import nesting for gerbil

group-in.ss

(import (for-syntax :std/misc/list))
(export group-in)
(defsyntax-for-import (group-in stx)
  (def (expand-path top mod)
    (syntax-case mod ()
      ((nested mod ...)
       (map (lambda (mod) (stx-identifier top top "/" mod))
            (flatten (map (cut expand-path #'nested <>) #'(mod ...)))))
      (id
       (identifier? #'id)
       (stx-identifier top top "/" #'id))))

  (syntax-case stx ()
    ((_ top mod ...)
     (cons begin: (flatten (map (cut expand-path #'top <>) #'(mod ...)))))))