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

125 lines
4.1 KiB
Scheme

;;; Ikarus Scheme -- A compiler for R6RS Scheme.
;;; Copyright (C) 2006,2007 Abdulaziz Ghuloum
;;;
;;; This program is free software: you can redistribute it and/or modify
;;; it under the terms of the GNU General Public License version 3 as
;;; published by the Free Software Foundation.
;;;
;;; This program 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 this program. If not, see <http://www.gnu.org/licenses/>.
(library (ikarus io-primitives unsafe)
(export $write-char $write-byte $read-char $get-u8 $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 $chars)
(ikarus system $bytevectors)
(ikarus system $fx))
(define $write-char
(lambda (c p)
(let ([b ($char->fixnum c)])
(cond
[($fx<= b #x7F)
($write-byte b p)]
[($fx<= b #x7FF)
($write-byte
($fxlogor #b11000000 ($fxsra b 6)) p)
($write-byte
($fxlogor #b10000000 ($fxlogand b #b111111)) p)]
[($fx<= b #xFFFF)
($write-byte
($fxlogor #b11100000 ($fxsra b 12)) p)
($write-byte
($fxlogor #b10000000 ($fxlogand ($fxsra b 6) #b111111)) p)
($write-byte
($fxlogor #b10000000 ($fxlogand b #b111111)) p)]
[else
($write-byte
($fxlogor #b11110000 ($fxsra b 18)) p)
($write-byte
($fxlogor #b10000000 ($fxlogand ($fxsra b 12) #b111111)) p)
($write-byte
($fxlogor #b10000000 ($fxlogand ($fxsra b 6) #b111111)) p)
($write-byte
($fxlogor #b10000000 ($fxlogand b #b111111)) p)]))))
(define $write-byte
(lambda (b p)
(let ([idx (port-output-index p)])
(if ($fx< idx ($port-size p))
(begin
($bytevector-set! ($port-buffer p) idx b)
($set-port-index! p ($fxadd1 idx)))
(($port-handler p) 'write-byte b p)))))
(define $read-char
(lambda (p)
(let ([idx ($port-index p)])
(if ($fx< idx ($port-size p))
(let ([b ($bytevector-u8-ref ($port-buffer p) idx)])
(cond
[($fx<= b 127)
($set-port-index! p ($fxadd1 idx))
($fixnum->char b)]
[else (($port-handler p) 'read-char p)]))
(($port-handler p) 'read-char p)))))
(define $get-u8
(lambda (p)
(let ([idx ($port-index p)])
(if ($fx< idx ($port-size p))
(let ([b ($bytevector-u8-ref ($port-buffer p) idx)])
($set-port-index! p ($fxadd1 idx))
b)
(($port-handler p) 'get-u8 p)))))
(define $peek-char
(lambda (p)
(let ([idx ($port-index p)])
(if ($fx< idx ($port-size p))
(let ([b ($bytevector-u8-ref ($port-buffer p) idx)])
(cond
[($fx<= b 127)
($fixnum->char b)]
[else (($port-handler p) 'peek-char p)]))
(($port-handler p) 'peek-char p)))))
(define $unread-char
(lambda (c p)
(let ([idx ($fxsub1 ($port-index p))]
[b ($char->fixnum c)])
(if (and ($fx<= b 127)
($fx>= idx 0)
($fx< idx ($port-size p)))
(begin
($set-port-index! p idx)
($bytevector-set! ($port-buffer p) idx b))
(($port-handler p) 'unread-char c p)))))
(define $reset-input-port!
(lambda (p)
($set-port-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))))