Compiler: dict destructuring in let, paren-aware library stripping — 31/31 sxbc

compile-let now handles dict destructuring patterns:
(let {:key1 var1 :key2 var2} source body). This unblocked core-signals.sx
(deref uses dict destructuring) which was the sole bytecode skip.

Rewrote stripLibraryWrapper from line-based to paren-aware extraction.
The old regex missed (define-library on its own line (no trailing space),
silently passing the full wrapper to the compiler.

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

shared/static/wasm/sx/compiler.sx

@@ -589,24 +589,64 @@
                   (list (list (make-symbol loop-name) lambda-expr)))
                 (call-expr (cons (make-symbol loop-name) inits)))
               (compile-letrec em (list letrec-bindings call-expr) scope tail?)))
-          (let
-            ((bindings (first args))
-              (body (rest args))
-              (let-scope (make-scope scope)))
-            (dict-set! let-scope "next-slot" (get scope "next-slot"))
-            (for-each
-              (fn
-                (binding)
-                (let
-                  ((name (if (= (type-of (first binding)) "symbol") (symbol-name (first binding)) (first binding)))
-                    (value (nth binding 1)))
-                  (compile-expr em value let-scope false)
+          (if
+            (dict? (first args))
+            (let
+              ((pattern (first args))
+                (source-expr (nth args 1))
+                (body (slice args 2))
+                (let-scope (make-scope scope)))
+              (dict-set! let-scope "next-slot" (get scope "next-slot"))
+              (compile-expr em source-expr let-scope false)
+              (let
+                ((temp-slot (scope-define-local let-scope "__dict_src")))
+                (emit-op em 17)
+                (emit-byte em temp-slot)
+                (for-each
+                  (fn
+                    (k)
+                    (let
+                      ((var-name (get pattern k))
+                        (key-str
+                          (if
+                            (= (type-of k) "keyword")
+                            (keyword-name k)
+                            (str k))))
+                      (emit-op em 16)
+                      (emit-byte em temp-slot)
+                      (let
+                        ((key-idx (pool-add (get em "pool") key-str)))
+                        (emit-op em 2)
+                        (emit-u16 em key-idx))
+                      (let
+                        ((get-idx (pool-add (get em "pool") "get")))
+                        (emit-op em 10)
+                        (emit-u16 em get-idx)
+                        (emit-byte em 2))
+                      (let
+                        ((slot (scope-define-local let-scope (if (= (type-of var-name) "symbol") (symbol-name var-name) var-name))))
+                        (emit-op em 17)
+                        (emit-byte em slot))))
+                  (keys pattern))
+                (compile-begin em body let-scope tail?)))
+            (let
+              ((bindings (first args))
+                (body (rest args))
+                (let-scope (make-scope scope)))
+              (dict-set! let-scope "next-slot" (get scope "next-slot"))
+              (for-each
+                (fn
+                  (binding)
                   (let
-                    ((slot (scope-define-local let-scope name)))
-                    (emit-op em 17)
-                    (emit-byte em slot))))
-              bindings)
-            (compile-begin em body let-scope tail?)))))
+                    ((name (if (= (type-of (first binding)) "symbol") (first binding) (make-symbol (first binding))))
+                      (value (nth binding 1)))
+                    (compile-expr em value let-scope false)
+                    (let
+                      ((slot (scope-define-local let-scope (symbol-name name))))
+                      (emit-op em 17)
+                      (emit-byte em slot))))
+                bindings)
+              (compile-begin em body let-scope tail?))))))
     (define
       compile-letrec
       (fn

