;; Copyright (c) 2009 Derick Eddington
;;
;; Permission is hereby granted, free of charge, to any person obtaining a
;; copy of this software and associated documentation files (the "Software"),
;; to deal in the Software without restriction, including without limitation
;; the rights to use, copy, modify, merge, publish, distribute, sublicense,
;; and/or sell copies of the Software, and to permit persons to whom the
;; Software is furnished to do so, subject to the following conditions:
;;
;; The above copyright notice and this permission notice shall be included in
;; all copies or substantial portions of the Software.
;;
;; Except as contained in this notice, the name(s) of the above copyright
;; holders shall not be used in advertising or otherwise to promote the sale,
;; use or other dealings in this Software without prior written authorization.
;;
;; THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
;; IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
;; FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
;; THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
;; LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
;; FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
;; DEALINGS IN THE SOFTWARE.

#!r6rs
(library (srfi :61 cond)
  (export
    (rename (general-cond cond)))
  (import
   (only (rnrs) ... _ define-syntax lambda syntax-case with-syntax syntax map cond => apply let-values and)
    )

  
  (define-syntax general-cond
    (lambda (stx)
      (syntax-case stx ()
        [(_ clauses ...)
         (with-syntax ([(ours ...)
                        (map (lambda (c)
                               (syntax-case c (=>)
                                 [(generator guard => receiver)
                                  #'((let-values ([vals generator])
                                       (and (apply guard vals)
                                            vals))
                                     => (lambda (vals)
                                          (apply receiver vals)))]
                                 [_ c]))
                             #'(clauses ...))])
           #'(cond ours ...))])))
)
