From cdee007185fd62e9b81c1c633ebfad81a794f302 Mon Sep 17 00:00:00 2001
From: giles <giles.bradshaw@rose-ash.com>
Date: Sat, 25 Apr 2026 18:26:58 +0000
Subject: [PATCH] cl: Phase 1 lambda-list parser + 31 tests (172 total green)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
---
 lib/common-lisp/parser.sx       | 118 ++++++++++++++++++
 lib/common-lisp/tests/lambda.sx | 204 ++++++++++++++++++++++++++++++++
 plans/common-lisp-on-sx.md      |   5 +-
 3 files changed, 325 insertions(+), 2 deletions(-)
 create mode 100644 lib/common-lisp/tests/lambda.sx

diff --git a/lib/common-lisp/parser.sx b/lib/common-lisp/parser.sx
index b34867fa..c5724aa1 100644
--- a/lib/common-lisp/parser.sx
+++ b/lib/common-lisp/parser.sx
@@ -227,6 +227,124 @@
                   (get item "rest")
                   (concat acc (list (get item "form"))))))))))))
 
+;; ── lambda-list parser ───────────────────────────────────────────
+;;
+;; (cl-parse-lambda-list forms) — parse a list of CL forms (already read)
+;; into a structured dict:
+;;   {:required (list sym ...)
+;;    :optional (list {:name N :default D :supplied S} ...)
+;;    :rest     nil | "SYM"
+;;    :key      (list {:name N :keyword K :default D :supplied S} ...)
+;;    :allow-other-keys false | true
+;;    :aux      (list {:name N :init I} ...)}
+;;
+;; Symbols arrive as SX strings (upcase). &-markers are strings like "&OPTIONAL".
+;; Key params: keyword is the upcase name string; caller uses it as :keyword.
+;; Supplied-p: nil when absent.
+
+(define
+  cl-parse-opt-spec
+  (fn
+    (spec)
+    (if
+      (list? spec)
+      {:name (nth spec 0)
+        :default (if (> (len spec) 1) (nth spec 1) nil)
+        :supplied (if (> (len spec) 2) (nth spec 2) nil)}
+      {:name spec :default nil :supplied nil})))
+
+(define
+  cl-parse-key-spec
+  (fn
+    (spec)
+    (if
+      (list? spec)
+      (let
+        ((first (nth spec 0)))
+        (if
+          (list? first)
+          ;; ((:keyword var) default supplied-p)
+          {:name (nth first 1)
+            :keyword (get first "name")
+            :default (if (> (len spec) 1) (nth spec 1) nil)
+            :supplied (if (> (len spec) 2) (nth spec 2) nil)}
+          ;; (var default supplied-p)
+          {:name first
+            :keyword first
+            :default (if (> (len spec) 1) (nth spec 1) nil)
+            :supplied (if (> (len spec) 2) (nth spec 2) nil)}))
+      {:name spec :keyword spec :default nil :supplied nil})))
+
+(define
+  cl-parse-aux-spec
+  (fn
+    (spec)
+    (if
+      (list? spec)
+      {:name (nth spec 0) :init (if (> (len spec) 1) (nth spec 1) nil)}
+      {:name spec :init nil})))
+
+(define
+  cl-parse-lambda-list
+  (fn
+    (forms)
+    (let
+      ((state "required")
+        (required (list))
+        (optional (list))
+        (rest-name nil)
+        (key (list))
+        (allow-other-keys false)
+        (aux (list)))
+
+      (define
+        scan
+        (fn
+          (items)
+          (when
+            (> (len items) 0)
+            (let
+              ((item (nth items 0)) (tail (rest items)))
+              (cond
+                ((= item "&OPTIONAL")
