Fix Pretext island: library functions inside define-library begin block

Root cause: sx_insert_near placed break-lines-greedy, pretext-position-line,
pretext-layout-lines OUTSIDE the define-library begin block. The bytecode
compiler only compiles forms inside begin as STORE_GLOBAL — forms outside
are invisible to the browser VM.

Fix: moved all function definitions inside (begin ...) of (define-library).
Bytecode now includes all 17 functions (11K compiled, was 9K).

Browser load-sxbc: simplified VmSuspended handling — just catch and
continue, since STORE_GLOBAL ops already ran before the import OP_PERFORM.
sync_vm_to_env copies them to global_env.

Island now calls break-lines and pretext-layout-lines from bytecode-compiled
library — runs on VM, not CEK interpreter.

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

hosts/ocaml/browser/sx_browser.ml

@@ -688,42 +688,12 @@ let () =
       (* Use execute_module_safe to handle import suspension.
          Libraries compiled from define-library + import emit OP_PERFORM
          at the end; we catch and resolve the import inline. *)
-      let run_module c =
-        let rec handle_result r =
-          match r with
-          | Ok _result -> ()
-          | Error (request, saved_vm) ->
-            (* Import suspension — library body already ran and registered.
-               Copy exports to global env, then resume the VM. *)
-            let lib_spec = Sx_runtime.get_val request (String "library") in
-            (try ignore (Sx_ref.bind_import_set lib_spec (Env global_env))
-             with _ -> ());
-            let next = try Ok (Sx_vm.resume_vm saved_vm Nil)
-              with Sx_vm.VmSuspended (req2, vm2) -> Error (req2, vm2) in
-            handle_result next
-        in
-        handle_result (Sx_vm.execute_module_safe c _vm_globals)
-      in
-      run_module code;
-      sync_vm_to_env ();
-      (* After loading, copy any new library exports to global env.
-         define-library registers exports in _library_registry_;
-         the import OP_PERFORM can't execute bind_import_set in bytecode,
-         so we manually copy exports that aren't yet in global_env. *)
-      (match Sx_ref._library_registry_ with
-       | Dict registry ->
-         Hashtbl.iter (fun _key entry ->
-           (match Sx_runtime.get_val entry (String "exports") with
-            | Dict exports ->
-              Hashtbl.iter (fun name value ->
-                if not (Sx_types.env_has global_env name) then begin
-                  ignore (Sx_types.env_bind global_env name value);
-                  Hashtbl.replace _vm_globals name value
-                end
-              ) exports
-            | _ -> ())
-         ) registry
+      (try
+        ignore (Sx_vm.execute_module code _vm_globals)
+       with
+       | Sx_vm.VmSuspended _ -> ()  (* Import suspension — defines already in globals *)
        | _ -> ());
+      sync_vm_to_env ();
       Number (float_of_int (Hashtbl.length _vm_globals))
     | _ -> raise (Eval_error "load-sxbc: expected (sxbc version hash (code ...))"));
 

lib/text-layout.sx

@@ -13,21 +13,6 @@
 ;; Knuth-Plass optimal line breaking (DP over break candidates).
 ;; Liang's hyphenation (trie over character patterns).
 
