In SGF Utils[0], i use ‘shunt’:

 (define-macro (shunt proc-names . otherwise)
   `(lambda (command . args)
      (apply (case command
               ,@(map (lambda (name)
                        `((,name) ,name))
                      proc-names)
               (else
                ,(if (null? otherwise)
                     '(error "bad command:" command)
                     `(lambda args
                        ,(car otherwise)))))
             args)))

to delegate commands to a closure's set of internal procedures.
Is something similar already included w/ Guile?

___________________________
[0] http://www.gnuvola.org/software/sgf-utils/

    $ cd .../sgf-utils/src && grep -nHF -e shunt  *.scm
    base.scm:27:  #:export (catch-one FE shunt fs fop<-))
    base.scm:41:(define-macro (shunt proc-names . otherwise)
    base.scm:42:  ;; (put 'shunt 'scheme-indent-function 1)
    gnugo.scm:54: ((base) #:select (shunt fs))
    gnugo.scm:173:    (shunt (set-board-size!
    render.scm:27: ((base) #:select (FE fs shunt))
    render.scm:106:    (shunt (h1)
    render.scm:209:    (shunt (try))))
    render.scm:910:    (define I (shunt (clear!
    sgfv.scm:85: ((base) #:select (FE shunt fs fop<-))
    sgfv.scm:312:    (shunt (at forw! back! vary!

-- 
Thien-Thi Nguyen -----------------------------------------------
 (defun responsep (query)
   (pcase (context query)
     (`(technical ,ml) (correctp ml))
     ...))                              748E A0E8 1CB8 A748 9BFA
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