Hyperscript: remove/tell/transition commands, test generator ref() fix

Parser: remove me/[@attr]/{css}, tell body scoping (skip then),
transition from/to syntax + my/style prefixes.
Compiler: remove-element, remove-attr, remove-css, transition-from.
Runtime: hs-transition-from for from/to CSS transitions.
Generator changes (already committed) fix ref() unnamed-first mapping,
assertion dedup for pre/post pairs, on-event then insertion.

Conformance: 374→395 (+21 tests, 48%)

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

lib/hyperscript/compiler.sx

@@ -240,18 +240,22 @@
           ((prop (nth ast 1)) (value (hs-to-sx (nth ast 2))))
           (if
             (= (len ast) 5)
-            (list
-              (quote hs-transition)
-              (hs-to-sx (nth ast 4))
-              prop
-              value
-              (nth ast 3))
-            (list
-              (quote hs-transition)
-              (hs-to-sx (nth ast 3))
-              prop
-              value
-              nil)))))
+            (let
+              ((raw-tgt (nth ast 4)))
+              (list
+                (quote hs-transition)
+                (if (nil? raw-tgt) (quote me) (hs-to-sx raw-tgt))
+                prop
+                value
+                (nth ast 3)))
+            (let
+              ((raw-tgt (nth ast 3)))
+              (list
+                (quote hs-transition)
+                (if (nil? raw-tgt) (quote me) (hs-to-sx raw-tgt))
+                prop
+                value
+                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)))

lib/hyperscript/parser.sx

@@ -1011,18 +1011,21 @@
         (fn
           ()
           (let
-            ((prop (get (adv!) "value")))
-            (expect-kw! "to")
+            ((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
-              ((value (parse-expr)))
+              ((from-val (if (match-kw "from") (parse-expr) nil)))
+              (expect-kw! "to")
               (let
-                ((dur (if (match-kw "over") (if (= (tp-type) "number") (parse-dur (get (adv!) "value")) 400) nil)))
+                ((value (parse-expr)))
                 (let
-                  ((tgt (parse-tgt-kw "on" (list (quote me)))))
+                  ((dur (if (match-kw "over") (parse-expr) nil)))
                   (if
-                    dur
-                    (list (quote transition) prop value dur tgt)
-                    (list (quote transition) prop value tgt))))))))
+                    from-val
+                    (list (quote transition-from) prop from-val value dur)
+                    (if
+                      dur
+                      (list (quote transition) prop value dur nil)
+                      (list (quote transition) prop value nil)))))))))
       (define
         parse-repeat-cmd
         (fn

lib/hyperscript/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)))))