Unify scoped effects: scope as general primitive, provide as sugar

- Add `scope` special form to eval.sx: (scope name body...) or
  (scope name :value v body...) — general dynamic scope primitive
- `provide` becomes sugar: (provide name value body...) calls scope
- Rename provide-push!/provide-pop! to scope-push!/scope-pop! throughout
  all adapters (async, dom, html, sx) and platform implementations
- Update boundary.sx: Tier 5 now "Scoped effects" with scope-push!/
  scope-pop! as primary, provide-push!/provide-pop! as aliases
- Add scope form handling to async adapter and aser wire format
- Update sx-browser.js, sx_ref.py (bootstrapped output)
- Add scopes.sx docs page, update provide/spreads/demo docs
- Update nav-data, page-functions, docs page definitions

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

shared/sx/ref/adapter-async.sx

@@ -175,14 +175,14 @@
                        (svg-context-set! true)
                        nil))
               (content-parts (list)))
-          (provide-push! "element-attrs" nil)
+          (scope-push! "element-attrs" nil)
           (for-each
             (fn (c) (append! content-parts (async-render c env ctx)))
             children)
           (for-each
             (fn (spread-dict) (merge-spread-attrs attrs spread-dict))
             (emitted "element-attrs"))
-          (provide-pop! "element-attrs")
+          (scope-pop! "element-attrs")
           (when token (svg-context-reset! token))
           (str "<" tag (render-attrs attrs) ">"
             (join "" content-parts)
@@ -335,7 +335,7 @@
   (list "if" "when" "cond" "case" "let" "let*" "begin" "do"
         "define" "defcomp" "defisland" "defmacro" "defstyle" "defhandler"
         "deftype" "defeffect"
-        "map" "map-indexed" "filter" "for-each" "provide"))
+        "map" "map-indexed" "filter" "for-each" "scope" "provide"))
 
 (define async-render-form? :effects []
   (fn ((name :as string))
@@ -419,17 +419,37 @@
               (coll (async-eval (nth expr 2) env ctx)))
           (join "" (async-map-fn-render f coll env ctx)))
 
-      ;; provide — render-time dynamic scope
+      ;; scope — unified render-time dynamic scope
+      (= name "scope")
+        (let ((scope-name (async-eval (nth expr 1) env ctx))
+              (rest-args (slice expr 2))
+              (scope-val nil)
+              (body-exprs nil))
+          ;; Check for :value keyword
+          (if (and (>= (len rest-args) 2)
+                   (= (type-of (first rest-args)) "keyword")
+                   (= (keyword-name (first rest-args)) "value"))
+            (do (set! scope-val (async-eval (nth rest-args 1) env ctx))
+                (set! body-exprs (slice rest-args 2)))
+            (set! body-exprs rest-args))
+          (scope-push! scope-name scope-val)
+          (let ((result (if (= (len body-exprs) 1)
+                          (async-render (first body-exprs) env ctx)
+                          (join "" (async-map-render body-exprs env ctx)))))
+            (scope-pop! scope-name)
+            result))
+
+      ;; provide — sugar for scope with value
       (= name "provide")
         (let ((prov-name (async-eval (nth expr 1) env ctx))
               (prov-val (async-eval (nth expr 2) env ctx))
               (body-start 3)
               (body-count (- (len expr) 3)))
-          (provide-push! prov-name prov-val)
+          (scope-push! prov-name prov-val)
           (let ((result (if (= body-count 1)
                           (async-render (nth expr body-start) env ctx)
                           (join "" (async-map-render (slice expr body-start) env ctx)))))
-            (provide-pop! prov-name)
+            (scope-pop! prov-name)
             result))
 
       ;; Fallback
@@ -847,7 +867,7 @@
           (skip false)
           (i 0))
       ;; Provide scope for spread emit!
-      (provide-push! "element-attrs" nil)
+      (scope-push! "element-attrs" nil)
       (for-each
         (fn (arg)
           (if skip
@@ -890,7 +910,7 @@
                 (append! attr-parts (serialize v))))
             (keys spread-dict)))
         (emitted "element-attrs"))
-      (provide-pop! "element-attrs")
+      (scope-pop! "element-attrs")
       (when token (svg-context-reset! token))
       (let ((parts (concat (list name) attr-parts child-parts)))
         (make-sx-expr (str "(" (join " " parts) ")"))))))
@@ -906,7 +926,7 @@
         "define" "defcomp" "defmacro" "defstyle"
         "defhandler" "defpage" "defquery" "defaction"
         "begin" "do" "quote" "->" "set!" "defisland"
-        "deftype" "defeffect" "provide"))
+        "deftype" "defeffect" "scope" "provide"))
 
 (define ASYNC_ASER_HO_NAMES
   (list "map" "map-indexed" "filter" "for-each"))
@@ -1044,15 +1064,35 @@
             (= name "deftype") (= name "defeffect"))
           (do (async-eval expr env ctx) nil)
 
-        ;; provide — render-time dynamic scope
+        ;; scope — unified render-time dynamic scope
+        (= name "scope")
+          (let ((scope-name (async-eval (first args) env ctx))
+                (rest-args (rest args))
+                (scope-val nil)
+                (body-args nil))
+            ;; Check for :value keyword
+            (if (and (>= (len rest-args) 2)
+                     (= (type-of (first rest-args)) "keyword")
+                     (= (keyword-name (first rest-args)) "value"))
+              (do (set! scope-val (async-eval (nth rest-args 1) env ctx))
+                  (set! body-args (slice rest-args 2)))
+              (set! body-args rest-args))
+            (scope-push! scope-name scope-val)
+            (let ((result nil))
+              (for-each (fn (body) (set! result (async-aser body env ctx)))
+                        body-args)
+              (scope-pop! scope-name)
+              result))
+
+        ;; provide — sugar for scope with value
         (= name "provide")
           (let ((prov-name (async-eval (first args) env ctx))
                 (prov-val (async-eval (nth args 1) env ctx))
                 (result nil))
-            (provide-push! prov-name prov-val)
+            (scope-push! prov-name prov-val)
             (for-each (fn (body) (set! result (async-aser body env ctx)))
                       (slice args 2))
-            (provide-pop! prov-name)
+            (scope-pop! prov-name)
             result)
 
         ;; Fallback

shared/sx/ref/adapter-dom.sx

@@ -181,7 +181,7 @@
           (el (dom-create-element tag new-ns)))
 
       ;; Provide scope for spread emit! — deeply nested spreads emit here
-      (provide-push! "element-attrs" nil)
+      (scope-push! "element-attrs" nil)
 
       ;; Process args: keywords → attrs, others → children
       (reduce
@@ -269,7 +269,7 @@
                     (dom-set-attr el key (str val))))))
             (keys spread-dict)))
         (emitted "element-attrs"))
-      (provide-pop! "element-attrs")
+      (scope-pop! "element-attrs")
 
       el)))
 
@@ -381,7 +381,7 @@
   (list "if" "when" "cond" "case" "let" "let*" "begin" "do"
         "define" "defcomp" "defisland" "defmacro" "defstyle" "defhandler"
         "map" "map-indexed" "filter" "for-each" "portal"
-        "error-boundary" "provide"))
+        "error-boundary" "scope" "provide"))
 
 (define render-dom-form? :effects []
   (fn ((name :as string))
@@ -637,17 +637,39 @@
             coll)
           frag)
 
