Write a macro which defines a procedure

[zelphirkaltstahl]

Hi Guile Users,

I want to write a macro, which creates a procedure of given name, where 
the given name is a not yet defined identifier.
Here is what I have so far:

--------8<--------begin-------->8--------
(use-modules (web uri)
             (web client)
             (json)
             (ice-9 iconv))

(define-syntax define-api-route
  (syntax-rules ()
    [(define-api-route route http-method my-content-type)
     (module-define! (current-module)
                     ;; `route` should be `/container/json` for example.
                     route
                     (lambda* (docker-socket #:key (data #f))
                       (call-with-values
                           (lambda ()
                             ;; Here the route needs to be given as a 
string to `http-get`.
                             (http-get (variable-name->string route)
                                       #:port docker-socket
                                       #:version '(1 . 1)
                                       #:keep-alive? #f
                                       ;; Why is my quasiquote not 
working as expected?
                                       #:headers `((host . ("localhost" 
. #f))
                                                   (content-type . 
(,my-content-type (charset . "utf-8"))))
                                       #:body (scm->json-string data)
                                       #:decode-body? #t
                                       #:streaming? #f))
                         (lambda (response response-text)
                           (let ([resp-text-as-string 
(bytevector->string response-text "utf-8")])
                             (cons response resp-text-as-string))))))]))

;; from: https://stackoverflow.com/a/21177216/1829329
(define-syntax variable-name->string
  (lambda (stx)
    (syntax-case stx ()
      ((_ id)
       (identifier? #'id)
       (datum->syntax #'id (symbol->string (syntax->datum #'id)))))))
--------8<--------end-------->8--------

However, when I call this macro as follows:


--------8<--------begin-------->8--------
(define-api-route /container/json 'POST 
application/x-www-form-urlencoded)
--------8<--------end-------->8--------

I get the following error:

--------8<--------begin-------->8--------
;;; <stdin>:33:0: warning: possibly unbound variable `/container/json'
;;; <stdin>:33:0: warning: possibly unbound variable 
`application/x-www-form-urlencoded'
<unnamed port>:33:0: In procedure module-lookup: Unbound variable: 
/container/json
--------8<--------end-------->8--------

So I see that there are at least 2 problems with my macro:

1. `/container/json` is not defined. I thought it would be defined, as I 
tried to make the macro define it in the current module.
2. `application/x-www-form-urlencoded` is evaluated, although I have it 
in a quasiquoted expression.

There are other things, which I would like to implement once I get the 
above working:

* I would like the macro to complain, if there is other stuff with the 
same identifier already defined inside the module, as a little safety 
measure. However, this might be difficult, I guess, because the macro 
might be done before those other definitions of same identifier are even 
executed.

Anyway, can you help me out writing the macro, fixing at least the 2 
issues or direct me to a tutorial, which covers how to write a macro 
which gives basically a new define form?

Regards,
Zelphir