ikarus/src/ikarus.io-primitives.unsafe.ss

63 lines
1.8 KiB
Scheme

(library (ikarus io-primitives unsafe)
(export $write-char $read-char $unread-char $peek-char
$reset-input-port! $flush-output-port
$close-input-port $close-output-port)
(import
(ikarus)
(ikarus system $ports)
(ikarus system $strings)
(ikarus system $fx))
(define $write-char
(lambda (c p)
(let ([idx (port-output-index p)])
(if ($fx< idx ($port-output-size p))
(begin
($string-set! ($port-output-buffer p) idx c)
($set-port-output-index! p ($fxadd1 idx)))
(($port-handler p) 'write-char c p)))))
(define $read-char
(lambda (p)
(let ([idx ($port-input-index p)])
(if ($fx< idx ($port-input-size p))
(begin
($set-port-input-index! p ($fxadd1 idx))
($string-ref ($port-input-buffer p) idx))
(begin
(($port-handler p) 'read-char p))))))
(define $peek-char
(lambda (p)
(let ([idx ($port-input-index p)])
(if ($fx< idx ($port-input-size p))
($string-ref ($port-input-buffer p) idx)
(($port-handler p) 'peek-char p)))))
(define $unread-char
(lambda (c p)
(let ([idx ($fxsub1 ($port-input-index p))])
(if (and ($fx>= idx 0)
($fx< idx ($port-input-size p)))
(begin
($set-port-input-index! p idx)
($string-set! ($port-input-buffer p) idx c))
(($port-handler p) 'unread-char c p)))))
(define $reset-input-port!
(lambda (p)
($set-port-input-size! p 0)))
(define $close-input-port
(lambda (p)
(($port-handler p) 'close-port p)))
(define $close-output-port
(lambda (p)
(($port-handler p) 'close-port p)))
(define $flush-output-port
(lambda (p)
(($port-handler p) 'flush-output-port p))))