STML base

(define fold
  (lambda xs
    (if (= (length xs) 2)
        (fold_h (car xs) (car (car (cdr xs))) (cdr (car (cdr xs))))
        (apply fold_h xs))))
(define map-reduce
  (lambda (f b xs)
    (fold b (map f xs))))
(define (key-value->string pair)
  (string-append
   (symbol->string (car pair))
   "=\""
   (car (cdr pair))
   "\" "))
(define-syntax define-tag
  (syntax-rules ()
    ((_ tag)
     (define-syntax tag
       (syntax-rules ()
         (('tag ((KEY value) (... ...)) expr* (... ...))
          (string-append
           "<" (symbol->string 'tag) " "
           (map-reduce key-value->string string-append (list '(KEY value) (... ...)))
           ">\n"
           (string-append expr* (... ...))
           "</" (symbol->string 'tag) ">\n"
           ))
         (('tag expr* (... ...))
          (string-append
           "<" (symbol->string 'tag) ">\n"
           (string-append expr* (... ...))
           "</" (symbol->string 'tag) ">\n")))))))