+                  (do (set! state "optional") (scan tail)))
+                ((= item "&REST")
+                  (do (set! state "rest") (scan tail)))
+                ((= item "&BODY")
+                  (do (set! state "rest") (scan tail)))
+                ((= item "&KEY")
+                  (do (set! state "key") (scan tail)))
+                ((= item "&AUX")
+                  (do (set! state "aux") (scan tail)))
+                ((= item "&ALLOW-OTHER-KEYS")
+                  (do (set! allow-other-keys true) (scan tail)))
+                ((= state "required")
+                  (do (append! required item) (scan tail)))
+                ((= state "optional")
+                  (do (append! optional (cl-parse-opt-spec item)) (scan tail)))
+                ((= state "rest")
+                  (do (set! rest-name item) (set! state "done") (scan tail)))
+                ((= state "key")
+                  (do (append! key (cl-parse-key-spec item)) (scan tail)))
+                ((= state "aux")
+                  (do (append! aux (cl-parse-aux-spec item)) (scan tail)))
+                (:else (scan tail)))))))
+
+      (scan forms)
+      {:required required
+        :optional optional
+        :rest rest-name
+        :key key
+        :allow-other-keys allow-other-keys
+        :aux aux})))
+
+;; Convenience: parse lambda list from a CL source string
+(define
+  cl-parse-lambda-list-str
+  (fn
+    (src)
+    (cl-parse-lambda-list (cl-read src))))
+
 ;; ── public API ────────────────────────────────────────────────────
 
 (define
diff --git a/lib/common-lisp/tests/lambda.sx b/lib/common-lisp/tests/lambda.sx
new file mode 100644
index 00000000..134f3963
--- /dev/null
+++ b/lib/common-lisp/tests/lambda.sx
@@ -0,0 +1,204 @@
+;; Lambda list parser tests
+
+(define cl-test-pass 0)
+(define cl-test-fail 0)
+(define cl-test-fails (list))
+
+;; Deep structural equality for dicts and lists
+(define
+  cl-deep=
+  (fn
+    (a b)
+    (cond
+      ((= a b) true)
+      ((and (dict? a) (dict? b))
+        (let
+          ((ak (keys a)) (bk (keys b)))
+          (if
+            (not (= (len ak) (len bk)))
+            false
+            (every?
+              (fn (k) (and (has-key? b k) (cl-deep= (get a k) (get b k))))
+              ak))))
+      ((and (list? a) (list? b))
+        (if
+          (not (= (len a) (len b)))
+          false
+          (let
+            ((i 0) (ok true))
+            (define
+              chk
+              (fn
+                ()
+                (when
+                  (and ok (< i (len a)))
+                  (do
+                    (when
+                      (not (cl-deep= (nth a i) (nth b i)))
+                      (set! ok false))
+                    (set! i (+ i 1))
+                    (chk)))))
+            (chk)
+            ok)))
+      (:else false))))
+
+(define
+  cl-test
+  (fn
+    (name actual expected)
+    (if
+      (cl-deep= actual expected)
+      (set! cl-test-pass (+ cl-test-pass 1))
+      (do
+        (set! cl-test-fail (+ cl-test-fail 1))
+        (append! cl-test-fails {:name name :expected expected :actual actual})))))
+
+;; Helper: parse lambda list from string "(x y ...)"
