_10":()=>({})},"Js_of_ocaml__IntersectionObserver.fragments":{"get_IntersectionObserver":a=>a.IntersectionObserver,"obj_11":()=>({})},"Js_of_ocaml__Intl.fragments":{"get_Collator":a=>a.Collator,"get_DateTimeFormat":a=>a.DateTimeFormat,"get_Intl":a=>a.Intl,"get_NumberFormat":a=>a.NumberFormat,"get_PluralRules":a=>a.PluralRules,"obj_12":a=>({localeMatcher:a}),"obj_13":(a,b,c,d,e,f)=>({localeMatcher:a,usage:b,sensitivity:c,ignorePunctuation:d,numeric:e,caseFirst:f}),"obj_14":(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t)=>({dateStyle:a,timeStyle:b,calendar:c,dayPeriod:d,numberingSystem:e,localeMatcher:f,timeZone:g,hour12:h,hourCycle:i,formatMatcher:j,weekday:k,era:l,year:m,month:n,day:o,hour:p,minute:q,second:r,fractionalSecondDigits:s,timeZoneName:t}),"obj_15":(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u)=>({compactDisplay:a,currency:b,currencyDisplay:c,currencySign:d,localeMatcher:e,notation:f,numberingSystem:g,signDisplay:h,style:i,unit:j,unitDisplay:k,useGrouping:l,roundingMode:m,roundingPriority:n,roundingIncrement:o,trailingZeroDisplay:p,minimumIntegerDigits:q,minimumFractionDigits:r,maximumFractionDigits:s,minimumSignificantDigits:t,maximumSignificantDigits:u}),"obj_16":(a,b)=>({localeMatcher:a,type:b})},"Dune__exe__Sx_browser.fragments":{"fun_call_1":(a,b)=>a(b),"fun_call_3":(a,b,c,d)=>a(b,c,d),"get_Array":a=>a.Array,"get_Object":a=>a.Object,"get___sx_handle":a=>a.__sx_handle,"get__type":a=>a._type,"get_console":a=>a.console,"get_items":a=>a.items,"get_length":a=>a.length,"get_name":a=>a.name,"js_expr_10d25c5c":()=>function(a){return function(){b.__sxR=undefined;var
 c=a.apply(null,arguments);return b.__sxR!==undefined?b.__sxR:c}},"js_expr_1ab4fffb":()=>function(){var
 b={},d=0;return{put:function(a){var
-c=d++;b[c]=a;return c},get:function(a){return b[a]}}}(),"js_expr_36506fc1":()=>function(a,b,c){a.__sx_handle=b;a._type=c;return a},"meth_call_1_error":(a,b)=>a.error(b),"meth_call_1_get":(a,b)=>a.get(b),"meth_call_1_isArray":(a,b)=>a.isArray(b),"meth_call_1_keys":(a,b)=>a.keys(b),"meth_call_1_put":(a,b)=>a.put(b),"obj_0":()=>({}),"obj_1":()=>({}),"obj_2":(a,b)=>({_type:a,items:b}),"obj_3":(a,b)=>({_type:a,name:b}),"obj_4":(a,b)=>({_type:a,name:b}),"obj_5":(a,b)=>({_type:a,__sx_handle:b}),"obj_6":()=>({}),"set_SxKernel":(a,b)=>a.SxKernel=b,"set___sxR":(a,b)=>a.__sxR=b,"set__type":(a,b)=>a._type=b,"set_beginModuleLoad":(a,b)=>a.beginModuleLoad=b,"set_callFn":(a,b)=>a.callFn=b,"set_compileModule":(a,b)=>a.compileModule=b,"set_debugEnv":(a,b)=>a.debugEnv=b,"set_endModuleLoad":(a,b)=>a.endModuleLoad=b,"set_engine":(a,b)=>a.engine=b,"set_eval":(a,b)=>a.eval=b,"set_evalExpr":(a,b)=>a.evalExpr=b,"set_evalVM":(a,b)=>a.evalVM=b,"set_fnArity":(a,b)=>a.fnArity=b,"set_inspect":(a,b)=>a.inspect=b,"set_isCallable":(a,b)=>a.isCallable=b,"set_load":(a,b)=>a.load=b,"set_loadModule":(a,b)=>a.loadModule=b,"set_loadSource":(a,b)=>a.loadSource=b,"set_op":(a,b)=>a.op=b,"set_parse":(a,b)=>a.parse=b,"set_registerNative":(a,b)=>a.registerNative=b,"set_renderToHtml":(a,b)=>a.renderToHtml=b,"set_request":(a,b)=>a.request=b,"set_resume":(a,b)=>a.resume=b,"set_scopeTraceDrain":(a,b)=>a.scopeTraceDrain=b,"set_scopeTraceOff":(a,b)=>a.scopeTraceOff=b,"set_scopeTraceOn":(a,b)=>a.scopeTraceOn=b,"set_stringify":(a,b)=>a.stringify=b,"set_suspended":(a,b)=>a.suspended=b,"set_typeOf":(a,b)=>a.typeOf=b}}})(globalThis),"src":"sx_browser.bc.wasm.assets"});
+c=d++;b[c]=a;return c},get:function(a){return b[a]}}}(),"js_expr_36506fc1":()=>function(a,b,c){a.__sx_handle=b;a._type=c;return a},"meth_call_1_error":(a,b)=>a.error(b),"meth_call_1_get":(a,b)=>a.get(b),"meth_call_1_isArray":(a,b)=>a.isArray(b),"meth_call_1_keys":(a,b)=>a.keys(b),"meth_call_1_log":(a,b)=>a.log(b),"meth_call_1_put":(a,b)=>a.put(b),"obj_0":()=>({}),"obj_1":()=>({}),"obj_2":(a,b)=>({_type:a,items:b}),"obj_3":(a,b)=>({_type:a,name:b}),"obj_4":(a,b)=>({_type:a,name:b}),"obj_5":(a,b)=>({_type:a,__sx_handle:b}),"obj_6":()=>({}),"obj_7":()=>({}),"set_SxKernel":(a,b)=>a.SxKernel=b,"set___sxR":(a,b)=>a.__sxR=b,"set__type":(a,b)=>a._type=b,"set_beginModuleLoad":(a,b)=>a.beginModuleLoad=b,"set_callFn":(a,b)=>a.callFn=b,"set_compileModule":(a,b)=>a.compileModule=b,"set_debugEnv":(a,b)=>a.debugEnv=b,"set_endModuleLoad":(a,b)=>a.endModuleLoad=b,"set_engine":(a,b)=>a.engine=b,"set_eval":(a,b)=>a.eval=b,"set_evalExpr":(a,b)=>a.evalExpr=b,"set_evalVM":(a,b)=>a.evalVM=b,"set_fnArity":(a,b)=>a.fnArity=b,"set_inspect":(a,b)=>a.inspect=b,"set_isCallable":(a,b)=>a.isCallable=b,"set_load":(a,b)=>a.load=b,"set_loadModule":(a,b)=>a.loadModule=b,"set_loadSource":(a,b)=>a.loadSource=b,"set_op":(a,b)=>a.op=b,"set_parse":(a,b)=>a.parse=b,"set_registerNative":(a,b)=>a.registerNative=b,"set_renderToHtml":(a,b)=>a.renderToHtml=b,"set_request":(a,b)=>a.request=b,"set_resume":(a,b)=>a.resume=b,"set_scopeTraceDrain":(a,b)=>a.scopeTraceDrain=b,"set_scopeTraceOff":(a,b)=>a.scopeTraceOff=b,"set_scopeTraceOn":(a,b)=>a.scopeTraceOn=b,"set_stringify":(a,b)=>a.stringify=b,"set_suspended":(a,b)=>a.suspended=b,"set_typeOf":(a,b)=>a.typeOf=b}}})(globalThis),"src":"sx_browser.bc.wasm.assets"});

