Fcalva/chibi-scheme
1
0
Fork 0
mirror of https://github.com/ashinn/chibi-scheme.git synced 2025-07-12 15:37:35 +02:00
Code Issues Projects Releases Packages Wiki Activity Actions

Defining with-in/output-from/to-file in terms of dynamic-wind.

Browse source
This commit is contained in:
Alex Shinn 2011-12-20 00:58:27 +09:00
parent 8eb74156f9
commit 87970984c7
1 changed files with 16 additions and 16 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

32
lib/init-7.scm
View file

@ -514,22 +514,6 @@
(close-output-port out) (close-output-port out)
res)) res))
(define (with-input-from-file file thunk)
(let ((old-in (current-input-port))
(tmp-in (open-input-file file)))
(current-input-port tmp-in)
(let ((res (thunk)))
(current-input-port old-in)
res)))
(define (with-output-to-file file thunk)
(let ((old-out (current-output-port))
(tmp-out (open-output-file file)))
(current-output-port tmp-out)
(let ((res (thunk)))
(current-output-port old-out)
res)))
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; values ;; values
@ -603,6 +587,22 @@
(let ((dk (%dk))) (let ((dk (%dk)))
(%call/cc (lambda (k) (proc (lambda x (set-dk! dk) (k (%values x)))))))) (%call/cc (lambda (k) (proc (lambda x (set-dk! dk) (k (%values x))))))))
(define (with-input-from-file file thunk)
(let ((old-in (current-input-port))
(tmp-in (open-input-file file)))
(dynamic-wind
(lambda () (current-input-port tmp-in))
thunk
(lambda () (current-input-port old-in)))))
(define (with-output-to-file file thunk)
(let ((old-out (current-output-port))
(tmp-out (open-output-file file)))
(dynamic-wind
(lambda () (current-output-port tmp-out))
thunk
(lambda () (current-output-port old-out)))))
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; syntax-rules ;; syntax-rules