;;;
;;; gauche.experimental.shared-struct
;;;
;;;   Copyright (c) 2021-2022  Shiro Kawai  <shiro@acm.org>
;;;
;;;   Redistribution and use in source and binary forms, with or without
;;;   modification, are permitted provided that the following conditions
;;;   are met:
;;;
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;;;      notice, this list of conditions and the following disclaimer.
;;;
;;;   2. Redistributions in binary form must reproduce the above copyright
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;;;      documentation and/or other materials provided with the distribution.
;;;
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;;;      software without specific prior written permission.
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;;;

;; This treats shared-box as a struct.

(define-module gauche.experimental.shared-struct
  (use util.match)
  (use gauche.sequence)
  (use gauche.experimental.shared-box)
  (export define-shared-struct))
(select-module gauche.experimental.shared-struct)

(define-syntax define-shared-struct
  (er-macro-transformer
   (^[f r c]
     (match f
       [(_ name init-count slots ...)
        (define (make-accessor i slot)
          (quasirename r
            `(define-inline (,(symbol-append name '- slot) b)
               (unbox-value b ,i))))
        (define (make-mutator i slot)
          (quasirename r
            `(define-inline (,(symbol-append name '- slot '-set!) b v)
               (set-box-value! b ,i v))))

        (quasirename r
          `(begin
             (define-inline (,(symbol-append 'make- name) ,@slots)
               (shared-box ,init-count ,@slots))
             ,@(map-with-index make-accessor slots)
             ,@(map-with-index make-mutator slots)
             ',name))]))))