shared/static/wasm/sx/signals.sxbc

@@ -1,3 +1,3 @@
 (sxbc 1 "232c1519553b1d5f"
   (code
-    :constants ({:library (sx dom) :op "import"} {:library (sx browser) :op "import"} "with-marsh-scope" {:upvalue-count 0 :arity 2 :constants ("list" "with-island-scope" {:upvalue-count 1 :arity 1 :constants ("append!") :bytecode (18 0 16 0 52 0 0 2 50)} "dom-set-data" "sx-marsh-disposers") :bytecode (52 0 0 0 17 2 20 1 0 51 2 0 1 2 16 1 48 2 5 20 3 0 16 0 1 4 0 16 2 49 3 50)} "dispose-marsh-scope" {:upvalue-count 0 :arity 1 :constants ("dom-get-data" "sx-marsh-disposers" "for-each" {:upvalue-count 0 :arity 1 :constants ("cek-call") :bytecode (16 0 2 52 0 0 2 50)} "dom-set-data") :bytecode (20 0 0 16 0 1 1 0 48 2 17 1 16 1 33 24 0 51 3 0 16 1 52 2 0 2 5 20 4 0 16 0 1 1 0 2 49 3 32 1 0 2 50)} "emit-event" {:upvalue-count 0 :arity 3 :constants ("dom-dispatch") :bytecode (20 0 0 16 0 16 1 16 2 49 3 50)} "on-event" {:upvalue-count 0 :arity 3 :constants ("dom-on") :bytecode (20 0 0 16 0 16 1 16 2 49 3 50)} "bridge-event" {:upvalue-count 0 :arity 4 :constants ("effect" {:upvalue-count 4 :arity 0 :constants ("dom-on" {:upvalue-count 2 :arity 1 :constants ("event-detail" "cek-call" "list" "reset!") :bytecode (20 0 0 16 0 48 1 17 1 18 0 33 15 0 18 0 16 1 52 2 0 1 52 1 0 2 32 2 0 16 1 17 2 20 3 0 18 1 16 2 49 2 50)}) :bytecode (20 0 0 18 0 18 1 51 1 0 0 2 0 3 48 3 17 0 16 0 50)}) :bytecode (20 0 0 51 1 0 1 0 1 1 1 3 1 2 49 1 50)} "resource" {:upvalue-count 0 :arity 1 :constants ("signal" "dict" "loading" "data" "error" "promise-then" "cek-call" {:upvalue-count 1 :arity 1 :constants ("reset!" "dict" "loading" "data" "error") :bytecode (20 0 0 18 0 1 2 0 4 1 3 0 16 0 1 4 0 2 52 1 0 6 49 2 50)} {:upvalue-count 1 :arity 1 :constants ("reset!" "dict" "loading" "data" "error") :bytecode (20 0 0 18 0 1 2 0 4 1 3 0 2 1 4 0 16 0 52 1 0 6 49 2 50)}) :bytecode (20 0 0 1 2 0 3 1 3 0 2 1 4 0 2 52 1 0 6 48 1 17 1 20 5 0 16 0 2 52 6 0 2 51 7 0 1 1 51 8 0 1 1 48 3 5 16 1 50)} {:library (sx signals-web) :op "import"}) :bytecode (1 0 0 112 5 1 1 0 112 5 51 3 0 128 2 0 5 51 5 0 128 4 0 5 51 7 0 128 6 0 5 51 9 0 128 8 0 5 51 11 0 128 10 0 5 51 13 0 128 12 0 5 1 14 0 112 50)))
+    :constants ("with-marsh-scope" {:upvalue-count 0 :arity 2 :constants ("list" "with-island-scope" {:upvalue-count 1 :arity 1 :constants ("append!") :bytecode (18 0 16 0 52 0 0 2 50)} "dom-set-data" "sx-marsh-disposers") :bytecode (52 0 0 0 17 2 20 1 0 51 2 0 1 2 16 1 48 2 5 20 3 0 16 0 1 4 0 16 2 49 3 50)} "dispose-marsh-scope" {:upvalue-count 0 :arity 1 :constants ("dom-get-data" "sx-marsh-disposers" "for-each" {:upvalue-count 0 :arity 1 :constants ("cek-call") :bytecode (16 0 2 52 0 0 2 50)} "dom-set-data") :bytecode (20 0 0 16 0 1 1 0 48 2 17 1 16 1 33 24 0 51 3 0 16 1 52 2 0 2 5 20 4 0 16 0 1 1 0 2 49 3 32 1 0 2 50)} "emit-event" {:upvalue-count 0 :arity 3 :constants ("dom-dispatch") :bytecode (20 0 0 16 0 16 1 16 2 49 3 50)} "on-event" {:upvalue-count 0 :arity 3 :constants ("dom-on") :bytecode (20 0 0 16 0 16 1 16 2 49 3 50)} "bridge-event" {:upvalue-count 0 :arity 4 :constants ("effect" {:upvalue-count 4 :arity 0 :constants ("dom-on" {:upvalue-count 2 :arity 1 :constants ("event-detail" "cek-call" "list" "reset!") :bytecode (20 0 0 16 0 48 1 17 1 18 0 33 15 0 18 0 16 1 52 2 0 1 52 1 0 2 32 2 0 16 1 17 2 20 3 0 18 1 16 2 49 2 50)}) :bytecode (20 0 0 18 0 18 1 51 1 0 0 2 0 3 48 3 17 0 16 0 50)}) :bytecode (20 0 0 51 1 0 1 0 1 1 1 3 1 2 49 1 50)} "resource" {:upvalue-count 0 :arity 1 :constants ("signal" "dict" "loading" "data" "error" "promise-then" "cek-call" {:upvalue-count 1 :arity 1 :constants ("reset!" "dict" "loading" "data" "error") :bytecode (20 0 0 18 0 1 2 0 4 1 3 0 16 0 1 4 0 2 52 1 0 6 49 2 50)} {:upvalue-count 1 :arity 1 :constants ("reset!" "dict" "loading" "data" "error") :bytecode (20 0 0 18 0 1 2 0 4 1 3 0 2 1 4 0 16 0 52 1 0 6 49 2 50)}) :bytecode (20 0 0 1 2 0 3 1 3 0 2 1 4 0 2 52 1 0 6 48 1 17 1 20 5 0 16 0 2 52 6 0 2 51 7 0 1 1 51 8 0 1 1 48 3 5 16 1 50)} {:library (sx signals-web) :op "import"}) :bytecode (51 1 0 128 0 0 5 51 3 0 128 2 0 5 51 5 0 128 4 0 5 51 7 0 128 6 0 5 51 9 0 128 8 0 5 51 11 0 128 10 0 5 1 12 0 112 50)))

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-42ed14c8",[2,3]],["jsoo_runtime-f96b44a8",[2]],["js_of_ocaml-651f6707",[2,5]],["dune__exe__Sx_browser-acaac3c1",[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-7ec49d05",[2,3]],["jsoo_runtime-f96b44a8",[2]],["js_of_ocaml-651f6707",[2,5]],["dune__exe__Sx_browser-acaac3c1",[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