!275 Improve rich-vector%make-string in (liii lang)

GoldfishLang.tmu

@@ -2576,13 +2576,13 @@
   <\goldfish-chunk|goldfish/liii/lang.scm|true|true>
     (chained-define (%map f)
 
-    \ \ (rich-string
+    \ \ ((%to-vector)
 
-    \ \ \ \ (%to-vector :map f
+    \ \ \ :map f
 
-    \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ :map (lambda (c) (rich-string :value-of c))
+    \ \ \ :map (@ _ :make-string)
 
-    \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ :make-string)))
+    \ \ \ :make-string))
 
     \;
   </goldfish-chunk>
@@ -2635,12 +2635,10 @@
     \;
   </goldfish-chunk>
 
-  \;
-
   <paragraph|rich-string%to-vector>
 
   <\goldfish-chunk|goldfish/liii/lang.scm|true|true>
-    (chained-define (%to-vector)
+    (define (%to-vector)
 
     \ \ (if (string-null? data)
 
@@ -5340,7 +5338,7 @@
 
     \ \ \ \ \ \ \ \ \ \ \ (middle (string-join (map as-string (vector-\<gtr\>list data)) sep)))
 
-    \ \ \ \ \ \ (string-append start middle end))))
+    \ \ \ \ \ \ (rich-string (string-append start middle end)))))
 
     \;
   </scm-chunk>

goldfish/liii/lang.scm

@@ -474,18 +474,18 @@
        (else (loop (cdr lst) (+ index 1)))))))))
 
 (chained-define (%map f)
-  (rich-string
-    (%to-vector :map f
-                :map (lambda (c) (rich-string :value-of c))
-                :make-string)))
+  ((%to-vector)
+   :map f
+   :map (@ _ :make-string)
+   :make-string))
 
 (define (%count pred?)
   ((%to-vector) :count pred?))
 
 (define (%to-string)
   data)
 
-(chained-define (%to-vector)
+(define (%to-vector)
   (if (string-null? data)
       (rich-vector :empty)
       (let* ((bv (string->utf8 data))
@@ -1092,7 +1092,7 @@
   (receive (start sep end) (parse-args xs)
     (let* ((as-string (lambda (x) (if (string? x) x (object->string x))))
            (middle (string-join (map as-string (vector->list data)) sep)))
-      (string-append start middle end))))
+      (rich-string (string-append start middle end)))))
 
 (define (%set! i x)
   (when (or (< i 0) (>= i (length data)))