go: parse.sx — unary prefix operators + 11 tests [nothing]

Adds Go unary prefix operators per Go spec § Operators:
  +x  -x  !x  ^x  *p  &v  <-ch

gp-parse-unary is recursive (so !!x and -^x chain correctly) and
sits between gp-parse-expr and gp-parse-primary — unary therefore
always binds tighter than any binary op without needing a unary
entry in the precedence table.

Symbols +, -, *, &, ^ are shared between unary and binary forms;
the positional split (expression-start sees unary, mid-expression
sees binary) disambiguates them cleanly with no lookback.

Unary nodes are single-arg ast-app:
  (ast-app (ast-var OP) (list OPERAND))

parse 37/37, total 166/166.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

lib/go/parse.sx

@@ -64,11 +64,32 @@
               (= ty "ident")
               (do (gp-advance!) (ast-var v))
               :else nil))))
+      (define
+        gp-unary-ops
+        ;; Go spec § Operators: prefix unary, all higher precedence than
+        ;; any binary operator. <- is the channel receive form (send is a
+        ;; statement, not an expression, so never appears here as binary).
+        (list "+" "-" "!" "^" "*" "&" "<-"))
+      (define
+        gp-parse-unary
+        (fn
+          ()
+          (let ((tok (gp-cur)))
+            (cond
+              (and (= (get tok :type) "op")
+                   (some (fn (u) (= u (get tok :value))) gp-unary-ops))
+              (do
+                (gp-advance!)
+                (let ((operand (gp-parse-unary)))
+                  (cond
+                    (= operand nil) nil
+                    :else (ast-app (ast-var (get tok :value)) (list operand)))))
+              :else (gp-parse-primary)))))
       (define
         gp-parse-expr
         (fn
           (min-prec)
-          (let ((left (gp-parse-primary))) (gp-pratt-loop left min-prec))))
+          (let ((left (gp-parse-unary))) (gp-pratt-loop left min-prec))))
       (define
         gp-pratt-loop
         (fn

lib/go/scoreboard.json

@@ -1,10 +1,10 @@
 {
   "language": "go",
-  "total_pass": 155,
+  "total_pass": 166,
-  "total": 155,
+  "total": 166,
   "suites": [
     {"name":"lex","pass":129,"total":129,"status":"ok"},
-    {"name":"parse","pass":26,"total":26,"status":"ok"},
+    {"name":"parse","pass":37,"total":37,"status":"ok"},
     {"name":"types","pass":0,"total":0,"status":"pending"},
     {"name":"eval","pass":0,"total":0,"status":"pending"},
     {"name":"runtime","pass":0,"total":0,"status":"pending"},

lib/go/scoreboard.md

@@ -1,11 +1,11 @@
 # Go-on-SX Scoreboard
 
-**Total: 155 / 155 tests passing**
+**Total: 166 / 166 tests passing**
 
 |  | Suite | Pass | Total |
 |---|---|---|---|
 | ✅ | lex | 129 | 129 |
-| ✅ | parse | 26 | 26 |
+| ✅ | parse | 37 | 37 |
 | ⬜ | types | 0 | 0 |
 | ⬜ | eval | 0 | 0 |
 | ⬜ | runtime | 0 | 0 |

lib/go/tests/parse.sx

@@ -111,6 +111,67 @@
       (ast-app (ast-var "|") (list (ast-var "a") (ast-var "b")))
       (ast-var "c"))))
 
