cpython/Modules/cjkcodecs/_iso2022_jp.c

/*
 * _iso2022_jp.c: the ISO-2022-JP codec (RFC1468)
 *
 * Written by Hye-Shik Chang <perky@FreeBSD.org>
 * $CJKCodecs: _iso2022_jp.c,v 1.7 2003/12/31 05:46:55 perky Exp $
 */

#define ISO2022_DESIGNATIONS \
        CHARSET_ASCII, CHARSET_JISX0201_R, CHARSET_JISX0208, CHARSET_JISX0208_O
#define ISO2022_NO_SHIFT
#define ISO2022_USE_JISX0208EXT

#include "codeccommon.h"
#include "iso2022common.h"
#include "alg_jisx0201.h"

ENCMAP(jisxcommon)
DECMAP(jisx0208)

#define HAVE_ENCODER_INIT
ENCODER_INIT(iso2022_jp)
{
    STATE_CLEARFLAGS(state)
    STATE_SETG0(state, CHARSET_ASCII)
    STATE_SETG1(state, CHARSET_ASCII)
    return 0;
}

#define HAVE_ENCODER_RESET
ENCODER_RESET(iso2022_jp)
{
    if (STATE_GETG0(state) != CHARSET_ASCII) {
        RESERVE_OUTBUF(3)
        WRITE3(ESC, '(', 'B')
        STATE_SETG0(state, CHARSET_ASCII)
        NEXT_OUT(3)
    }
    return 0;
}

/* ISO-2022-JP changes designations instead of shifting-out */

ENCODER(iso2022_jp)
{
    while (inleft > 0) {
        Py_UNICODE  c = IN1;
        DBCHAR      code;

        if (c < 0x80) {
            switch (STATE_GETG0(state)) {
            case CHARSET_ASCII:
                WRITE1((unsigned char)c)
                NEXT(1, 1)
                break;
            case CHARSET_JISX0201_R:
                JISX0201_R_ENCODE(c, code)
                else { /* FALLTHROUGH (yay!) */
            default:
                    WRITE3(ESC, '(', 'B')
                    NEXT_OUT(3)
                    STATE_SETG0(state, CHARSET_ASCII)
                    code = c;
                }
                WRITE1((unsigned char)code)
                NEXT(1, 1)
                break;
            }
            if (c == '\n')
                STATE_CLEARFLAG(state, F_SHIFTED)
        }
        else UCS4INVALID(c)
        else {
            unsigned char    charset;

            charset = STATE_GETG0(state);
            if (charset == CHARSET_JISX0201_R) {
                code = DBCINV;
                JISX0201_R_ENCODE(c, code)
                if (code != DBCINV) {
                    WRITE1((unsigned char)code)
                    NEXT(1, 1)
                    continue;
                }
            }

            TRYMAP_ENC(jisxcommon, code, c) {
                if (code & 0x8000) /* MSB set: JIS X 0212 */
                    return 1;
jisx0208encode: if (charset != CHARSET_JISX0208) {
                    WRITE3(ESC, '$', 'B')
                    STATE_SETG0(state, CHARSET_JISX0208)
                    NEXT_OUT(3)
                }
                WRITE2(code >> 8, code & 0xff)
                NEXT(1, 2)
            } else if (c == 0xff3c) { /* FULL-WIDTH REVERSE SOLIDUS */
                code = 0x2140;
                goto jisx0208encode;
            } else {
                JISX0201_R_ENCODE(c, code)
                else
                    return 1;
                /* if (charset == CHARSET_JISX0201_R) : already checked */
                WRITE4(ESC, '(', 'J', (unsigned char)code)
                STATE_SETG0(state, CHARSET_JISX0201_R)
                NEXT(1, 4)
            }
        }
    }

    return 0;
}

#define HAVE_DECODER_INIT
DECODER_INIT(iso2022_jp)
{
    STATE_CLEARFLAGS(state)
    STATE_SETG0(state, CHARSET_ASCII)
    STATE_SETG1(state, CHARSET_ASCII)
    return 0;
}

#define HAVE_DECODER_RESET
DECODER_RESET(iso2022_jp)
{
    STATE_CLEARFLAG(state, F_SHIFTED)
    return 0;
}

DECODER(iso2022_jp)
{
  ISO2022_LOOP_BEGIN
    unsigned char    charset, c2;

    ISO2022_GETCHARSET(charset, c)

    if (charset & CHARSET_DOUBLEBYTE) {
        /* all double byte character sets are in JIS X 0208 here.
         * this means that we don't distinguish :1978 from :1983. */
        RESERVE_INBUF(2)
        RESERVE_OUTBUF(1)
        c2 = IN2;
        if (c == 0x21 && c2 == 0x40) { /* FULL-WIDTH REVERSE SOLIDUS */
            **outbuf = 0xff3c;
            NEXT(2, 1)
        } else TRYMAP_DEC(jisx0208, **outbuf, c, c2) {
            NEXT(2, 1)
        } else
            return 2;
    } else if (charset == CHARSET_ASCII) {
        RESERVE_OUTBUF(1)
        OUT1(c)
        NEXT(1, 1)
    } else if (charset == CHARSET_JISX0201_R) {
        RESERVE_OUTBUF(1)
        JISX0201_R_DECODE(c, **outbuf)
        else
            return 1;
        NEXT(1, 1)
    } else
        return MBERR_INTERNAL;
  ISO2022_LOOP_END

  return 0;
}

#include "codecentry.h"
BEGIN_CODEC_REGISTRY(iso2022_jp)
    MAPOPEN(ja_JP)
        IMPORTMAP_DEC(jisx0208)
        IMPORTMAP_ENC(jisxcommon)
    MAPCLOSE()
END_CODEC_REGISTRY(iso2022_jp)