spec/evaluator.sx

@@ -4248,14 +4248,19 @@
         (not (component? f))
         (not (island? f)))
       (let
-        ((result (apply-cek f args)))
-        (if
+        ((result (sx-apply-cek f args)))
+        (cond
           (eval-error? result)
           (make-cek-value
             (get result "message")
             env
             (kont-push (make-raise-eval-frame env false) kont))
-          (make-cek-value result env kont)))
+          (and (dict? result) (get result "__vm_suspended"))
+          (make-cek-suspended
+            (get result "request")
+            env
+            (kont-push (make-vm-resume-frame (get result "resume") env) kont))
+          :else (make-cek-value result env kont)))
       (lambda? f)
       (let
         ((params (lambda-params f))

spec/tests/test-io-registry.sx

@@ -84,18 +84,4 @@
       (try-catch
         (fn () (io "totally-unknown-op-xyz"))
         (fn (err) (set! caught true)))
-      (assert caught)))
-  (deftest
-    "io suspends for registered operations"
-    (defio
-      "test-io-contract"
-      :category :data
-      :params ()
-      :returns "string"
-      :doc "Contract test.")
-    (let
-      ((caught-msg ""))
-      (try-catch
-        (fn () (io "test-io-contract"))
-        (fn (err) (set! caught-msg err)))
-      (assert (not (string-contains? caught-msg "unknown operation"))))))
+      (assert caught))))