+(define ll (fn (src) (cl-parse-lambda-list-str src)))
+(define ll-req  (fn (src) (get (ll src) "required")))
+(define ll-opt  (fn (src) (get (ll src) "optional")))
+(define ll-rest (fn (src) (get (ll src) "rest")))
+(define ll-key  (fn (src) (get (ll src) "key")))
+(define ll-aok  (fn (src) (get (ll src) "allow-other-keys")))
+(define ll-aux  (fn (src) (get (ll src) "aux")))
+
+;; ── required parameters ───────────────────────────────────────────
+
+(cl-test "required: empty" (ll-req "()") (list))
+(cl-test "required: one" (ll-req "(x)") (list "X"))
+(cl-test "required: two" (ll-req "(x y)") (list "X" "Y"))
+(cl-test "required: three" (ll-req "(a b c)") (list "A" "B" "C"))
+(cl-test "required: upcased" (ll-req "(foo bar)") (list "FOO" "BAR"))
+
+;; ── &optional ─────────────────────────────────────────────────────
+
+(cl-test "optional: none" (ll-opt "(x)") (list))
+
+(cl-test
+  "optional: bare symbol"
+  (ll-opt "(x &optional z)")
+  (list {:name "Z" :default nil :supplied nil}))
+
+(cl-test
+  "optional: with default"
+  (ll-opt "(x &optional (z 0))")
+  (list {:name "Z" :default 0 :supplied nil}))
+
+(cl-test
+  "optional: with supplied-p"
+  (ll-opt "(x &optional (z 0 z-p))")
+  (list {:name "Z" :default 0 :supplied "Z-P"}))
+
+(cl-test
+  "optional: two params"
+  (ll-opt "(&optional a (b 1))")
+  (list {:name "A" :default nil :supplied nil} {:name "B" :default 1 :supplied nil}))
+
+(cl-test
+  "optional: string default"
+  (ll-opt "(&optional (name \"world\"))")
+  (list {:name "NAME" :default "world" :supplied nil}))
+
+;; ── &rest ─────────────────────────────────────────────────────────
+
+(cl-test "rest: none" (ll-rest "(x)") nil)
+(cl-test "rest: present" (ll-rest "(x &rest args)") "ARGS")
+(cl-test "rest: with required" (ll-rest "(a b &rest tail)") "TAIL")
+
+;; &body is an alias for &rest
+(cl-test "body: alias for rest" (ll-rest "(&body forms)") "FORMS")
+
+;; rest doesn't consume required params
+(cl-test "rest: required still there" (ll-req "(a b &rest rest)") (list "A" "B"))
+
+;; ── &key ──────────────────────────────────────────────────────────
+
+(cl-test "key: none" (ll-key "(x)") (list))
+
+(cl-test
+  "key: bare symbol"
+  (ll-key "(&key x)")
+  (list {:name "X" :keyword "X" :default nil :supplied nil}))
+
+(cl-test
+  "key: with default"
+  (ll-key "(&key (x 42))")
+  (list {:name "X" :keyword "X" :default 42 :supplied nil}))
+
+(cl-test
+  "key: with supplied-p"
+  (ll-key "(&key (x 42 x-p))")
+  (list {:name "X" :keyword "X" :default 42 :supplied "X-P"}))
+
+(cl-test
+  "key: two params"
+  (ll-key "(&key a b)")
+  (list
+    {:name "A" :keyword "A" :default nil :supplied nil}
+    {:name "B" :keyword "B" :default nil :supplied nil}))
+
+;; ── &allow-other-keys ─────────────────────────────────────────────
+
+(cl-test "aok: absent" (ll-aok "(x)") false)
+(cl-test "aok: present" (ll-aok "(&key x &allow-other-keys)") true)
+
+;; ── &aux ──────────────────────────────────────────────────────────
+
+(cl-test "aux: none" (ll-aux "(x)") (list))
+
+(cl-test
+  "aux: bare symbol"
+  (ll-aux "(&aux temp)")
+  (list {:name "TEMP" :init nil}))
+
+(cl-test
+  "aux: with init"
+  (ll-aux "(&aux (count 0))")
+  (list {:name "COUNT" :init 0}))
+
+(cl-test
+  "aux: two vars"
+  (ll-aux "(&aux a (b 1))")
+  (list {:name "A" :init nil} {:name "B" :init 1}))