-      ;; provide — render-time dynamic scope
+      ;; scope — unified render-time dynamic scope
+      (= name "scope")
+        (let ((scope-name (trampoline (eval-expr (nth expr 1) env)))
+              (rest-args (slice expr 2))
+              (scope-val nil)
+              (body-exprs nil)
+              (frag (create-fragment)))
+          ;; Check for :value keyword
+          (if (and (>= (len rest-args) 2)
+                   (= (type-of (first rest-args)) "keyword")
+                   (= (keyword-name (first rest-args)) "value"))
+            (do (set! scope-val (trampoline (eval-expr (nth rest-args 1) env)))
+                (set! body-exprs (slice rest-args 2)))
+            (set! body-exprs rest-args))
+          (scope-push! scope-name scope-val)
+          (for-each
+            (fn (e)
+              (dom-append frag (render-to-dom e env ns)))
+            body-exprs)
+          (scope-pop! scope-name)
+          frag)
+
+      ;; provide — sugar for scope with value
       (= name "provide")
         (let ((prov-name (trampoline (eval-expr (nth expr 1) env)))
               (prov-val (trampoline (eval-expr (nth expr 2) env)))
               (frag (create-fragment)))
-          (provide-push! prov-name prov-val)
+          (scope-push! prov-name prov-val)
           (for-each
             (fn (i)
               (dom-append frag (render-to-dom (nth expr i) env ns)))
             (range 3 (len expr)))
-          (provide-pop! prov-name)
+          (scope-pop! prov-name)
           frag)
 
       ;; Fallback

shared/sx/ref/adapter-html.sx

@@ -56,7 +56,7 @@
   (list "if" "when" "cond" "case" "let" "let*" "begin" "do"
         "define" "defcomp" "defisland" "defmacro" "defstyle" "defhandler"
         "deftype" "defeffect"
-        "map" "map-indexed" "filter" "for-each" "provide"))
+        "map" "map-indexed" "filter" "for-each" "scope" "provide"))
 
 (define render-html-form? :effects []
   (fn ((name :as string))
@@ -229,18 +229,38 @@
                   (render-to-html (apply f (list item)) env)))
               coll)))
 
-      ;; provide — render-time dynamic scope
+      ;; scope — unified render-time dynamic scope
+      (= name "scope")
+        (let ((scope-name (trampoline (eval-expr (nth expr 1) env)))
+              (rest-args (slice expr 2))
+              (scope-val nil)
+              (body-exprs nil))
+          ;; Check for :value keyword
+          (if (and (>= (len rest-args) 2)
+                   (= (type-of (first rest-args)) "keyword")
+                   (= (keyword-name (first rest-args)) "value"))
+            (do (set! scope-val (trampoline (eval-expr (nth rest-args 1) env)))
+                (set! body-exprs (slice rest-args 2)))
+            (set! body-exprs rest-args))
+          (scope-push! scope-name scope-val)
+          (let ((result (if (= (len body-exprs) 1)
+                          (render-to-html (first body-exprs) env)
+                          (join "" (map (fn (e) (render-to-html e env)) body-exprs)))))
+            (scope-pop! scope-name)
+            result))
+
+      ;; provide — sugar for scope with value
       (= name "provide")
         (let ((prov-name (trampoline (eval-expr (nth expr 1) env)))
               (prov-val (trampoline (eval-expr (nth expr 2) env)))
               (body-start 3)
               (body-count (- (len expr) 3)))
-          (provide-push! prov-name prov-val)
+          (scope-push! prov-name prov-val)
           (let ((result (if (= body-count 1)
                           (render-to-html (nth expr body-start) env)
                           (join "" (map (fn (i) (render-to-html (nth expr i) env))
                                        (range body-start (+ body-start body-count)))))))
-            (provide-pop! prov-name)
+            (scope-pop! prov-name)
             result))
 
       ;; Fallback
@@ -314,12 +334,12 @@
         (str "<" tag (render-attrs attrs) " />")
         ;; Provide scope for spread emit!
         (do
-          (provide-push! "element-attrs" nil)
+          (scope-push! "element-attrs" nil)
           (let ((content (join "" (map (fn (c) (render-to-html c env)) children))))
             (for-each
               (fn (spread-dict) (merge-spread-attrs attrs spread-dict))
               (emitted "element-attrs"))
-            (provide-pop! "element-attrs")
+            (scope-pop! "element-attrs")
             (str "<" tag (render-attrs attrs) ">"
               content
               "</" tag ">")))))))
@@ -359,12 +379,12 @@
         args)
       ;; Provide scope for spread emit!
       (let ((lake-attrs (dict "data-sx-lake" (or lake-id ""))))
-        (provide-push! "element-attrs" nil)
+        (scope-push! "element-attrs" nil)
         (let ((content (join "" (map (fn (c) (render-to-html c env)) children))))
           (for-each
             (fn (spread-dict) (merge-spread-attrs lake-attrs spread-dict))
             (emitted "element-attrs"))
-          (provide-pop! "element-attrs")
+          (scope-pop! "element-attrs")
           (str "<" lake-tag (render-attrs lake-attrs) ">"
                content
                "</" lake-tag ">"))))))
@@ -407,12 +427,12 @@
         args)
       ;; Provide scope for spread emit!
       (let ((marsh-attrs (dict "data-sx-marsh" (or marsh-id ""))))
-        (provide-push! "element-attrs" nil)
+        (scope-push! "element-attrs" nil)
         (let ((content (join "" (map (fn (c) (render-to-html c env)) children))))
           (for-each
             (fn (spread-dict) (merge-spread-attrs marsh-attrs spread-dict))
             (emitted "element-attrs"))
-          (provide-pop! "element-attrs")
+          (scope-pop! "element-attrs")
           (str "<" marsh-tag (render-attrs marsh-attrs) ">"
                content
                "</" marsh-tag ">"))))))

shared/sx/ref/adapter-sx.sx

@@ -144,7 +144,7 @@
           (skip false)
           (i 0))
       ;; Provide scope for spread emit!
-      (provide-push! "element-attrs" nil)
+      (scope-push! "element-attrs" nil)
       (for-each
         (fn (arg)
           (if skip
@@ -179,7 +179,7 @@
                 (append! attr-parts (serialize v))))
             (keys spread-dict)))
         (emitted "element-attrs"))
-      (provide-pop! "element-attrs")
+      (scope-pop! "element-attrs")
       (let ((parts (concat (list name) attr-parts child-parts)))
         (str "(" (join " " parts) ")")))))
 
@@ -195,7 +195,7 @@
         "defhandler" "defpage" "defquery" "defaction" "defrelation"
         "begin" "do" "quote" "quasiquote"
         "->" "set!" "letrec" "dynamic-wind" "defisland"
-        "deftype" "defeffect" "provide"))
+        "deftype" "defeffect" "scope" "provide"))
 
 (define HO_FORM_NAMES
   (list "map" "map-indexed" "filter" "reduce"
@@ -333,15 +333,35 @@
             (= name "deftype") (= name "defeffect"))
           (do (trampoline (eval-expr expr env)) nil)
 
-        ;; provide — render-time dynamic scope
+        ;; scope — unified render-time dynamic scope
+        (= name "scope")
+          (let ((scope-name (trampoline (eval-expr (first args) env)))
+                (rest-args (rest args))
+                (scope-val nil)
+                (body-args nil))
+            ;; Check for :value keyword
+            (if (and (>= (len rest-args) 2)
+                     (= (type-of (first rest-args)) "keyword")
+                     (= (keyword-name (first rest-args)) "value"))
+              (do (set! scope-val (trampoline (eval-expr (nth rest-args 1) env)))
+                  (set! body-args (slice rest-args 2)))
+              (set! body-args rest-args))
+            (scope-push! scope-name scope-val)
+            (let ((result nil))
+              (for-each (fn (body) (set! result (aser body env)))
+                        body-args)
+              (scope-pop! scope-name)
+              result))
+
+        ;; provide — sugar for scope with value
         (= name "provide")
           (let ((prov-name (trampoline (eval-expr (first args) env)))
                 (prov-val (trampoline (eval-expr (nth args 1) env)))
                 (result nil))
-            (provide-push! prov-name prov-val)
+            (scope-push! prov-name prov-val)
             (for-each (fn (body) (set! result (aser body env)))
                       (slice args 2))
-            (provide-pop! prov-name)
+            (scope-pop! prov-name)
             result)
 
