haskell: Phase 8 audit — hk-show-val matches Haskell 98 (precedence-based parens, no-space separators)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

lib/haskell/eval.sx

@@ -584,13 +584,14 @@
         result))))
 
 (define
-  hk-show-val
+  hk-show-prec
   (fn
-    (v)
+    (v p)
     (let
       ((fv (hk-force v)))
       (cond
-        ((= (type-of fv) "number") (str fv))
+        ((= (type-of fv) "number")
+          (if (and (< fv 0) (>= p 11)) (str "(" fv ")") (str fv)))
         ((= (type-of fv) "string") (str "\"" fv "\""))
         ((= (type-of fv) "boolean") (if fv "True" "False"))
         ((not (list? fv)) (str fv))
@@ -599,9 +600,15 @@
         ((= (first fv) ":")
           (let
             ((elems (hk-collect-hk-list fv)))
-            (str "[" (hk-join-strs (map hk-show-val elems) ", ") "]")))
+            (str
+              "["
+              (hk-join-strs (map (fn (e) (hk-show-prec e 0)) elems) ",")
+              "]")))
         ((= (first fv) "Tuple")
-          (str "(" (hk-join-strs (map hk-show-val (rest fv)) ", ") ")"))
+          (str
+            "("
+            (hk-join-strs (map (fn (e) (hk-show-prec e 0)) (rest fv)) ",")
+            ")"))
         ((= (first fv) "()") "()")
         (:else
           (let
@@ -609,14 +616,15 @@
             (if
               (empty? args)
               cname
-              (str
-                "("
-                cname
-                " "
-                (hk-join-strs (map hk-show-val args) " ")
-                ")"))))))))
+              (let
+                ((s (str cname " " (hk-join-strs (map (fn (a) (hk-show-prec a 11)) args) " "))))
+                (if (>= p 11) (str "(" s ")") s)))))))))
 
 ;; ── Source-level convenience ────────────────────────────────
+(define hk-show-val (fn (v) (hk-show-prec v 0)))
+
+;; Eagerly build the Prelude env once at load time; each call to
+;; hk-eval-expr-source copies it instead of re-parsing the whole Prelude.
 (define
   hk-init-env
   (fn
@@ -997,8 +1005,6 @@
               1))
           env)))))
 
-;; Eagerly build the Prelude env once at load time; each call to
-;; hk-eval-expr-source copies it instead of re-parsing the whole Prelude.
 (define
   hk-bind-decls!
   (fn