ref: 2707beb7b46cf29fb1ebafad33edf8d48041ed50
dir: /sys/src/cmd/tcs/jis.h/
/*
following astonishing goo courtesy of kogure.
*/
/*
* MicroSoft Kanji Encoding (SJIS) Transformation
*/
/*
* void
* J2S(unsigned char *_h, unsigned char *_l)
* JIS X 208 to MS kanji transformation.
*
* Calling/Exit State:
* _h and _l should be in their valid range.
* No return value.
*/
#define J2S(_h, _l) { \
/* lower: 21-7e >> 40-9d,9e-fb >> 40-7e,(skip 7f),80-fc */ \
if (((_l) += (((_h)-- % 2) ? 0x1f : 0x7d)) > 0x7e) (_l)++; \
/* upper: 21-7e >> 81-af >> 81-9f,(skip a0-df),e0-ef */ \
if (((_h) = ((_h) / 2 + 0x71)) > 0x9f) (_h) += 0x40; \
}
/*
* void
* S2J(unsigned char *_h, unsigned char *_l)
* MS kanji to JIS X 208 transformation.
*
* Calling/Exit State:
* _h and _l should be in valid range.
* No return value.
*/
#define S2J(_h, _l) { \
/* lower: 40-7e,80-fc >> 21-5f,61-dd >> 21-7e,7f-dc */ \
if (((_l) -= 0x1f) > 0x60) (_l)--; \
/* upper: 81-9f,e0-ef >> 00-1e,5f-6e >> 00-2e >> 21-7d */ \
if (((_h) -= 0x81) > 0x5e) (_h) -= 0x40; (_h) *= 2, (_h) += 0x21; \
/* upper: ,21-7d >> ,22-7e ; lower: ,7f-dc >> ,21-7e */ \
if ((_l) > 0x7e) (_h)++, (_l) -= 0x5e; \
}
/*
* int
* ISJKANA(const unsigned char *_b)
* Tests given byte is in the range of JIS X 0201 katakana.
*
* Calling/Exit State:
* Returns 1 if it is, or 0 otherwise.
*/
#define ISJKANA(_b) (0xa0 <= (_b) && (_b) < 0xe0)
/*
* int
* CANS2JH(const unsigned char *_h)
* Tests given byte is in the range of valid first byte of MS
* kanji code; either acts as a subroutine of CANS2J() macro
* or can be used to parse MS kanji encoded strings.
*
* Calling/Exit State:
* Returns 1 if it is, or 0 otherwise.
*/
#define CANS2JH(_h) ((0x81 <= (_h) && (_h) < 0xf0) && !ISJKANA(_h))
/*
* int
* CANS2JL(const unsigned char *_l)
* Tests given byte is in the range of valid second byte of MS
* kanji code; acts as a subroutine of CANS2J() macro.
*
* Calling/Exit State:
* Returns 1 if it is, or 0 otherwise.
*/
#define CANS2JL(_l) (0x40 <= (_l) && (_l) < 0xfd && (_l) != 0x7f)
/*
* int
* CANS2J(const unsigned char *_h, const unsinged char *_l)
* Tests given bytes form a MS kanji code point which can be
* transformed to a valid JIS X 208 code point.
*
* Calling/Exit State:
* Returns 1 if they are, or 0 otherwise.
*/
#define CANS2J(_h, _l) (CANS2JH(_h) && CANS2JL(_l))
/*
* int
* CANJ2SB(const unsigned char *_b)
* Tests given bytes is in the range of valid 94 graphic
* character set; acts as a subroutine of CANJ2S() macro.
*
* Calling/Exit State:
* Returns 1 if it is, or 0 otherwise.
*/
#define CANJ2SB(_b) (0x21 <= (_b) && (_b) < 0x7f)
/*
* int
* CANJ2S(const unsigned char *_h, const unsigned char *_l)
* Tests given bytes form valid JIS X 208 code points
* (which can be transformed to MS kanji).
*
* Calling/Exit State:
* Returns 1 if they are, or 0 otherwise.
*/
#define CANJ2S(_h, _l) (CANJ2SB(_h) && CANJ2SB(_l))