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/canonical.sx

@@ -1,3 +1,4 @@
+;; Deterministic serialization for content addressing
 (define
   canonical-serialize
   :effects ()
@@ -23,6 +24,7 @@
       (canonical-dict val)
       :else (str val))))
 
+;; Normalize number representation (no trailing zeros)
 (define
   canonical-number
   :effects ()
@@ -40,6 +42,7 @@
             (if (ends-with? trimmed ".") (str trimmed "0") trimmed))
           s)))))
 
+;; Serialize dict with sorted keys
 (define
   canonical-dict
   :effects ()
@@ -61,16 +64,19 @@
             sorted-keys))
         "}"))))
 
+;; Compute SHA3-256 content ID from an expression
 (define
   content-id
   :effects ()
   (fn (expr) (sha3-256 (canonical-serialize expr))))
 
+;; First 16 chars of content ID (short form)
 (define
   content-id-short
   :effects ()
   (fn (expr) (slice (content-id expr) 0 16)))
 
+;; Create a bytecode module container
 (define
   make-bytecode-module
   :effects ()
@@ -78,6 +84,7 @@
     (version source-hash code)
     (list (quote sxbc) version source-hash code)))
 
+;; Type predicate for bytecode modules
 (define
   bytecode-module?
   :effects ()
@@ -85,12 +92,16 @@
     (expr)
     (and (list? expr) (>= (len expr) 4) (= (first expr) (quote sxbc)))))
 
+;; Get module format version
 (define bytecode-module-version :effects () (fn (m) (nth m 1)))
 
+;; Get source content hash
 (define bytecode-module-source-hash :effects () (fn (m) (nth m 2)))
 
+;; Get compiled bytecode
 (define bytecode-module-code :effects () (fn (m) (nth m 3)))
 
+;; Create a code object (arity + constants + bytecode)
 (define
   make-code-object
   :effects ()
@@ -104,6 +115,7 @@
         (set! parts (concat parts (list :upvalue-count upvalue-count))))
       (concat parts (list :bytecode bytecode :constants constants)))))
 
+;; Create provenance record (author, timestamp, source)
 (define
   make-provenance
   :effects ()

spec/harness.sx

@@ -1,41 +1,62 @@
+;; Assert condition is truthy, error with message
 (define assert (fn (condition msg) (when (not condition) (error (or msg "Assertion failed")))))
 
+;; Assert two values are equal
 (define assert= (fn (actual expected msg) (when (not (= actual expected)) (error (or msg (str "Expected " expected ", got " actual))))))
 
+;; Dict of mock IO operations for testing
 (define default-platform {:current-user (fn () nil) :csrf-token (fn () "test-csrf-token") :app-url (fn (service &rest path) "/mock-app-url") :frag (fn (service comp &rest args) "") :sleep (fn (ms) nil) :local-storage-set (fn (key val) nil) :set-cookie (fn (name val &rest opts) nil) :url-for (fn (endpoint &rest args) "/mock-url") :create-element (fn (tag) nil) :request-path (fn () "/") :config (fn (key) nil) :set-attr (fn (el name val) nil) :set-text (fn (el text) nil) :remove-child (fn (parent child) nil) :fetch (fn (url &rest opts) {:status 200 :body "" :ok true}) :query (fn (service name &rest args) (list)) :add-class (fn (el cls) nil) :get-element (fn (id) nil) :now (fn () 0) :abort (fn (code) nil) :action (fn (service name &rest args) {:ok true}) :remove-class (fn (el cls) nil) :append-child (fn (parent child) nil) :request-arg (fn (name) nil) :emit-dom (fn (op &rest args) nil) :local-storage-get (fn (key) nil) :get-cookie (fn (name) nil)})
 
+;; Create a test session with mock IO platform
 (define make-harness :effects () (fn (&key platform) (let ((merged (if (nil? platform) default-platform (merge default-platform platform)))) {:log (list) :platform merged :state {:cookies {} :storage {} :dom nil}})))
 
+;; Clear IO log and state for a new test
 (define harness-reset! :effects () (fn (session) (dict-set! session "log" (list)) (dict-set! session "state" {:cookies {} :storage {} :dom nil}) session))
 
