pcs/edwin/io.scm

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;;;
;;; Copyright (c) 1985 Massachusetts Institute of Technology
;;;
;;; This material was developed by the Scheme project at the
;;; Massachusetts Institute of Technology, Department of
;;; Electrical Engineering and Computer Science. Permission to
;;; copy this software, to redistribute it, and to use it for any
;;; purpose is granted, subject to the following restrictions and
;;; understandings.
;;;
;;; 1. Any copy made of this software must include this copyright
;;; notice in full.
;;;
;;; 2. Users of this software agree to make their best efforts (a)
;;; to return to the MIT Scheme project any improvements or
;;; extensions that they make, so that these may be included in
;;; future releases; and (b) to inform MIT of noteworthy uses of
;;; this software.
;;;
;;; 3. All materials developed as a consequence of the use of
;;; this software shall duly acknowledge such use, in accordance
;;; with the usual standards of acknowledging credit in academic
;;; research.
;;;
;;; 4. MIT has made no warrantee or representation that the
;;; operation of this software will be error-free, and MIT is
;;; under no obligation to provide any services, by way of
;;; maintenance, update, or otherwise.
;;;
;;; 5. In conjunction with products arising from the use of this
;;; material, there shall be no use of the name of the
;;; Massachusetts Institute of Technology nor of any adaptation
;;; thereof in any advertising, promotional, or sales literature
;;; without prior written consent from MIT in each case.
;;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;;
;;; Modified by Texas Instruments Inc 8/15/85
;;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;; File IO
(define read-buffer
(lambda (buffer filename)
(region-delete! (buffer-region buffer))
(if (file-exists? filename)
(begin
(let ((region (file->region-interactive filename)))
(vector-set! (current-window) window:point
(mark-right-inserting (buffer-start buffer)))
(region-insert! (buffer-start buffer) region))
(set-current-point! (buffer-start buffer)))
(temporary-message "(New File)"))
(set-buffer-truename! buffer filename)
(set-buffer-pathname! buffer filename)
(buffer-not-modified! buffer)))
(define insert-file
(lambda (mark filename)
(if (file-exists? filename)
(region-insert! mark (file->region-interactive filename))
(editor-error (string-append "File " filename " not found")))))
(define file->region-interactive
(lambda (filename)
(temporary-message (string-append "Reading file " filename))
(let ((region (file->region filename)))
(append-message " -- done")
region)))
(define file->region
(lambda (filename)
(let ((port '()))
(dynamic-wind
(lambda () (set! port (open-input-file filename)))
(lambda () (file-stream->region port))
(lambda () (close-input-port port))))))
(define (file-stream->region stream)
(let ((first-line (read-line stream)))
(if (not (eof-object? first-line))
(let ((first-line (make-line first-line))
(group (make-group #!FALSE)))
(define (%connect-lines previous-line this-line n)
(connect-lines! previous-line this-line)
(set-line-group! this-line group)
(set-line-number! this-line n))
(define (loop previous-line n this-line)
(if (not (eof-object? this-line))
(let ((this-line (make-line this-line)))
(%connect-lines previous-line this-line n)
(loop this-line (+ n line-number-increment)
(read-line stream)))
(let ((this-line (make-line "")))
(%connect-lines previous-line this-line n)
(let ((region
(components->region first-line 0 this-line
(line-length this-line))))
(%set-group-region! group region)
region))))
(set-line-group! first-line group)
(set-line-number! first-line 0)
(loop first-line line-number-increment (read-line stream)))
(let ((line (make-line "")))
(lines->region line line)))))
;;;; Output
(define write-buffer
(lambda (buffer filename)
(if (or (not (file-exists? filename))
(prompt-for-confirmation?
(string-append "File " filename
" exists. Write anyway (Y or N)?")))
(begin
(temporary-message (string-append "Writing file " filename))
(region->file (buffer-region buffer) filename)
(append-message " -- done")
(set-buffer-pathname! buffer filename)
(set-buffer-truename! buffer filename)
(buffer-not-modified! buffer)))))
(define write-region
(lambda (region filename)
(if (or (not (file-exists? filename))
(prompt-for-confirmation?
(string-append "File " filename
" exists. Write anyway (Y or N)?")))
(begin
(temporary-message (string-append "Writing file " filename))
(region->file region filename)
(append-message " -- done")))))
(define (region->file region filename)
(let ((port '()))
(dynamic-wind
(lambda () (set! port (open-output-file filename)))
(lambda () (region->filestream region port))
(lambda () (close-output-port port)))))
(define (region->filestream region stream)
(region-components region
(lambda (start-line start-position end-line end-position)
(if (eq? start-line end-line)
(princ (substring (line-string start-line)
start-position
end-position)
stream)
(begin
(princ (substring (line-string start-line)
start-position
(line-length start-line))
stream)
(let loop ((this-line (line-next start-line)))
(princ #\newline stream)
(if (eq? this-line end-line)
(princ (substring (line-string end-line)
0
end-position)
stream)
(begin (princ (line-string this-line) stream)
(loop (line-next this-line))))))))))
(define (save-buffer-changes buffer)
(if (and (buffer-pathname buffer)
(buffer-modified? buffer)
(buffer-writeable? buffer)
(prompt-for-confirmation?
(string-append "Buffer "
(buffer-name buffer)
" contains changes. Write them out (Y or N)?")))
(write-buffer buffer (buffer-pathname buffer))))
(define (%save-buffer-changes buffer)
(if (and (buffer-modified? buffer)
(buffer-writeable? buffer)
(prompt-for-confirmation?
(string-append "Buffer "
(buffer-name buffer)
" contains changes. Write them out (Y or N)?")))
(save-file buffer)))
(define (setup-current-buffer-read-only! argument)
((cond ((or (not argument) (zero? argument)) set-buffer-writeable!)
((negative? argument) set-buffer-read-only!)
(else set-buffer-file-read-only!))
(current-buffer)))
(define (save-file buffer)
(if (buffer-modified? buffer)
(if (or (buffer-writeable? buffer)
(prompt-for-confirmation?
(string-append "Buffer " (buffer-name buffer)
" is read only. Save anyway (Y or N)?")))
(write-buffer buffer
(let ((pathname (buffer-pathname buffer)))
(if (not pathname)
(prompt-for-pathname
"Write buffer to file : ")
pathname))))
(temporary-message "(No changes need to be written)")))