         ;; Everything else — evaluate normally

shared/sx/ref/bootstrap_py.py

@@ -293,6 +293,8 @@ class PyEmitter:
             "collect!": "sx_collect",
             "collected": "sx_collected",
             "clear-collected!": "sx_clear_collected",
+            "scope-push!": "scope_push",
+            "scope-pop!": "scope_pop",
             "provide-push!": "provide_push",
             "provide-pop!": "provide_pop",
             "context": "sx_context",

shared/sx/ref/boundary.sx

@@ -374,30 +374,44 @@
 
 
 ;; --------------------------------------------------------------------------
-;; Tier 5: Dynamic scope — render-time provide/context/emit!
+;; Tier 5: Scoped effects — unified render-time dynamic scope
 ;;
-;; `provide` is a special form (not a primitive) that creates a named scope
-;; with a value and an empty accumulator. `context` reads the value from the
-;; nearest enclosing provider. `emit!` appends to the accumulator, `emitted`
-;; reads the accumulated values.
+;; `scope` is the general primitive. `provide` is sugar for scope-with-value.
+;; Both `provide` and `scope` are special forms in the evaluator.
 ;;
-;; The platform must implement per-name stacks. Each entry has a value and
-;; an emitted list. `provide-push!`/`provide-pop!` manage the stack.
+;; The platform must implement per-name stacks. Each entry has a value,
+;; an emitted list, and a dedup flag. `scope-push!`/`scope-pop!` manage
+;; the stack. `provide-push!`/`provide-pop!` are aliases.
+;;
+;; `collect!`/`collected`/`clear-collected!` (Tier 4) are backed by scopes:
+;; collect! lazily creates a root scope with dedup=true, then emits into it.
 ;; --------------------------------------------------------------------------
 
-(declare-tier :dynamic-scope :source "eval.sx")
+(declare-tier :scoped-effects :source "eval.sx")
+
+(declare-spread-primitive "scope-push!"
+  :params (name value)
+  :returns "nil"
+  :effects [mutation]
+  :doc "Push a scope with name and value. General form — provide-push! is an alias.")
+
+(declare-spread-primitive "scope-pop!"
+  :params (name)
+  :returns "nil"
+  :effects [mutation]
+  :doc "Pop the most recent scope for name. General form — provide-pop! is an alias.")
 
 (declare-spread-primitive "provide-push!"
   :params (name value)
   :returns "nil"
   :effects [mutation]
-  :doc "Push a provider scope with name and value (platform internal).")
+  :doc "Alias for scope-push!. Push a scope with name and value.")
 
 (declare-spread-primitive "provide-pop!"
   :params (name)
   :returns "nil"
   :effects [mutation]
-  :doc "Pop the most recent provider scope for name (platform internal).")
+  :doc "Alias for scope-pop!. Pop the most recent scope for name.")
 
 (declare-spread-primitive "context"
   :params (name &rest default)

shared/sx/ref/eval.sx

@@ -162,6 +162,7 @@
               (= name "reset")       (sf-reset args env)
               (= name "shift")       (sf-shift args env)
               (= name "dynamic-wind") (sf-dynamic-wind args env)
+              (= name "scope")      (sf-scope args env)
               (= name "provide")    (sf-provide args env)
 
               ;; Higher-order forms
@@ -951,11 +952,35 @@
 
 
 ;; --------------------------------------------------------------------------
-;; 6a2. provide — render-time dynamic scope
+;; 6a2. scope — unified render-time dynamic scope primitive
 ;; --------------------------------------------------------------------------
 ;;
-;; (provide name value body...) — push a named scope with value and empty
-;; accumulator, evaluate body, pop scope. Returns last body result.
+;; (scope name body...) or (scope name :value v body...)
+;; Push a named scope with optional value and empty accumulator,
+;; evaluate body, pop scope. Returns last body result.
+;;
+;; `provide` is sugar: (provide name value body...) = (scope name :value value body...)
+
+(define sf-scope
+  (fn ((args :as list) (env :as dict))
+    (let ((name (trampoline (eval-expr (first args) env)))
+          (rest (slice args 1))
+          (val nil)
+          (body-exprs nil))
+      ;; Check for :value keyword
+      (if (and (>= (len rest) 2) (= (type-of (first rest)) "keyword") (= (keyword-name (first rest)) "value"))
+        (do (set! val (trampoline (eval-expr (nth rest 1) env)))
+            (set! body-exprs (slice rest 2)))
+        (set! body-exprs rest))
+      (scope-push! name val)
+      (let ((result nil))
+        (for-each (fn (e) (set! result (trampoline (eval-expr e env)))) body-exprs)
+        (scope-pop! name)
+        result))))
+
+
+;; provide — sugar for scope with a value
+;; (provide name value body...) → (scope name :value value body...)
 
 (define sf-provide
   (fn ((args :as list) (env :as dict))
@@ -963,9 +988,9 @@
           (val (trampoline (eval-expr (nth args 1) env)))
           (body-exprs (slice args 2))
           (result nil))
-      (provide-push! name val)
+      (scope-push! name val)
       (for-each (fn (e) (set! result (trampoline (eval-expr e env)))) body-exprs)
-      (provide-pop! name)
+      (scope-pop! name)
       result)))
 
 

shared/sx/ref/js.sx

@@ -527,6 +527,8 @@
   "collect!" "sxCollect"
   "collected" "sxCollected"
   "clear-collected!" "sxClearCollected"
+  "scope-push!" "scopePush"
+  "scope-pop!" "scopePop"
   "provide-push!" "providePush"
   "provide-pop!" "providePop"
   "context" "sxContext"

shared/sx/ref/platform_js.py

@@ -883,8 +883,7 @@ PREAMBLE = '''\
   function SxSpread(attrs) { this.attrs = attrs || {}; }
   SxSpread.prototype._spread = true;
 
-  var _collectBuckets = {};
-  var _provideStacks = {};
+  var _scopeStacks = {};
 
   function isSym(x) { return x != null && x._sym === true; }
   function isKw(x) { return x != null && x._kw === true; }
@@ -1098,14 +1097,17 @@ PRIMITIVES_JS_MODULES: dict[str, str] = {
 ''',
 
     "stdlib.spread": '''
-  // stdlib.spread — spread + collect primitives
+  // stdlib.spread — spread + collect + scope primitives
   PRIMITIVES["make-spread"] = makeSpread;
   PRIMITIVES["spread?"] = isSpread;
   PRIMITIVES["spread-attrs"] = spreadAttrs;
   PRIMITIVES["collect!"] = sxCollect;
   PRIMITIVES["collected"] = sxCollected;
   PRIMITIVES["clear-collected!"] = sxClearCollected;
-  // provide/context/emit! — render-time dynamic scope
+  // scope — unified render-time dynamic scope
+  PRIMITIVES["scope-push!"] = scopePush;
+  PRIMITIVES["scope-pop!"] = scopePop;
+  // provide-push!/provide-pop! — aliases for scope-push!/scope-pop!
   PRIMITIVES["provide-push!"] = providePush;
   PRIMITIVES["provide-pop!"] = providePop;
   PRIMITIVES["context"] = sxContext;
@@ -1174,44 +1176,54 @@ PLATFORM_JS_PRE = '''
   function isSpread(x) { return x != null && x._spread === true; }
   function spreadAttrs(s) { return s && s._spread ? s.attrs : {}; }
 
-  function sxCollect(bucket, value) {
-    if (!_collectBuckets[bucket]) _collectBuckets[bucket] = [];
-    var items = _collectBuckets[bucket];
-    if (items.indexOf(value) === -1) items.push(value);
+  function scopePush(name, value) {
+    if (!_scopeStacks[name]) _scopeStacks[name] = [];
+    _scopeStacks[name].push({value: value !== undefined ? value : NIL, emitted: [], dedup: false});
   }
-  function sxCollected(bucket) {
-    return _collectBuckets[bucket] ? _collectBuckets[bucket].slice() : [];
-  }
-  function sxClearCollected(bucket) {
-    if (_collectBuckets[bucket]) _collectBuckets[bucket] = [];
+  function scopePop(name) {
+    if (_scopeStacks[name] && _scopeStacks[name].length) _scopeStacks[name].pop();
   }
+  // Aliases — provide-push!/provide-pop! map to scope-push!/scope-pop!
+  var providePush = scopePush;
+  var providePop = scopePop;
 