-(define
-  pretext-position-line
-  (fn
-    (words widths gap-w)
-    (let
-      loop
-      ((i 0) (x 0) (acc (list)))
-      (if
-        (>= i (len words))
-        acc
-        (loop
-          (+ i 1)
-          (+ x (nth widths i) gap-w)
-          (append acc (list {:width (nth widths i) :x x :word (nth words i)})))))))
-
 (define-library
   (sx text-layout)
   (export
@@ -149,6 +134,32 @@
               (let
                 ((ends (append (rest starts) (list n))))
                 (map-indexed (fn (i s) (list s (nth ends i))) starts)))))))
+    (define
+      break-lines-greedy
+      (fn
+        (widths space-width max-width)
+        (let
+          ((n (len widths)))
+          (if
+            (= n 0)
+            (list)
+            (let
+              ((lines (list)) (start 0) (used 0))
+              (for-each
+                (fn
+                  (i)
+                  (let
+                    ((w (nth widths i))
+                      (needed (if (= i start) w (+ used space-width w))))
+                    (if
+                      (and (> needed max-width) (not (= i start)))
+                      (do
+                        (set! lines (append lines (list (list start i))))
+                        (set! start i)
+                        (set! used w))
+                      (set! used needed))))
+                (range n))
+              (append lines (list (list start n))))))))
     (define
       position-line
       (fn
@@ -181,6 +192,45 @@
                   (line-widths (slice widths start end)))
                 (position-line line-words line-widths space-width x0 y))))
           line-ranges)))
+    (define
+      pretext-position-line
+      (fn
+        (words widths gap-w)
+        (let
+          loop
+          ((i 0) (x 0) (acc (list)))
+          (if
+            (>= i (len words))
+            acc
+            (loop
+              (+ i 1)
+              (+ x (nth widths i) gap-w)
+              (append acc (list {:width (nth widths i) :x x :word (nth words i)})))))))
+    (define
+      pretext-layout-lines
+      (fn
+        (words widths ranges space-width max-width line-height)
+        (let
+          ((n-lines (len ranges)))
+          (map
+            (fn
+              (line-idx)
+              (let
+                ((range (nth ranges line-idx))
+                  (y (* line-idx line-height)))
+                (let
+                  ((start (first range)) (end (nth range 1)))
+                  (let
+                    ((lw (slice words start end))
+                      (lwid (slice widths start end)))
+                    (let
+                      ((total-w (reduce + 0 lwid))
+                        (n-gaps (max 1 (- (len lw) 1)))
+                        (is-last (= line-idx (- n-lines 1))))
+                      (let
+                        ((gap (if is-last space-width (/ (- max-width total-w) n-gaps))))
+                        {:y y :words (pretext-position-line lw lwid gap)}))))))
+            (range n-lines)))))
     (define
       make-hyphenation-trie
       (fn
@@ -327,31 +377,4 @@
             (lh (or line-height 1.4)))
           (layout-paragraph words f s w lh))))))
 
-(define
-  break-lines-greedy
-  (fn
-    (widths space-width max-width)
-    (let
-      ((n (len widths)))
-      (if
-        (= n 0)
-        (list)
-        (let
-          ((lines (list)) (start 0) (used 0))
-          (for-each
-            (fn
-              (i)
-              (let
-                ((w (nth widths i))
-                  (needed (if (= i start) w (+ used space-width w))))
-                (if
-                  (and (> needed max-width) (not (= i start)))
-                  (do
-                    (set! lines (append lines (list (list start i))))
-                    (set! start i)
-                    (set! used w))
-                  (set! used needed))))
-            (range n))
-          (append lines (list (list start n))))))))
-
 (import (sx text-layout))

shared/static/wasm/sx/hs-compiler.sx

@@ -240,18 +240,22 @@
           ((prop (nth ast 1)) (value (hs-to-sx (nth ast 2))))
           (if
             (= (len ast) 5)
+            (let
+              ((raw-tgt (nth ast 4)))
               (list
                 (quote hs-transition)
-              (hs-to-sx (nth ast 4))
+                (if (nil? raw-tgt) (quote me) (hs-to-sx raw-tgt))
                 prop
                 value
-              (nth ast 3))
+                (nth ast 3)))
+            (let
+              ((raw-tgt (nth ast 3)))
               (list
                 (quote hs-transition)
-              (hs-to-sx (nth ast 3))
+                (if (nil? raw-tgt) (quote me) (hs-to-sx raw-tgt))
                 prop
                 value
-              nil)))))
+                nil))))))
     (define
       emit-make
       (fn
@@ -913,6 +917,19 @@
                       (list (quote dom-set-style) tgt "visibility" "visible"))
                     (true (list (quote dom-set-style) tgt "display" "")))))
               ((= head (quote transition)) (emit-transition ast))
+              ((= head (quote transition-from))
+                (let
+                  ((prop (nth ast 1))
+                    (from-val (hs-to-sx (nth ast 2)))
+                    (to-val (hs-to-sx (nth ast 3)))
+                    (dur (nth ast 4)))
+                  (list
+                    (quote hs-transition-from)
+                    (quote me)
+                    prop
+                    from-val
+                    to-val
+                    dur)))
               ((= head (quote repeat)) (emit-repeat ast))
               ((= head (quote fetch))
                 (list (quote hs-fetch) (hs-to-sx (nth ast 1)) (nth ast 2)))

