#| -*-Scheme-*-

Copyright (C) 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994,
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    2017, 2018, 2019, 2020, 2021, 2022 Massachusetts Institute of
    Technology

This file is part of MIT/GNU Scheme.

MIT/GNU Scheme is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or (at
your option) any later version.

MIT/GNU Scheme is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
General Public License for more details.

You should have received a copy of the GNU General Public License
along with MIT/GNU Scheme; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301,
USA.

|#

;;;; Buffer Set Abstraction

(declare (usual-integrations))

(define-structure (bufferset (constructor %make-bufferset))
  buffer-list
  (names #f read-only #t))

(define (make-bufferset initial-buffer)
  (%make-bufferset (list initial-buffer)
		   (let ((names (make-string-table 16 false)))
		     (string-table-put! names
					(buffer-name initial-buffer)
					initial-buffer)
		     names)))

(define (bufferset-select-buffer! bufferset buffer)
  (if (memq buffer (bufferset-buffer-list bufferset))
      (set-bufferset-buffer-list!
       bufferset
       (cons buffer (delq! buffer (bufferset-buffer-list bufferset)))))
  unspecific)

(define (bufferset-bury-buffer! bufferset buffer)
  (if (memq buffer (bufferset-buffer-list bufferset))
      (set-bufferset-buffer-list!
       bufferset
       (append! (delq! buffer (bufferset-buffer-list bufferset))
		(list buffer))))
  unspecific)

(define (bufferset-guarantee-buffer! bufferset buffer)
  (if (not (memq buffer (bufferset-buffer-list bufferset)))
      (begin
	(string-table-put! (bufferset-names bufferset)
			   (buffer-name buffer)
			   buffer)
	(set-bufferset-buffer-list! bufferset
				    (append! (bufferset-buffer-list bufferset)
					     (list buffer)))))
  unspecific)

(define (bufferset-find-buffer bufferset name)
  (string-table-get (bufferset-names bufferset) name))

(define (bufferset-create-buffer bufferset name)
  (if (bufferset-find-buffer bufferset name)
      (error "Attempt to re-create buffer" name))
  (let ((buffer
	 (make-buffer name
		      (ref-variable editor-default-mode)
		      (if within-editor?
			  (buffer-default-directory (current-buffer))
			  (working-directory-pathname)))))
    (string-table-put! (bufferset-names bufferset) name buffer)
    (set-bufferset-buffer-list!
     bufferset
     (append! (bufferset-buffer-list bufferset) (list buffer)))
    buffer))

(define (bufferset-find-or-create-buffer bufferset name)
  (or (bufferset-find-buffer bufferset name)
      (bufferset-create-buffer bufferset name)))

(define (bufferset-kill-buffer! bufferset buffer)
  (if (not (memq buffer (bufferset-buffer-list bufferset)))
      (error "Attempt to kill unknown buffer" buffer))
  (set-bufferset-buffer-list! bufferset
			      (delq! buffer (bufferset-buffer-list bufferset)))
  (string-table-remove! (bufferset-names bufferset) (buffer-name buffer)))

(define (bufferset-rename-buffer bufferset buffer new-name)
  (if (not (memq buffer (bufferset-buffer-list bufferset)))
      (error "Attempt to rename unknown buffer" buffer))
  (if (bufferset-find-buffer bufferset new-name)
      (error "Attempt to rename buffer to existing buffer name" new-name))
  (let ((names (bufferset-names bufferset)))
    (string-table-remove! names (buffer-name buffer))
    (set-buffer-name! buffer new-name)
    (string-table-put! names new-name buffer)))