-  function providePush(name, value) {
-    if (!_provideStacks[name]) _provideStacks[name] = [];
-    _provideStacks[name].push({value: value !== undefined ? value : NIL, emitted: []});
-  }
-  function providePop(name) {
-    if (_provideStacks[name] && _provideStacks[name].length) _provideStacks[name].pop();
-  }
   function sxContext(name) {
-    if (_provideStacks[name] && _provideStacks[name].length) {
-      return _provideStacks[name][_provideStacks[name].length - 1].value;
+    if (_scopeStacks[name] && _scopeStacks[name].length) {
+      return _scopeStacks[name][_scopeStacks[name].length - 1].value;
     }
     if (arguments.length > 1) return arguments[1];
     throw new Error("No provider for: " + name);
   }
   function sxEmit(name, value) {
-    if (_provideStacks[name] && _provideStacks[name].length) {
-      _provideStacks[name][_provideStacks[name].length - 1].emitted.push(value);
+    if (_scopeStacks[name] && _scopeStacks[name].length) {
+      var entry = _scopeStacks[name][_scopeStacks[name].length - 1];
+      if (entry.dedup && entry.emitted.indexOf(value) !== -1) return NIL;
+      entry.emitted.push(value);
     }
     return NIL;
   }
   function sxEmitted(name) {
-    if (_provideStacks[name] && _provideStacks[name].length) {
-      return _provideStacks[name][_provideStacks[name].length - 1].emitted.slice();
+    if (_scopeStacks[name] && _scopeStacks[name].length) {
+      return _scopeStacks[name][_scopeStacks[name].length - 1].emitted.slice();
     }
     return [];
   }
+  function sxCollect(bucket, value) {
+    if (!_scopeStacks[bucket] || !_scopeStacks[bucket].length) {
+      if (!_scopeStacks[bucket]) _scopeStacks[bucket] = [];
+      _scopeStacks[bucket].push({value: NIL, emitted: [], dedup: true});
+    }
+    var entry = _scopeStacks[bucket][_scopeStacks[bucket].length - 1];
+    if (entry.emitted.indexOf(value) === -1) entry.emitted.push(value);
+  }
+  function sxCollected(bucket) {
+    return sxEmitted(bucket);
+  }
+  function sxClearCollected(bucket) {
+    if (_scopeStacks[bucket] && _scopeStacks[bucket].length) {
+      _scopeStacks[bucket][_scopeStacks[bucket].length - 1].emitted = [];
+    }
+  }
 
   function lambdaParams(f) { return f.params; }
   function lambdaBody(f) { return f.body; }
@@ -3244,6 +3256,8 @@ def public_api_js(has_html, has_sx, has_dom, has_engine, has_orch, has_boot, has
     api_lines.append('    collect: sxCollect,')
     api_lines.append('    collected: sxCollected,')
     api_lines.append('    clearCollected: sxClearCollected,')
+    api_lines.append('    scopePush: scopePush,')
+    api_lines.append('    scopePop: scopePop,')
     api_lines.append('    providePush: providePush,')
     api_lines.append('    providePop: providePop,')
     api_lines.append('    context: sxContext,')

shared/sx/ref/platform_py.py

@@ -91,51 +91,56 @@ class _Spread:
         self.attrs = dict(attrs) if attrs else {}
 
 
-# Render-time accumulator buckets (per render pass)
-_collect_buckets: dict[str, list] = {}
+# Unified scope stacks — backing store for provide/context/emit!/collect!
+# Each entry: {"value": v, "emitted": [], "dedup": bool}
+_scope_stacks: dict[str, list[dict]] = {}
 
 
 def _collect_reset():
-    """Reset all collect buckets (call at start of each render pass)."""
-    global _collect_buckets
-    _collect_buckets = {}
+    """Reset all scope stacks (call at start of each render pass)."""
+    global _scope_stacks
+    _scope_stacks = {}
 
 
-# Render-time dynamic scope stacks (provide/context/emit!)
-_provide_stacks: dict[str, list[dict]] = {}
+def scope_push(name, value=None):
+    """Push a scope with name, value, and empty accumulator."""
+    _scope_stacks.setdefault(name, []).append({"value": value, "emitted": [], "dedup": False})
 
 
-def provide_push(name, value=None):
-    """Push a provider scope with name, value, and empty emitted list."""
-    _provide_stacks.setdefault(name, []).append({"value": value, "emitted": []})
+def scope_pop(name):
+    """Pop the most recent scope for name."""
+    if name in _scope_stacks and _scope_stacks[name]:
+        _scope_stacks[name].pop()
 
 
-def provide_pop(name):
-    """Pop the most recent provider scope for name."""
-    if name in _provide_stacks and _provide_stacks[name]:
-        _provide_stacks[name].pop()
+# Aliases — provide-push!/provide-pop! map to scope-push!/scope-pop!
+provide_push = scope_push
+provide_pop = scope_pop
 
 
 def sx_context(name, *default):
-    """Read value from nearest enclosing provider. Error if no provider and no default."""
-    if name in _provide_stacks and _provide_stacks[name]:
-        return _provide_stacks[name][-1]["value"]
+    """Read value from nearest enclosing scope. Error if no scope and no default."""
+    if name in _scope_stacks and _scope_stacks[name]:
+        return _scope_stacks[name][-1]["value"]
     if default:
         return default[0]
     raise RuntimeError(f"No provider for: {name}")
 
 
 def sx_emit(name, value):
-    """Append value to nearest enclosing provider's accumulator. No-op if no provider."""
-    if name in _provide_stacks and _provide_stacks[name]:
-        _provide_stacks[name][-1]["emitted"].append(value)
+    """Append value to nearest enclosing scope's accumulator. Respects dedup flag."""
+    if name in _scope_stacks and _scope_stacks[name]:
+        entry = _scope_stacks[name][-1]
+        if entry["dedup"] and value in entry["emitted"]:
+            return NIL
+        entry["emitted"].append(value)
     return NIL
 
 
 def sx_emitted(name):
-    """Return list of values emitted into nearest matching provider."""
-    if name in _provide_stacks and _provide_stacks[name]:
-        return list(_provide_stacks[name][-1]["emitted"])
+    """Return list of values emitted into nearest matching scope."""
+    if name in _scope_stacks and _scope_stacks[name]:
+        return list(_scope_stacks[name][-1]["emitted"])
     return []
 
 
@@ -340,23 +345,23 @@ def spread_attrs(s):
 
 
 def sx_collect(bucket, value):
-    """Add value to named render-time accumulator (deduplicated)."""
-    if bucket not in _collect_buckets:
-        _collect_buckets[bucket] = []
-    items = _collect_buckets[bucket]
-    if value not in items:
-        items.append(value)
+    """Add value to named scope accumulator (deduplicated). Lazily creates root scope."""
+    if bucket not in _scope_stacks or not _scope_stacks[bucket]:
+        _scope_stacks.setdefault(bucket, []).append({"value": None, "emitted": [], "dedup": True})
+    entry = _scope_stacks[bucket][-1]
+    if value not in entry["emitted"]:
+        entry["emitted"].append(value)
 
 
 def sx_collected(bucket):
-    """Return all values in named render-time accumulator."""
-    return list(_collect_buckets.get(bucket, []))
+    """Return all values collected in named scope accumulator."""
+    return sx_emitted(bucket)
 
 
 def sx_clear_collected(bucket):
-    """Clear a named render-time accumulator bucket."""
-    if bucket in _collect_buckets:
-        _collect_buckets[bucket] = []
+    """Clear nearest scope's accumulator for name."""
+    if bucket in _scope_stacks and _scope_stacks[bucket]:
+        _scope_stacks[bucket][-1]["emitted"] = []
 
 
 def lambda_params(f):
@@ -974,14 +979,17 @@ PRIMITIVES["assert"] = lambda cond, msg="Assertion failed": (_ for _ in ()).thro
 ''',
 