shared/static/wasm/sx/hs-parser.sx

@@ -1011,18 +1011,21 @@
         (fn
           ()
           (let
-            ((prop (cond ((= (tp-type) "style") (get (adv!) "value")) ((and (= (tp-val) "my") (= (get (nth tokens (+ p 1)) "type") "style")) (do (adv!) (get (adv!) "value"))) (true (get (adv!) "value")))))
+            ((prop (cond ((= (tp-type) "style") (get (adv!) "value")) ((= (tp-val) "my") (do (adv!) (if (= (tp-type) "style") (get (adv!) "value") (get (adv!) "value")))) (true (get (adv!) "value")))))
+            (let
+              ((from-val (if (match-kw "from") (parse-expr) nil)))
               (expect-kw! "to")
               (let
                 ((value (parse-expr)))
                 (let
                   ((dur (if (match-kw "over") (parse-expr) nil)))
-                (let
-                  ((tgt nil))
+                  (if
+                    from-val
+                    (list (quote transition-from) prop from-val value dur)
                     (if
                       dur
-                    (list (quote transition) prop value dur tgt)
-                    (list (quote transition) prop value tgt))))))))
+                      (list (quote transition) prop value dur nil)
+                      (list (quote transition) prop value nil)))))))))
       (define
         parse-repeat-cmd
         (fn

shared/static/wasm/sx/hs-runtime.sx

@@ -344,6 +344,20 @@
     (dom-set-style target prop value)
     (when duration (hs-settle target))))
 
+(define
+  hs-transition-from
+  (fn
+    (target prop from-val to-val duration)
+    (dom-set-style target prop (str from-val))
+    (when
+      duration
+      (dom-set-style
+        target
+        "transition"
+        (str prop " " (/ duration 1000) "s")))
+    (dom-set-style target prop (str to-val))
+    (when duration (hs-settle target))))
+
 (define
   hs-type-check
   (fn
@@ -359,20 +373,21 @@
         ((= type-name "Object") (dict? value))
         (true true)))))
 
+
+
+
+
 (define
   hs-type-check-strict
   (fn
     (value type-name)
     (if (nil? value) false (hs-type-check value type-name))))
 
-
-
-
-
 (define
   hs-strict-eq
   (fn (a b) (and (= (type-of a) (type-of b)) (= a b))))
-
+;; ── Sandbox/test runtime additions ──────────────────────────────
+;; Property access — dot notation and .length
 (define
   hs-falsy?
   (fn
@@ -384,8 +399,7 @@
       ((and (list? v) (= (len v) 0)) true)
       ((= v 0) true)
       (true false))))
-;; ── Sandbox/test runtime additions ──────────────────────────────
-;; Property access — dot notation and .length
+;; DOM query stub — sandbox returns empty list
 (define
   hs-matches?
   (fn
@@ -394,7 +408,7 @@
       (string? target)
       (if (= pattern ".*") true (string-contains? target pattern))
       false)))
-;; DOM query stub — sandbox returns empty list
+;; Method dispatch — obj.method(args)
 (define
   hs-contains?
   (fn
@@ -414,11 +428,11 @@
               true
               (hs-contains? (rest collection) item)))))
       (true false))))
-;; Method dispatch — obj.method(args)
-(define precedes? (fn (a b) (< (str a) (str b))))
 
 ;; ── 0.9.90 features ─────────────────────────────────────────────
 ;; beep! — debug logging, returns value unchanged
+(define precedes? (fn (a b) (< (str a) (str b))))
+;; Property-based is — check obj.key truthiness
 (define
   hs-empty?
   (fn
@@ -429,11 +443,11 @@
       ((list? v) (= (len v) 0))
       ((dict? v) (= (len (keys v)) 0))
       (true false))))
-;; Property-based is — check obj.key truthiness
-(define hs-first (fn (lst) (first lst)))
 ;; Array slicing (inclusive both ends)
-(define hs-last (fn (lst) (last lst)))
+(define hs-first (fn (lst) (first lst)))
 ;; Collection: sorted by
+(define hs-last (fn (lst) (last lst)))
+;; Collection: sorted by descending
 (define
   hs-template
   (fn
@@ -519,7 +533,7 @@
                   (set! i (+ i 1))
                   (tpl-loop)))))))
       (do (tpl-loop) result))))
-;; Collection: sorted by descending
+;; Collection: split by
 (define
   hs-make-object
   (fn
@@ -531,7 +545,7 @@
           (fn (pair) (dict-set! d (first pair) (nth pair 1)))
           pairs)
         d))))
-;; Collection: split by
+;; Collection: joined by
 (define
   hs-method-call
   (fn
@@ -554,7 +568,7 @@
                 (if (= (first lst) item) i (idx-loop (rest lst) (+ i 1))))))
           (idx-loop obj 0)))
       (true nil))))
-;; Collection: joined by
+
 (define hs-beep (fn (v) v))
 