+
+;; ── combined ──────────────────────────────────────────────────────
+
+(cl-test
+  "combined: full lambda list"
+  (let
+    ((parsed (ll "(x y &optional (z 0 z-p) &rest args &key a (b nil b-p) &aux temp)")))
+    (list
+      (get parsed "required")
+      (get (nth (get parsed "optional") 0) "name")
+      (get (nth (get parsed "optional") 0) "default")
+      (get (nth (get parsed "optional") 0) "supplied")
+      (get parsed "rest")
+      (get (nth (get parsed "key") 0) "name")
+      (get (nth (get parsed "key") 1) "supplied")
+      (get (nth (get parsed "aux") 0) "name")))
+  (list
+    (list "X" "Y")
+    "Z"
+    0
+    "Z-P"
+    "ARGS"
+    "A"
+    "B-P"
+    "TEMP"))
+
+(cl-test
+  "combined: required only stops before &"
+  (ll-req "(a b &optional c)")
+  (list "A" "B"))
+
+(cl-test
+  "combined: required only with &key"
+  (ll-req "(x &key y)")
+  (list "X"))
+
+(cl-test
+  "combined: &rest and &key together"
+  (let
+    ((parsed (ll "(&rest args &key verbose)")))
+    (list (get parsed "rest") (get (nth (get parsed "key") 0) "name")))
+  (list "ARGS" "VERBOSE"))
diff --git a/plans/common-lisp-on-sx.md b/plans/common-lisp-on-sx.md
index d8c4aa67..c468f708 100644
--- a/plans/common-lisp-on-sx.md
+++ b/plans/common-lisp-on-sx.md
@@ -52,8 +52,8 @@ Core mapping:
 ### Phase 1 — reader + parser
 - [x] Tokenizer: symbols (with package qualification `pkg:sym` / `pkg::sym`), numbers (int, float, ratio `1/3`, `#xFF`, `#b1010`, `#o17`), strings `"…"` with `\` escapes, characters `#\Space` `#\Newline` `#\a`, comments `;`, block comments `#| … |#`
 - [x] Reader: list, dotted pair, quote `'`, function `#'`, quasiquote `` ` ``, unquote `,`, splice `,@`, vector `#(…)`, uninterned `#:foo`, nil/t literals
-- [ ] Parser: lambda lists with `&optional` `&rest` `&key` `&aux` `&allow-other-keys`, defaults, supplied-p variables
-- [ ] Unit tests in `lib/common-lisp/tests/read.sx`
+- [x] Parser: lambda lists with `&optional` `&rest` `&key` `&aux` `&allow-other-keys`, defaults, supplied-p variables
+- [x] Unit tests in `lib/common-lisp/tests/read.sx`
 
 ### Phase 2 — sequential eval + special forms
 - [ ] `cl-eval-ast`: `quote`, `if`, `progn`, `let`, `let*`, `flet`, `labels`, `setq`, `setf` (subset), `function`, `lambda`, `the`, `locally`, `eval-when`
@@ -114,6 +114,7 @@ Core mapping:
 
 _Newest first._
 
+- 2026-04-25: Phase 1 lambda-list parser — 31 new tests, 172 total green. `cl-parse-lambda-list` in `parser.sx` + `tests/lambda.sx`. Handles &optional/&rest/&body/&key/&aux/&allow-other-keys, defaults, supplied-p. Key gotchas: `(when (> (len items) 0) ...)` not `(when items ...)` (empty list is truthy); custom `cl-deep=` needed for dict/list structural equality in tests.
 - 2026-04-25: Phase 1 reader/parser — 62 new tests, 141 total green. `lib/common-lisp/parser.sx`: cl-read/cl-read-all, lists, dotted pairs, quote/backquote/unquote/splice/#', vectors, #:uninterned, NIL→nil, T→true, reader macro wrappers.
 - 2026-04-25: Phase 1 tokenizer — 79 tests green. `lib/common-lisp/reader.sx` + `tests/read.sx` + `test.sh`. Handles symbols (pkg:sym, pkg::sym), integers, floats, ratios, hex/binary/octal, strings, #\ chars, reader macros (#' #( #: ,@), line/block comments. Key gotcha: SX `str` for string concat (not `concat`), substring-based read-while.