     "stdlib.spread": '''
-# stdlib.spread — spread + collect primitives
+# stdlib.spread — spread + collect + scope primitives
 PRIMITIVES["make-spread"] = make_spread
 PRIMITIVES["spread?"] = is_spread
 PRIMITIVES["spread-attrs"] = spread_attrs
 PRIMITIVES["collect!"] = sx_collect
 PRIMITIVES["collected"] = sx_collected
 PRIMITIVES["clear-collected!"] = sx_clear_collected
-# provide/context/emit! — render-time dynamic scope
+# scope — unified render-time dynamic scope
+PRIMITIVES["scope-push!"] = scope_push
+PRIMITIVES["scope-pop!"] = scope_pop
+# provide-push!/provide-pop! — aliases for scope-push!/scope-pop!
 PRIMITIVES["provide-push!"] = provide_push
 PRIMITIVES["provide-pop!"] = provide_pop
 PRIMITIVES["context"] = sx_context

shared/sx/ref/py.sx

@@ -252,6 +252,8 @@
   "collect!" "sx_collect"
   "collected" "sx_collected"
   "clear-collected!" "sx_clear_collected"
+  "scope-push!" "scope_push"
+  "scope-pop!" "scope_pop"
   "provide-push!" "provide_push"
   "provide-pop!" "provide_pop"
   "context" "sx_context"

shared/sx/ref/render.sx

@@ -269,11 +269,13 @@
 ;;   (collected bucket)        → list
 ;;   (clear-collected! bucket) → void
 ;;
-;; Dynamic scope (provide/context/emit!):
-;;   (provide-push! name val)  → void
-;;   (provide-pop! name)       → void
-;;   (context name &rest def)  → value from nearest provider
-;;   (emit! name value)        → void (append to provider accumulator)
+;; Scoped effects (scope/provide/context/emit!):
+;;   (scope-push! name val)    → void (general form)
+;;   (scope-pop! name)         → void (general form)
+;;   (provide-push! name val)  → alias for scope-push!
+;;   (provide-pop! name)       → alias for scope-pop!
+;;   (context name &rest def)  → value from nearest scope
+;;   (emit! name value)        → void (append to scope accumulator)
 ;;   (emitted name)            → list of emitted values
 ;;
 ;; From parser.sx:

shared/sx/ref/sx_ref.py

@@ -50,51 +50,56 @@ class _Spread:
         self.attrs = dict(attrs) if attrs else {}
 
 
-# Render-time accumulator buckets (per render pass)
-_collect_buckets: dict[str, list] = {}
+# Unified scope stacks — backing store for provide/context/emit!/collect!
+# Each entry: {"value": v, "emitted": [], "dedup": bool}
+_scope_stacks: dict[str, list[dict]] = {}
 
 
 def _collect_reset():
-    """Reset all collect buckets (call at start of each render pass)."""
-    global _collect_buckets
-    _collect_buckets = {}
+    """Reset all scope stacks (call at start of each render pass)."""
+    global _scope_stacks
+    _scope_stacks = {}
 
 
-# Render-time dynamic scope stacks (provide/context/emit!)
-_provide_stacks: dict[str, list[dict]] = {}
+def scope_push(name, value=None):
+    """Push a scope with name, value, and empty accumulator."""
+    _scope_stacks.setdefault(name, []).append({"value": value, "emitted": [], "dedup": False})
 
 
-def provide_push(name, value=None):
-    """Push a provider scope with name, value, and empty emitted list."""
-    _provide_stacks.setdefault(name, []).append({"value": value, "emitted": []})
+def scope_pop(name):
+    """Pop the most recent scope for name."""
+    if name in _scope_stacks and _scope_stacks[name]:
+        _scope_stacks[name].pop()
 
 
-def provide_pop(name):
-    """Pop the most recent provider scope for name."""
-    if name in _provide_stacks and _provide_stacks[name]:
-        _provide_stacks[name].pop()
+# Aliases — provide-push!/provide-pop! map to scope-push!/scope-pop!
+provide_push = scope_push
+provide_pop = scope_pop
 
 
 def sx_context(name, *default):
-    """Read value from nearest enclosing provider. Error if no provider and no default."""
-    if name in _provide_stacks and _provide_stacks[name]:
-        return _provide_stacks[name][-1]["value"]
+    """Read value from nearest enclosing scope. Error if no scope and no default."""
+    if name in _scope_stacks and _scope_stacks[name]:
+        return _scope_stacks[name][-1]["value"]
     if default:
         return default[0]
     raise RuntimeError(f"No provider for: {name}")
 
 
 def sx_emit(name, value):
-    """Append value to nearest enclosing provider's accumulator. No-op if no provider."""
-    if name in _provide_stacks and _provide_stacks[name]:
-        _provide_stacks[name][-1]["emitted"].append(value)
+    """Append value to nearest enclosing scope's accumulator. Respects dedup flag."""
+    if name in _scope_stacks and _scope_stacks[name]:
+        entry = _scope_stacks[name][-1]
+        if entry["dedup"] and value in entry["emitted"]:
+            return NIL
+        entry["emitted"].append(value)
     return NIL
 
 
 def sx_emitted(name):
-    """Return list of values emitted into nearest matching provider."""
-    if name in _provide_stacks and _provide_stacks[name]:
-        return list(_provide_stacks[name][-1]["emitted"])
+    """Return list of values emitted into nearest matching scope."""
+    if name in _scope_stacks and _scope_stacks[name]:
+        return list(_scope_stacks[name][-1]["emitted"])
     return []
 
 
@@ -299,23 +304,23 @@ def spread_attrs(s):
 
 
 def sx_collect(bucket, value):
-    """Add value to named render-time accumulator (deduplicated)."""
-    if bucket not in _collect_buckets:
-        _collect_buckets[bucket] = []
-    items = _collect_buckets[bucket]
-    if value not in items:
-        items.append(value)
+    """Add value to named scope accumulator (deduplicated). Lazily creates root scope."""
+    if bucket not in _scope_stacks or not _scope_stacks[bucket]:
+        _scope_stacks.setdefault(bucket, []).append({"value": None, "emitted": [], "dedup": True})
+    entry = _scope_stacks[bucket][-1]
+    if value not in entry["emitted"]:
+        entry["emitted"].append(value)
 
 
 def sx_collected(bucket):
-    """Return all values in named render-time accumulator."""
-    return list(_collect_buckets.get(bucket, []))
+    """Return all values collected in named scope accumulator."""
+    return sx_emitted(bucket)
 
 
 def sx_clear_collected(bucket):
-    """Clear a named render-time accumulator bucket."""
-    if bucket in _collect_buckets:
-        _collect_buckets[bucket] = []
+    """Clear nearest scope's accumulator for name."""
+    if bucket in _scope_stacks and _scope_stacks[bucket]:
+        _scope_stacks[bucket][-1]["emitted"] = []
 
 
 def lambda_params(f):
@@ -937,14 +942,17 @@ def _strip_tags(s):
 PRIMITIVES["assert"] = lambda cond, msg="Assertion failed": (_ for _ in ()).throw(RuntimeError(f"Assertion error: {msg}")) if not sx_truthy(cond) else True
 
