Add one-line comments to all defines in 5 spec files

parser.sx (3), render.sx (15), harness.sx (21), signals.sx (23),
canonical.sx (12) — 74 comments total. Each define now has a ;;
comment explaining its purpose.

Combined with the evaluator.sx commit, all 215 defines across 6 spec
files are now documented. primitives.sx and special-forms.sx already
had :doc fields.

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

spec/render.sx

@@ -1,3 +1,4 @@
+;; Registry of all valid HTML tag names
 (define
   HTML_TAGS
   (list
@@ -141,6 +142,7 @@
     "dialog"
     "menu"))
 
+;; Self-closing tags (br, img, hr, etc.)
 (define
   VOID_ELEMENTS
   (list
@@ -159,6 +161,7 @@
     "track"
     "wbr"))
 
+;; Attrs that are true/false (checked, disabled, etc.)
 (define
   BOOLEAN_ATTRS
   (list
@@ -186,8 +189,10 @@
     "reversed"
     "selected"))
 
+;; Extensible list of forms treated as definitions
 (define *definition-form-extensions* (list))
 
+;; Check if a symbol names a definition form
 (define
   definition-form?
   :effects ()
@@ -203,6 +208,7 @@
       (= name "defeffect")
       (contains? *definition-form-extensions* name))))
 
+;; Parse keyword attrs and children from element arg list
 (define
   parse-element-args
   :effects (render)
@@ -233,6 +239,7 @@
         args)
       (list attrs children))))
 
+;; Render attr dict to HTML attribute string
 (define
   render-attrs
   :effects ()
@@ -255,6 +262,7 @@
               :else (str " " key "=\"" (escape-attr (str val)) "\""))))
         (keys attrs)))))
 
+;; Evaluate cond expression (dispatches to scheme/clojure style)
 (define
   eval-cond
   :effects ()
@@ -265,6 +273,7 @@
       (eval-cond-scheme clauses env)
       (eval-cond-clojure clauses env))))
 
+;; Scheme-style cond: ((test body) ...)
 (define
   eval-cond-scheme
   :effects ()
@@ -285,6 +294,7 @@
             body
             (eval-cond-scheme (rest clauses) env)))))))
 
+;; Clojure-style cond: (test body test body ...)
 (define
   eval-cond-clojure
   :effects ()
@@ -303,6 +313,7 @@
             body
             (eval-cond-clojure (slice clauses 2) env)))))))
 
+;; Evaluate let binding pairs, extend env
 (define
   process-bindings
   :effects (mutation)
@@ -324,6 +335,7 @@
         bindings)
       local)))
 
+;; Check if an expression should be rendered vs evaluated
 (define
   is-render-expr?
   :effects ()
@@ -350,6 +362,7 @@
                 (> (len expr) 1)
                 (= (type-of (nth expr 1)) "keyword")))))))))
 
+;; Merge spread child attrs into parent element attrs
 (define
   merge-spread-attrs
   :effects (mutation)
@@ -385,6 +398,7 @@
               (dict-set! target key val)))))
       (keys spread-dict))))
 
+;; Escape special chars for HTML text content
 (define
   escape-html
   (fn
@@ -397,4 +411,5 @@
       (set! r (replace r "\"" """))
       r)))
 
+;; Escape special chars for HTML attribute values
 (define escape-attr (fn (s) (escape-html s)))