+;; Append an IO call record to session log
 (define harness-log :effects () (fn (session &key op) (let ((log (get session "log"))) (if (nil? op) log (filter (fn (entry) (= (get entry "op") op)) log)))))
 
+;; Read state value from session store
 (define harness-get :effects () (fn (session key) (get (get session "state") key)))
 
+;; Write state value to session store
 (define harness-set! :effects () (fn (session key value) (dict-set! (get session "state") key value) nil))
 
+;; Wrap a mock fn to record calls in the IO log
 (define make-interceptor :effects () (fn (session op-name mock-fn) (fn (&rest args) (let ((result (if (empty? args) (mock-fn) (if (= 1 (len args)) (mock-fn (first args)) (if (= 2 (len args)) (mock-fn (first args) (nth args 1)) (if (= 3 (len args)) (mock-fn (first args) (nth args 1) (nth args 2)) (apply mock-fn args)))))) (log (get session "log"))) (append! log {:args args :result result :op op-name}) result))))
 
+;; Bind all interceptors into the eval environment
 (define install-interceptors :effects () (fn (session env) (for-each (fn (key) (let ((mock-fn (get (get session "platform") key)) (interceptor (make-interceptor session key mock-fn))) (env-bind! env key interceptor))) (keys (get session "platform"))) env))
 
+;; Query IO log: all calls, or filtered by op name
 (define io-calls :effects () (fn (session op-name) (filter (fn (entry) (= (get entry "op") op-name)) (get session "log"))))
 
+;; Count IO calls, optionally filtered by op name
 (define io-call-count :effects () (fn (session op-name) (len (io-calls session op-name))))
 
+;; Get the nth IO call record
 (define io-call-nth :effects () (fn (session op-name n) (let ((calls (io-calls session op-name))) (if (< n (len calls)) (nth calls n) nil))))
 
+;; Get args from the nth call to an operation
 (define io-call-args :effects () (fn (session op-name n) (let ((call (io-call-nth session op-name n))) (if (nil? call) nil (get call "args")))))
 
+;; Get return value from the nth call to an operation
 (define io-call-result :effects () (fn (session op-name n) (let ((call (io-call-nth session op-name n))) (if (nil? call) nil (get call "result")))))
 
+;; Assert an IO operation was called at least once
 (define assert-io-called :effects () (fn (session op-name) (assert (> (io-call-count session op-name) 0) (str "Expected IO operation " op-name " to be called but it was not"))))
 
+;; Assert an IO operation was never called
 (define assert-no-io :effects () (fn (session op-name) (assert (= (io-call-count session op-name) 0) (str "Expected IO operation " op-name " not to be called but it was called " (io-call-count session op-name) " time(s)"))))
 
+;; Assert exact call count for an operation
 (define assert-io-count :effects () (fn (session op-name expected) (let ((actual (io-call-count session op-name))) (assert (= actual expected) (str "Expected " op-name " to be called " expected " time(s) but was called " actual " time(s)")))))
 
+;; Assert args of the nth call match expected
 (define assert-io-args :effects () (fn (session op-name n expected-args) (let ((actual (io-call-args session op-name n))) (assert (equal? actual expected-args) (str "Expected call " n " to " op-name " with args " (str expected-args) " but got " (str actual))))))
 
+;; Assert result of the nth call matches expected
 (define assert-io-result :effects () (fn (session op-name n expected) (let ((actual (io-call-result session op-name n))) (assert (equal? actual expected) (str "Expected call " n " to " op-name " to return " (str expected) " but got " (str actual))))))
 
+;; Assert a state key has the expected value
 (define assert-state :effects () (fn (session key expected) (let ((actual (harness-get session key))) (assert (equal? actual expected) (str "Expected state " key " to be " (str expected) " but got " (str actual))))))

spec/parser.sx

@@ -50,6 +50,7 @@
 ;; --------------------------------------------------------------------------
 ;; Returns a list of top-level AST expressions.
 