 
-# stdlib.spread — spread + collect primitives
+# stdlib.spread — spread + collect + scope primitives
 PRIMITIVES["make-spread"] = make_spread
 PRIMITIVES["spread?"] = is_spread
 PRIMITIVES["spread-attrs"] = spread_attrs
 PRIMITIVES["collect!"] = sx_collect
 PRIMITIVES["collected"] = sx_collected
 PRIMITIVES["clear-collected!"] = sx_clear_collected
-# provide/context/emit! — render-time dynamic scope
+# scope — unified render-time dynamic scope
+PRIMITIVES["scope-push!"] = scope_push
+PRIMITIVES["scope-pop!"] = scope_pop
+# provide-push!/provide-pop! — aliases for scope-push!/scope-pop!
 PRIMITIVES["provide-push!"] = provide_push
 PRIMITIVES["provide-pop!"] = provide_pop
 PRIMITIVES["context"] = sx_context
@@ -1394,6 +1402,8 @@ def eval_list(expr, env):
                 return sf_shift(args, env)
             elif sx_truthy((name == 'dynamic-wind')):
                 return sf_dynamic_wind(args, env)
+            elif sx_truthy((name == 'scope')):
+                return sf_scope(args, env)
             elif sx_truthy((name == 'provide')):
                 return sf_provide(args, env)
             elif sx_truthy((name == 'map')):
@@ -1887,6 +1897,25 @@ def sf_dynamic_wind(args, env):
     call_thunk(after, env)
     return result
 
+# sf-scope
+def sf_scope(args, env):
+    _cells = {}
+    name = trampoline(eval_expr(first(args), env))
+    rest = slice(args, 1)
+    val = NIL
+    body_exprs = NIL
+    if sx_truthy(((len(rest) >= 2) if not sx_truthy((len(rest) >= 2)) else ((type_of(first(rest)) == 'keyword') if not sx_truthy((type_of(first(rest)) == 'keyword')) else (keyword_name(first(rest)) == 'value')))):
+        val = trampoline(eval_expr(nth(rest, 1), env))
+        body_exprs = slice(rest, 2)
+    else:
+        body_exprs = rest
+    scope_push(name, val)
+    _cells['result'] = NIL
+    for e in body_exprs:
+        _cells['result'] = trampoline(eval_expr(e, env))
+    scope_pop(name)
+    return _cells['result']
+
 # sf-provide
 def sf_provide(args, env):
     _cells = {}
@@ -1894,10 +1923,10 @@ def sf_provide(args, env):
     val = trampoline(eval_expr(nth(args, 1), env))
     body_exprs = slice(args, 2)
     _cells['result'] = NIL
-    provide_push(name, val)
+    scope_push(name, val)
     for e in body_exprs:
         _cells['result'] = trampoline(eval_expr(e, env))
-    provide_pop(name)
+    scope_pop(name)
     return _cells['result']
 
 # expand-macro
@@ -2251,7 +2280,7 @@ def render_value_to_html(val, env):
         return escape_html(sx_str(val))
 
 # RENDER_HTML_FORMS
-RENDER_HTML_FORMS = ['if', 'when', 'cond', 'case', 'let', 'let*', 'begin', 'do', 'define', 'defcomp', 'defisland', 'defmacro', 'defstyle', 'defhandler', 'deftype', 'defeffect', 'map', 'map-indexed', 'filter', 'for-each', 'provide']
+RENDER_HTML_FORMS = ['if', 'when', 'cond', 'case', 'let', 'let*', 'begin', 'do', 'define', 'defcomp', 'defisland', 'defmacro', 'defstyle', 'defhandler', 'deftype', 'defeffect', 'map', 'map-indexed', 'filter', 'for-each', 'scope', 'provide']
 
 # render-html-form?
 def is_render_html_form(name):
@@ -2350,14 +2379,28 @@ def dispatch_html_form(name, expr, env):
         f = trampoline(eval_expr(nth(expr, 1), env))
         coll = trampoline(eval_expr(nth(expr, 2), env))
         return join('', map(lambda item: (render_lambda_html(f, [item], env) if sx_truthy(is_lambda(f)) else render_to_html(apply(f, [item]), env)), coll))
+    elif sx_truthy((name == 'scope')):
+        scope_name = trampoline(eval_expr(nth(expr, 1), env))
+        rest_args = slice(expr, 2)
+        scope_val = NIL
+        body_exprs = NIL
+        if sx_truthy(((len(rest_args) >= 2) if not sx_truthy((len(rest_args) >= 2)) else ((type_of(first(rest_args)) == 'keyword') if not sx_truthy((type_of(first(rest_args)) == 'keyword')) else (keyword_name(first(rest_args)) == 'value')))):
+            scope_val = trampoline(eval_expr(nth(rest_args, 1), env))
+            body_exprs = slice(rest_args, 2)
+        else:
+            body_exprs = rest_args
+        scope_push(scope_name, scope_val)
+        result = (render_to_html(first(body_exprs), env) if sx_truthy((len(body_exprs) == 1)) else join('', map(lambda e: render_to_html(e, env), body_exprs)))
+        scope_pop(scope_name)
+        return result
     elif sx_truthy((name == 'provide')):
         prov_name = trampoline(eval_expr(nth(expr, 1), env))
         prov_val = trampoline(eval_expr(nth(expr, 2), env))
         body_start = 3
         body_count = (len(expr) - 3)
-        provide_push(prov_name, prov_val)
+        scope_push(prov_name, prov_val)
         result = (render_to_html(nth(expr, body_start), env) if sx_truthy((body_count == 1)) else join('', map(lambda i: render_to_html(nth(expr, i), env), range(body_start, (body_start + body_count)))))
-        provide_pop(prov_name)
+        scope_pop(prov_name)
         return result
     else:
         return render_value_to_html(trampoline(eval_expr(expr, env)), env)
@@ -2389,11 +2432,11 @@ def render_html_element(tag, args, env):
     if sx_truthy(is_void):
         return sx_str('<', tag, render_attrs(attrs), ' />')
     else:
-        provide_push('element-attrs', NIL)
+        scope_push('element-attrs', NIL)
         content = join('', map(lambda c: render_to_html(c, env), children))
         for spread_dict in sx_emitted('element-attrs'):
             merge_spread_attrs(attrs, spread_dict)
-        provide_pop('element-attrs')
+        scope_pop('element-attrs')
         return sx_str('<', tag, render_attrs(attrs), '>', content, '</', tag, '>')
 
 # render-html-lake
@@ -2404,11 +2447,11 @@ def render_html_lake(args, env):
     children = []
     reduce(lambda state, arg: (lambda skip: (assoc(state, 'skip', False, 'i', (get(state, 'i') + 1)) if sx_truthy(skip) else ((lambda kname: (lambda kval: _sx_begin((_sx_cell_set(_cells, 'lake_id', kval) if sx_truthy((kname == 'id')) else (_sx_cell_set(_cells, 'lake_tag', kval) if sx_truthy((kname == 'tag')) else NIL)), assoc(state, 'skip', True, 'i', (get(state, 'i') + 1))))(trampoline(eval_expr(nth(args, (get(state, 'i') + 1)), env))))(keyword_name(arg)) if sx_truthy(((type_of(arg) == 'keyword') if not sx_truthy((type_of(arg) == 'keyword')) else ((get(state, 'i') + 1) < len(args)))) else _sx_begin(_sx_append(children, arg), assoc(state, 'i', (get(state, 'i') + 1))))))(get(state, 'skip')), {'i': 0, 'skip': False}, args)
     lake_attrs = {'data-sx-lake': (_cells['lake_id'] if sx_truthy(_cells['lake_id']) else '')}
-    provide_push('element-attrs', NIL)
+    scope_push('element-attrs', NIL)
     content = join('', map(lambda c: render_to_html(c, env), children))
     for spread_dict in sx_emitted('element-attrs'):
         merge_spread_attrs(lake_attrs, spread_dict)
-    provide_pop('element-attrs')
+    scope_pop('element-attrs')
     return sx_str('<', _cells['lake_tag'], render_attrs(lake_attrs), '>', content, '</', _cells['lake_tag'], '>')
 