 (define hs-prop-is (fn (obj key) (not (hs-falsy? (host-get obj key)))))

shared/static/wasm/sx/module-manifest.json

@@ -1011,6 +1011,7 @@
       "hs-install",
       "hs-measure",
       "hs-transition",
+      "hs-transition-from",
       "hs-type-check",
       "hs-type-check-strict",
       "hs-strict-eq",

shared/static/wasm/sx/text-layout.sx

@@ -13,21 +13,6 @@
 ;; Knuth-Plass optimal line breaking (DP over break candidates).
 ;; Liang's hyphenation (trie over character patterns).
 
-(define
-  pretext-position-line
-  (fn
-    (words widths gap-w)
-    (let
-      loop
-      ((i 0) (x 0) (acc (list)))
-      (if
-        (>= i (len words))
-        acc
-        (loop
-          (+ i 1)
-          (+ x (nth widths i) gap-w)
-          (append acc (list {:width (nth widths i) :x x :word (nth words i)})))))))
-
 (define-library
   (sx text-layout)
   (export
@@ -149,6 +134,32 @@
               (let
                 ((ends (append (rest starts) (list n))))
                 (map-indexed (fn (i s) (list s (nth ends i))) starts)))))))
+    (define
+      break-lines-greedy
+      (fn
+        (widths space-width max-width)
+        (let
+          ((n (len widths)))
+          (if
+            (= n 0)
+            (list)
+            (let
+              ((lines (list)) (start 0) (used 0))
+              (for-each
+                (fn
+                  (i)
+                  (let
+                    ((w (nth widths i))
+                      (needed (if (= i start) w (+ used space-width w))))
+                    (if
+                      (and (> needed max-width) (not (= i start)))
+                      (do
+                        (set! lines (append lines (list (list start i))))
+                        (set! start i)
+                        (set! used w))
+                      (set! used needed))))
+                (range n))
+              (append lines (list (list start n))))))))
     (define
       position-line
       (fn
@@ -181,6 +192,45 @@
                   (line-widths (slice widths start end)))
                 (position-line line-words line-widths space-width x0 y))))
           line-ranges)))
+    (define
+      pretext-position-line
+      (fn
+        (words widths gap-w)
+        (let
+          loop
+          ((i 0) (x 0) (acc (list)))
+          (if
+            (>= i (len words))
+            acc
+            (loop
+              (+ i 1)
+              (+ x (nth widths i) gap-w)
+              (append acc (list {:width (nth widths i) :x x :word (nth words i)})))))))
+    (define
+      pretext-layout-lines
+      (fn
+        (words widths ranges space-width max-width line-height)
+        (let
+          ((n-lines (len ranges)))
+          (map
+            (fn
+              (line-idx)
+              (let
+                ((range (nth ranges line-idx))
+                  (y (* line-idx line-height)))
+                (let
+                  ((start (first range)) (end (nth range 1)))
+                  (let
+                    ((lw (slice words start end))
+                      (lwid (slice widths start end)))
+                    (let
+                      ((total-w (reduce + 0 lwid))
+                        (n-gaps (max 1 (- (len lw) 1)))
+                        (is-last (= line-idx (- n-lines 1))))
+                      (let
+                        ((gap (if is-last space-width (/ (- max-width total-w) n-gaps))))
+                        {:y y :words (pretext-position-line lw lwid gap)}))))))
+            (range n-lines)))))
     (define
       make-hyphenation-trie
       (fn
@@ -327,31 +377,4 @@
             (lh (or line-height 1.4)))
           (layout-paragraph words f s w lh))))))
 