+(go-parse-test
+  "unary: -a"
+  (go-parse "-a")
+  (ast-app (ast-var "-") (list (ast-var "a"))))
+
+(go-parse-test
+  "unary: +a"
+  (go-parse "+a")
+  (ast-app (ast-var "+") (list (ast-var "a"))))
+
+(go-parse-test
+  "unary: !x"
+  (go-parse "!x")
+  (ast-app (ast-var "!") (list (ast-var "x"))))
+
+(go-parse-test
+  "unary: ^x (bitwise NOT)"
+  (go-parse "^x")
+  (ast-app (ast-var "^") (list (ast-var "x"))))
+
+(go-parse-test
+  "unary: *p (pointer deref)"
+  (go-parse "*p")
+  (ast-app (ast-var "*") (list (ast-var "p"))))
+
+(go-parse-test
+  "unary: &v (address-of)"
+  (go-parse "&v")
+  (ast-app (ast-var "&") (list (ast-var "v"))))
+
+(go-parse-test
+  "unary: <-ch (channel recv)"
+  (go-parse "<-ch")
+  (ast-app (ast-var "<-") (list (ast-var "ch"))))
+
+(go-parse-test
+  "unary: -1 (on literal)"
+  (go-parse "-1")
+  (ast-app (ast-var "-") (list (ast-literal "1"))))
+
+(go-parse-test
+  "unary: !!x (chained, right-recursive)"
+  (go-parse "!!x")
+  (ast-app
+    (ast-var "!")
+    (list (ast-app (ast-var "!") (list (ast-var "x"))))))
+
+(go-parse-test
+  "unary: -a + b → ((-a) + b) — unary tighter than binary"
+  (go-parse "-a + b")
+  (ast-app
+    (ast-var "+")
+    (list (ast-app (ast-var "-") (list (ast-var "a"))) (ast-var "b"))))
+
+(go-parse-test
+  "unary: a + -b → unary applies to RHS"
+  (go-parse "a + -b")
+  (ast-app
+    (ast-var "+")
+    (list (ast-var "a") (ast-app (ast-var "-") (list (ast-var "b"))))))
+
 (go-parse-test "non-primary: '+'" (go-parse "+") nil)
 
 (go-parse-test "non-primary: empty" (go-parse "") nil)

plans/go-on-sx.md

@@ -160,7 +160,9 @@ Progress-log line → push `origin/loops/go`.
 - [x] Binary operators (Pratt precedence climbing using `pratt-op-lookup`
       + Go precedence table). Operator app emitted as
       `(ast-app (ast-var OP) [LHS RHS])`; left-assoc raises right-min by 1.
-- [ ] Unary operators (`!x`, `-x`, `^x`, `*p`, `&v`, `<-ch`).
+- [x] Unary operators (`+x`, `-x`, `!x`, `^x`, `*p`, `&v`, `<-ch`).
+      `gp-parse-unary` recursive, sits between `gp-parse-expr` and
+      `gp-parse-primary`; right-associative chains (`!!x`).
 - [ ] Function calls `f(a, b)` and member access `x.field`.
 - [ ] Index `x[i]` and slice `x[a:b]`/`x[a:b:c]`.
 - [ ] Type assertion `v.(T)`.
@@ -176,7 +178,7 @@ Progress-log line → push `origin/loops/go`.
       assign, short-decl `:=`, send `ch <- v`, recv `<-ch`.
 - [ ] End-to-end: hello-world, fibonacci, FizzBuzz, goroutine ping-pong,
       struct + method.
-- **Acceptance:** parse/ suite at 80+ tests. Current: 26/26.
+- **Acceptance:** parse/ suite at 80+ tests. Current: 37/37.
 
 ### Phase 3 — Bidirectional type checker, MVP (`lib/go/types.sx`) ⬜
 - **Independent implementation.** Do NOT use lib/guest/static-types-
@@ -435,6 +437,13 @@ Minimal repro: see `lib/go/lex.sx#gl-oct-digit?` and `#gl-match-op`.
 
 _Newest first. Append one dated entry per commit._
 
+- 2026-05-27 — Phase 2 cont.: unary prefix operators (`+`, `-`, `!`, `^`,
+  `*`, `&`, `<-`). `gp-parse-unary` is recursive (`!!x`) and sits between
+  `gp-parse-expr` and `gp-parse-primary` so unary always binds tighter
+  than any binary. Symbols `+ - * & ^` are shared with binary; the
+  positional split (expression-start vs mid-expression) disambiguates
+  cleanly without lookback. Unary nodes are single-arg `ast-app`. +11
+  tests, parse 37/37, total 166/166. `[nothing]` — pure Go parser work.
 - 2026-05-27 — Phase 2 cont.: binary operators via Pratt precedence
   climbing. `gp-pratt-loop` consumes `pratt-op-lookup` against
   `go-precedence-table`; left-assoc bumps right-min by 1, right-assoc