 # render-html-marsh
@@ -2419,11 +2462,11 @@ def render_html_marsh(args, env):
     children = []
     reduce(lambda state, arg: (lambda skip: (assoc(state, 'skip', False, 'i', (get(state, 'i') + 1)) if sx_truthy(skip) else ((lambda kname: (lambda kval: _sx_begin((_sx_cell_set(_cells, 'marsh_id', kval) if sx_truthy((kname == 'id')) else (_sx_cell_set(_cells, 'marsh_tag', kval) if sx_truthy((kname == 'tag')) else (NIL if sx_truthy((kname == 'transform')) else NIL))), assoc(state, 'skip', True, 'i', (get(state, 'i') + 1))))(trampoline(eval_expr(nth(args, (get(state, 'i') + 1)), env))))(keyword_name(arg)) if sx_truthy(((type_of(arg) == 'keyword') if not sx_truthy((type_of(arg) == 'keyword')) else ((get(state, 'i') + 1) < len(args)))) else _sx_begin(_sx_append(children, arg), assoc(state, 'i', (get(state, 'i') + 1))))))(get(state, 'skip')), {'i': 0, 'skip': False}, args)
     marsh_attrs = {'data-sx-marsh': (_cells['marsh_id'] if sx_truthy(_cells['marsh_id']) else '')}
-    provide_push('element-attrs', NIL)
+    scope_push('element-attrs', NIL)
     content = join('', map(lambda c: render_to_html(c, env), children))
     for spread_dict in sx_emitted('element-attrs'):
         merge_spread_attrs(marsh_attrs, spread_dict)
-    provide_pop('element-attrs')
+    scope_pop('element-attrs')
     return sx_str('<', _cells['marsh_tag'], render_attrs(marsh_attrs), '>', content, '</', _cells['marsh_tag'], '>')
 
 # render-html-island
@@ -2529,7 +2572,7 @@ def aser_call(name, args, env):
     child_parts = []
     _cells['skip'] = False
     _cells['i'] = 0
-    provide_push('element-attrs', NIL)
+    scope_push('element-attrs', NIL)
     for arg in args:
         if sx_truthy(_cells['skip']):
             _cells['skip'] = False
@@ -2557,12 +2600,12 @@ def aser_call(name, args, env):
             v = dict_get(spread_dict, k)
             attr_parts.append(sx_str(':', k))
             attr_parts.append(serialize(v))
-    provide_pop('element-attrs')
+    scope_pop('element-attrs')
     parts = concat([name], attr_parts, child_parts)
     return sx_str('(', join(' ', parts), ')')
 
 # SPECIAL_FORM_NAMES
-SPECIAL_FORM_NAMES = ['if', 'when', 'cond', 'case', 'and', 'or', 'let', 'let*', 'lambda', 'fn', 'define', 'defcomp', 'defmacro', 'defstyle', 'defhandler', 'defpage', 'defquery', 'defaction', 'defrelation', 'begin', 'do', 'quote', 'quasiquote', '->', 'set!', 'letrec', 'dynamic-wind', 'defisland', 'deftype', 'defeffect', 'provide']
+SPECIAL_FORM_NAMES = ['if', 'when', 'cond', 'case', 'and', 'or', 'let', 'let*', 'lambda', 'fn', 'define', 'defcomp', 'defmacro', 'defstyle', 'defhandler', 'defpage', 'defquery', 'defaction', 'defrelation', 'begin', 'do', 'quote', 'quasiquote', '->', 'set!', 'letrec', 'dynamic-wind', 'defisland', 'deftype', 'defeffect', 'scope', 'provide']
 
 # HO_FORM_NAMES
 HO_FORM_NAMES = ['map', 'map-indexed', 'filter', 'reduce', 'some', 'every?', 'for-each']
@@ -2659,14 +2702,30 @@ def aser_special(name, expr, env):
     elif sx_truthy(((name == 'define') if sx_truthy((name == 'define')) else ((name == 'defcomp') if sx_truthy((name == 'defcomp')) else ((name == 'defmacro') if sx_truthy((name == 'defmacro')) else ((name == 'defstyle') if sx_truthy((name == 'defstyle')) else ((name == 'defhandler') if sx_truthy((name == 'defhandler')) else ((name == 'defpage') if sx_truthy((name == 'defpage')) else ((name == 'defquery') if sx_truthy((name == 'defquery')) else ((name == 'defaction') if sx_truthy((name == 'defaction')) else ((name == 'defrelation') if sx_truthy((name == 'defrelation')) else ((name == 'deftype') if sx_truthy((name == 'deftype')) else (name == 'defeffect')))))))))))):
         trampoline(eval_expr(expr, env))
         return NIL
+    elif sx_truthy((name == 'scope')):
+        scope_name = trampoline(eval_expr(first(args), env))
+        rest_args = rest(args)
+        scope_val = NIL
+        body_args = NIL
+        if sx_truthy(((len(rest_args) >= 2) if not sx_truthy((len(rest_args) >= 2)) else ((type_of(first(rest_args)) == 'keyword') if not sx_truthy((type_of(first(rest_args)) == 'keyword')) else (keyword_name(first(rest_args)) == 'value')))):
+            scope_val = trampoline(eval_expr(nth(rest_args, 1), env))
+            body_args = slice(rest_args, 2)
+        else:
+            body_args = rest_args
+        scope_push(scope_name, scope_val)
+        _cells['result'] = NIL
+        for body in body_args:
+            _cells['result'] = aser(body, env)
+        scope_pop(scope_name)
+        return _cells['result']
     elif sx_truthy((name == 'provide')):
         prov_name = trampoline(eval_expr(first(args), env))
         prov_val = trampoline(eval_expr(nth(args, 1), env))
         _cells['result'] = NIL
-        provide_push(prov_name, prov_val)
+        scope_push(prov_name, prov_val)
         for body in slice(args, 2):
             _cells['result'] = aser(body, env)
-        provide_pop(prov_name)
+        scope_pop(prov_name)
         return _cells['result']
     else:
         return trampoline(eval_expr(expr, env))
@@ -3701,12 +3760,12 @@ async def async_render_element(tag, args, env, ctx):
     else:
         token = (svg_context_set(True) if sx_truthy(((tag == 'svg') if sx_truthy((tag == 'svg')) else (tag == 'math'))) else NIL)
         content_parts = []
-        provide_push('element-attrs', NIL)
+        scope_push('element-attrs', NIL)
         for c in children:
             content_parts.append((await async_render(c, env, ctx)))
         for spread_dict in sx_emitted('element-attrs'):
             merge_spread_attrs(attrs, spread_dict)
-        provide_pop('element-attrs')
+        scope_pop('element-attrs')
         if sx_truthy(token):
             svg_context_reset(token)
         return sx_str('<', tag, render_attrs(attrs), '>', join('', content_parts), '</', tag, '>')
@@ -3798,7 +3857,7 @@ async def async_map_render(exprs, env, ctx):
     return results
 
 # ASYNC_RENDER_FORMS
-ASYNC_RENDER_FORMS = ['if', 'when', 'cond', 'case', 'let', 'let*', 'begin', 'do', 'define', 'defcomp', 'defisland', 'defmacro', 'defstyle', 'defhandler', 'deftype', 'defeffect', 'map', 'map-indexed', 'filter', 'for-each', 'provide']
+ASYNC_RENDER_FORMS = ['if', 'when', 'cond', 'case', 'let', 'let*', 'begin', 'do', 'define', 'defcomp', 'defisland', 'defmacro', 'defstyle', 'defhandler', 'deftype', 'defeffect', 'map', 'map-indexed', 'filter', 'for-each', 'scope', 'provide']
 
