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;;; Ikarus Scheme -- A compiler for R6RS Scheme.
;;; Copyright (C) 2006,2007,2008 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 codecs)
(export latin-1-codec utf-8-codec utf-16-codec native-eol-style
make-transcoder native-transcoder buffer-mode?
transcoder-codec transcoder-eol-style
transcoder-error-handling-mode)
(import
(except (ikarus) latin-1-codec utf-8-codec utf-16-codec
native-eol-style make-transcoder native-transcoder
buffer-mode? transcoder-codec
transcoder-eol-style transcoder-error-handling-mode)
(ikarus system $transcoders))
(define (latin-1-codec) 'latin-1-codec)
(define (utf-8-codec) 'utf-8-codec)
(define (utf-16-codec) 'utf-16-codec)
(define (native-eol-style) 'none)
(define error-handling-mode-alist
'([ignore . #b01]
[raise . #b10]
[replace . #b11]))
(define error-handling-mode-mask #b11)
(define eol-style-alist
'([none . #b00000]
[lf . #b00100]
[cr . #b01000]
[crlf . #b01100]
[nel . #b10000]
[crnel . #b10100]
[ls . #b11000]))
(define eol-style-mask #b11100)
(define codec-alist
'([latin-1-codec . #b0100000]
[utf-8-codec . #b1000000]
[utf-16-codec . #b1100000]))
(define codec-mask #b11100000)
(define (rev-lookup n ls)
(cond
[(null? ls) #f]
[(= (cdar ls) n) (caar ls)]
[else (rev-lookup n (cdr ls))]))
(define (codec->fixnum x who)
(cond
[(assq x codec-alist) => cdr]
[else (die who "not a valid coded" x)]))
(define (eol-style->fixnum x who)
(cond
[(assq x eol-style-alist) => cdr]
[else (die who "not a valid eol-style" x)]))
(define (error-handling-mode->fixnum x who)
(cond
[(assq x error-handling-mode-alist) => cdr]
[else (die who "not a valid error-handling mode" x)]))
(define make-transcoder
(case-lambda
[(codec eol-style handling-mode)
($data->transcoder
(fxior
(error-handling-mode->fixnum handling-mode 'make-transcoder)
(eol-style->fixnum eol-style 'make-transcoder)
(codec->fixnum codec 'make-transcoder)))]
[(codec eol-style)
(make-transcoder codec eol-style 'replace)]
[(codec)
(make-transcoder codec 'none 'replace)]))
(define (native-transcoder)
(make-transcoder 'utf-8-codec 'none 'replace))
(define (transcoder-codec x)
(define who 'transcoder-codec)
(if (transcoder? x)
(let ([tag (fxlogand ($transcoder->data x) codec-mask)])
(or (rev-lookup tag codec-alist)
(die who "transcoder has no codec" x)))
(die who "not a transcoder" x)))
(define (transcoder-eol-style x)
(define who 'transcoder-eol-style)
(if (transcoder? x)
(let ([tag (fxlogand ($transcoder->data x) eol-style-mask)])
(or (rev-lookup tag eol-style-alist)
(die who "transcoder has no eol-style" x)))
(die who "not a transcoder" x)))
(define (transcoder-error-handling-mode x)
(define who 'transcoder-error-handling-mode)
(if (transcoder? x)
(let ([tag (fxlogand ($transcoder->data x) error-handling-mode-mask)])
(or (rev-lookup tag error-handling-mode-alist)
(die who "transcoder has no error-handling mode" x)))
(die who "not a transcoder" x)))
(define (buffer-mode? x)
(and (memq x '(none line block)) #t))
)
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