-(define
-  break-lines-greedy
-  (fn
-    (widths space-width max-width)
-    (let
-      ((n (len widths)))
-      (if
-        (= n 0)
-        (list)
-        (let
-          ((lines (list)) (start 0) (used 0))
-          (for-each
-            (fn
-              (i)
-              (let
-                ((w (nth widths i))
-                  (needed (if (= i start) w (+ used space-width w))))
-                (if
-                  (and (> needed max-width) (not (= i start)))
-                  (do
-                    (set! lines (append lines (list (list start i))))
-                    (set! start i)
-                    (set! used w))
-                  (set! used needed))))
-            (range n))
-          (append lines (list (list start n))))))))
-
 (import (sx text-layout))

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-80a20737",[2,3]],["jsoo_runtime-f96b44a8",[2]],["js_of_ocaml-651f6707",[2,5]],["dune__exe__Sx_browser-08c26bf2",[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-80a20737",[2,3]],["jsoo_runtime-f96b44a8",[2]],["js_of_ocaml-651f6707",[2,5]],["dune__exe__Sx_browser-653fa705",[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

sx/sx/pretext-client.sx

@@ -1,4 +1,5 @@
 ;; Pretext island — client-side text layout with live controls
+;; Uses bytecode-compiled break-lines from text-layout library.
 
 (defisland
   ~pretext-demo/live
@@ -13,51 +14,9 @@
       (canvas (host-call doc "createElement" "canvas"))
       (ctx (host-call canvas "getContext" "2d")))
     (let
-      ((mw (fn (word sz) (do (host-set! ctx "font" (str sz "px 'Pretext Serif', DejaVu Serif, serif")) (host-get (host-call ctx "measureText" word) "width"))))
-        (sw-fn
-          (fn
-            (widths sw from to)
+      ((mw (fn (word sz) (do (host-set! ctx "font" (str sz "px 'Pretext Serif', DejaVu Serif, serif")) (host-get (host-call ctx "measureText" word) "width")))))
       (let
-              loop
-              ((k from) (total 0))
-              (if
-                (>= k to)
-                (+ total (* (max 0 (- (- to from) 1)) sw))
-                (loop (+ k 1) (+ total (nth widths k)))))))
-        (brk-greedy
-          (fn
-            (widths sw mx)
-            (let
-              ((n (len widths)) (lines (list)) (st 0) (us 0))
-              (for-each
-                (fn
-                  (i)
-                  (let
-                    ((w (nth widths i)) (nd (if (= i st) w (+ us sw w))))
-                    (if
-                      (and (> nd mx) (not (= i st)))
-                      (do
-                        (set! lines (append lines (list (list st i))))
-                        (set! st i)
-                        (set! us w))
-                      (set! us nd))))
-                (range n))
-              (append lines (list (list st n))))))
-        (pos-line
-          (fn
-            (lw lwid gap)
-            (let
-              loop
-              ((i 0) (x 0) (acc (list)))
-              (if
-                (>= i (len lw))
-                acc
-                (loop
-                  (+ i 1)
-                  (+ x (nth lwid i) gap)
-                  (append acc (list {:x x :word (nth lw i)}))))))))
-      (let
-        ((layout (computed (fn () (let ((sz (deref font-size)) (mxw (deref max-w)) (opt (deref use-optimal))) (let ((widths (map (fn (w) (mw w sz)) words)) (spw (mw " " sz)) (lh (* sz 1.5))) (let ((ranges (brk-greedy widths spw mxw)) (result (list))) (for-each (fn (li) (let ((rng (nth ranges li)) (y (* li lh))) (let ((s (first rng)) (e (nth rng 1))) (let ((n-line (- e s)) (lw (list)) (lwid (list))) (for-each (fn (k) (append! lw (nth words (+ s k))) (append! lwid (nth widths (+ s k)))) (range n-line)) (let ((tw (reduce + 0 lwid)) (ng (max 1 (- n-line 1))) (il (= li (- (len ranges) 1)))) (let ((gap (if il spw (/ (- mxw tw) ng)))) (append! result {:y y :words (pos-line lw lwid gap)}))))))) (range (len ranges))) result)))))))
+        ((layout (computed (fn () (let ((sz (deref font-size)) (mxw (deref max-w)) (opt (deref use-optimal))) (let ((widths (map (fn (w) (mw w sz)) words)) (spw (mw " " sz)) (lh (* sz 1.5))) (let ((ranges (if opt (break-lines widths spw mxw) (break-lines-greedy widths spw mxw)))) (pretext-layout-lines words widths ranges spw mxw lh))))))))
         (div
           (~tw :tokens "space-y-4")
           (div