 # async-render-form?
 def async_render_form_p(name):
@@ -3859,14 +3918,28 @@ async def dispatch_async_render_form(name, expr, env, ctx):
         f = (await async_eval(nth(expr, 1), env, ctx))
         coll = (await async_eval(nth(expr, 2), env, ctx))
         return join('', (await async_map_fn_render(f, coll, env, ctx)))
+    elif sx_truthy((name == 'scope')):
+        scope_name = (await async_eval(nth(expr, 1), env, ctx))
+        rest_args = slice(expr, 2)
+        scope_val = NIL
+        body_exprs = NIL
+        if sx_truthy(((len(rest_args) >= 2) if not sx_truthy((len(rest_args) >= 2)) else ((type_of(first(rest_args)) == 'keyword') if not sx_truthy((type_of(first(rest_args)) == 'keyword')) else (keyword_name(first(rest_args)) == 'value')))):
+            scope_val = (await async_eval(nth(rest_args, 1), env, ctx))
+            body_exprs = slice(rest_args, 2)
+        else:
+            body_exprs = rest_args
+        scope_push(scope_name, scope_val)
+        result = ((await async_render(first(body_exprs), env, ctx)) if sx_truthy((len(body_exprs) == 1)) else join('', (await async_map_render(body_exprs, env, ctx))))
+        scope_pop(scope_name)
+        return result
     elif sx_truthy((name == 'provide')):
         prov_name = (await async_eval(nth(expr, 1), env, ctx))
         prov_val = (await async_eval(nth(expr, 2), env, ctx))
         body_start = 3
         body_count = (len(expr) - 3)
-        provide_push(prov_name, prov_val)
+        scope_push(prov_name, prov_val)
         result = ((await async_render(nth(expr, body_start), env, ctx)) if sx_truthy((body_count == 1)) else join('', (await async_map_render(slice(expr, body_start), env, ctx))))
-        provide_pop(prov_name)
+        scope_pop(prov_name)
         return result
     else:
         return (await async_render((await async_eval(expr, env, ctx)), env, ctx))
@@ -4149,7 +4222,7 @@ async def async_aser_call(name, args, env, ctx):
     child_parts = []
     _cells['skip'] = False
     _cells['i'] = 0
-    provide_push('element-attrs', NIL)
+    scope_push('element-attrs', NIL)
     for arg in args:
         if sx_truthy(_cells['skip']):
             _cells['skip'] = False
@@ -4188,14 +4261,14 @@ async def async_aser_call(name, args, env, ctx):
             v = dict_get(spread_dict, k)
             attr_parts.append(sx_str(':', k))
             attr_parts.append(serialize(v))
-    provide_pop('element-attrs')
+    scope_pop('element-attrs')
     if sx_truthy(token):
         svg_context_reset(token)
     parts = concat([name], attr_parts, child_parts)
     return make_sx_expr(sx_str('(', join(' ', parts), ')'))
 
 # ASYNC_ASER_FORM_NAMES
-ASYNC_ASER_FORM_NAMES = ['if', 'when', 'cond', 'case', 'and', 'or', 'let', 'let*', 'lambda', 'fn', 'define', 'defcomp', 'defmacro', 'defstyle', 'defhandler', 'defpage', 'defquery', 'defaction', 'begin', 'do', 'quote', '->', 'set!', 'defisland', 'deftype', 'defeffect', 'provide']
+ASYNC_ASER_FORM_NAMES = ['if', 'when', 'cond', 'case', 'and', 'or', 'let', 'let*', 'lambda', 'fn', 'define', 'defcomp', 'defmacro', 'defstyle', 'defhandler', 'defpage', 'defquery', 'defaction', 'begin', 'do', 'quote', '->', 'set!', 'defisland', 'deftype', 'defeffect', 'scope', 'provide']
 
 # ASYNC_ASER_HO_NAMES
 ASYNC_ASER_HO_NAMES = ['map', 'map-indexed', 'filter', 'for-each']
@@ -4289,14 +4362,30 @@ async def dispatch_async_aser_form(name, expr, env, ctx):
     elif sx_truthy(((name == 'define') if sx_truthy((name == 'define')) else ((name == 'defcomp') if sx_truthy((name == 'defcomp')) else ((name == 'defmacro') if sx_truthy((name == 'defmacro')) else ((name == 'defstyle') if sx_truthy((name == 'defstyle')) else ((name == 'defhandler') if sx_truthy((name == 'defhandler')) else ((name == 'defpage') if sx_truthy((name == 'defpage')) else ((name == 'defquery') if sx_truthy((name == 'defquery')) else ((name == 'defaction') if sx_truthy((name == 'defaction')) else ((name == 'deftype') if sx_truthy((name == 'deftype')) else (name == 'defeffect'))))))))))):
         (await async_eval(expr, env, ctx))
         return NIL
+    elif sx_truthy((name == 'scope')):
+        scope_name = (await async_eval(first(args), env, ctx))
+        rest_args = rest(args)
+        scope_val = NIL
+        body_args = NIL
+        if sx_truthy(((len(rest_args) >= 2) if not sx_truthy((len(rest_args) >= 2)) else ((type_of(first(rest_args)) == 'keyword') if not sx_truthy((type_of(first(rest_args)) == 'keyword')) else (keyword_name(first(rest_args)) == 'value')))):
+            scope_val = (await async_eval(nth(rest_args, 1), env, ctx))
+            body_args = slice(rest_args, 2)
+        else:
+            body_args = rest_args
+        scope_push(scope_name, scope_val)
+        _cells['result'] = NIL
+        for body in body_args:
+            _cells['result'] = (await async_aser(body, env, ctx))
+        scope_pop(scope_name)
+        return _cells['result']
     elif sx_truthy((name == 'provide')):
         prov_name = (await async_eval(first(args), env, ctx))
         prov_val = (await async_eval(nth(args, 1), env, ctx))
         _cells['result'] = NIL
-        provide_push(prov_name, prov_val)
+        scope_push(prov_name, prov_val)
         for body in slice(args, 2):
             _cells['result'] = (await async_aser(body, env, ctx))
-        provide_pop(prov_name)
+        scope_pop(prov_name)
         return _cells['result']
     else:
         return (await async_eval(expr, env, ctx))

shared/sx/ref/test-aser.sx

@@ -301,3 +301,46 @@
   (deftest "spread in non-element context silently drops"
     (assert-equal "hello"
       (render-sx "(do (make-spread {:class \"card\"}) \"hello\")"))))
+
+
+;; --------------------------------------------------------------------------
+;; Scope tests — unified scope primitive
+;; --------------------------------------------------------------------------
+
+(defsuite "scope"
+
+  (deftest "scope with value and context"
+    (assert-equal "dark"
+      (render-sx "(scope \"sc-theme\" :value \"dark\" (context \"sc-theme\"))")))
+
+  (deftest "scope without value defaults to nil"
+    (assert-equal ""
+      (render-sx "(scope \"sc-nil\" (str (context \"sc-nil\")))")))
+
+  (deftest "scope with emit!/emitted"
+    (assert-equal "a,b"
+      (render-sx "(scope \"sc-emit\" (emit! \"sc-emit\" \"a\") (emit! \"sc-emit\" \"b\") (join \",\" (emitted \"sc-emit\")))")))
+
+  (deftest "provide is equivalent to scope with value"
+    (assert-equal "42"
+      (render-sx "(provide \"sc-prov\" 42 (str (context \"sc-prov\")))")))
+
+  (deftest "collect! works via scope (lazy root scope)"
+    (assert-equal "x,y"
+      (render-sx "(do (collect! \"sc-coll\" \"x\") (collect! \"sc-coll\" \"y\") (join \",\" (collected \"sc-coll\")))")))
+
+  (deftest "collect! deduplicates"
+    (assert-equal "a"
+      (render-sx "(do (collect! \"sc-dedup\" \"a\") (collect! \"sc-dedup\" \"a\") (join \",\" (collected \"sc-dedup\")))")))
+
+  (deftest "clear-collected! clears scope accumulator"
+    (assert-equal ""
+      (render-sx "(do (collect! \"sc-clear\" \"x\") (clear-collected! \"sc-clear\") (join \",\" (collected \"sc-clear\")))")))
+
+  (deftest "nested scope shadows outer"
+    (assert-equal "inner"
+      (render-sx "(scope \"sc-nest\" :value \"outer\" (scope \"sc-nest\" :value \"inner\" (context \"sc-nest\")))")))
+
+  (deftest "scope pops correctly after body"
+    (assert-equal "outer"
+      (render-sx "(scope \"sc-pop\" :value \"outer\" (scope \"sc-pop\" :value \"inner\" \"ignore\") (context \"sc-pop\"))"))))