+;; Parse SX source string into AST
 (define sx-parse :effects []
   (fn ((source :as string))
     (let ((pos 0)
@@ -360,6 +361,7 @@
 ;; Serializer — AST → SX source text
 ;; --------------------------------------------------------------------------
 
+;; Serialize AST value back to SX source
 (define sx-serialize :effects []
   (fn (val)
     (case (type-of val)
@@ -376,6 +378,7 @@
       :else       (str val))))
 
 
+;; Serialize a dict to SX {:key val} format
 (define sx-serialize-dict :effects []
   (fn ((d :as dict))
     (str "{"

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)))

spec/signals.sx

@@ -1,17 +1,23 @@
+;; Create raw signal dict with value, subs, deps fields
 (define
   make-signal
   (fn
     (value)
     (dict "__signal" true "value" value "subscribers" (list) "deps" (list))))
 
+;; Type predicate for signals
 (define signal? (fn (x) (and (dict? x) (has-key? x "__signal"))))
 
+;; Read current value from signal
 (define signal-value (fn (s) (get s "value")))
 
+;; Write value to signal (no notification)
 (define signal-set-value! (fn (s v) (dict-set! s "value" v)))
 
+;; List of subscriber functions
 (define signal-subscribers (fn (s) (get s "subscribers")))
 
+;; Add a subscriber function
 (define
   signal-add-sub!
   (fn
@@ -20,6 +26,7 @@
       (not (contains? (get s "subscribers") f))
       (dict-set! s "subscribers" (append (get s "subscribers") (list f))))))
 
+;; Remove a subscriber function
 (define
   signal-remove-sub!
   (fn
@@ -29,15 +36,19 @@
       "subscribers"
       (filter (fn (sub) (not (identical? sub f))) (get s "subscribers")))))
 
+;; List of upstream signal dependencies
 (define signal-deps (fn (s) (get s "deps")))
 
+;; Set upstream dependencies
 (define signal-set-deps! (fn (s deps) (dict-set! s "deps" deps)))
 
+;; Create a reactive signal (user-facing constructor)
 (define
   signal
   :effects ()
   (fn ((initial-value :as any)) (make-signal initial-value)))
 
+;; Dereference a signal, returning its current value
 (define
   deref
   :effects ()
@@ -58,6 +69,7 @@
               (signal-add-sub! s notify-fn))))
         (signal-value s)))))
 
+;; Set signal to new value and notify subscribers
 (define
   reset!
   :effects (mutation)
@@ -72,6 +84,7 @@
           (signal-set-value! s value)
           (notify-subscribers s))))))
 
+;; Apply function to current value and reset
 (define
   swap!
   :effects (mutation)
@@ -87,6 +100,7 @@
           (signal-set-value! s new-val)
           (notify-subscribers s))))))
 
+;; Create a derived signal that auto-updates from dependencies
 (define
   computed
   :effects (mutation)
@@ -100,6 +114,7 @@
         (register-in-scope (fn () (dispose-computed s)))
         s))))
 
+;; Create a side-effect that runs when dependencies change
 (define
   effect
   :effects (mutation)
@@ -115,10 +130,13 @@
           (register-in-scope dispose-fn)
           dispose-fn)))))
 
+;; Nesting counter for batched updates
 (define *batch-depth* 0)
 
+;; Queued notifications during batch
 (define *batch-queue* (list))
 
+;; Batch multiple signal updates, notify once at end
 (define
   batch
   :effects (mutation)
@@ -148,6 +166,7 @@
             queue)
           (for-each (fn ((sub :as lambda)) (sub)) pending))))))
 
+;; Notify all subscribers of a signal change
 (define
   notify-subscribers
   :effects (mutation)
@@ -158,6 +177,7 @@
       (when (not (contains? *batch-queue* s)) (append! *batch-queue* s))
       (flush-subscribers s))))
 
+;; Process queued subscriber notifications
 (define
   flush-subscribers
   :effects (mutation)
@@ -165,6 +185,7 @@
     ((s :as dict))
     (for-each (fn (sub) (cek-call sub nil)) (signal-subscribers s))))
 
+;; Tear down a computed signal, remove from deps
 (define
   dispose-computed
   :effects (mutation)
@@ -177,6 +198,7 @@
         (signal-deps s))
       (signal-set-deps! s (list)))))
 
+;; Evaluate body in an island disposal scope
 (define
   with-island-scope
   :effects (mutation)
@@ -185,6 +207,7 @@
     (scope-push! "sx-island-scope" scope-fn)
     (let ((result (body-fn))) (scope-pop! "sx-island-scope") result)))
 
+;; Register a disposable in the current island scope
 (define
   register-in-scope
   :effects (mutation)