Idea for amazon-s3 api improvement

gistfile1.scm

(define (put-options #!key canned-acl metadata content-type expires storage-class)
  (when (and canned-acl
             (not (member canned-acl '(private full-control public read authenticated-read))))
        (error "invalid canned-acl specified"))
  (filter (cut cdr <>)
          `((canned-acl . ,canned-acl) (metadata . ,metadata) (content-type . ,content-type)
            (expires . ,expires) (storage-class . ,storage-class))))

(define (put-object! bucket key object-thunk object-length object-type . options)
  (perform-aws-request bucket: bucket path: key verb: "PUT" content-type: object-type body: object-thunk
                       content-length: object-length no-xml: #t
                       options: (if (null? options) '() (car options))))


; example
(let ((opts (put-options canned-acl: 'private)))
  (put-object! "bucket" "key" thunk 10 "foo" opts)
  (put-string! "bucket" "key" "value" opts))

; making your own options
(put-string! "bucket" "key" "value" '((canned-acl . 'private) (metainfo . "foo")))