plan9port

fork of plan9port with libvec, libstr and libsdb
Log | Files | Refs | README | LICENSE

jis.h (2872B)

      1 /*
      2 	following astonishing goo courtesy of kogure.
      3 */
      4 /*
      5  * MicroSoft Kanji Encoding (SJIS) Transformation
      6  */
      7 
      8 /*
      9  * void
     10  * J2S(unsigned char *_h, unsigned char *_l)
     11  *	JIS X 208 to MS kanji transformation.
     12  *
     13  * Calling/Exit State:
     14  *	_h and _l should be in their valid range.
     15  *	No return value.
     16  */
     17 #define J2S(_h, _l) { \
     18 	/* lower: 21-7e >> 40-9d,9e-fb >> 40-7e,(skip 7f),80-fc */ \
     19 	if (((_l) += (((_h)-- % 2) ? 0x1f : 0x7d)) > 0x7e) (_l)++; \
     20 	/* upper: 21-7e >> 81-af >> 81-9f,(skip a0-df),e0-ef */ \
     21 	if (((_h) = ((_h) / 2 + 0x71)) > 0x9f) (_h) += 0x40; \
     22 }
     23 
     24 /*
     25  * void
     26  * S2J(unsigned char *_h, unsigned char *_l)
     27  *	MS kanji to JIS X 208 transformation.
     28  *
     29  * Calling/Exit State:
     30  *	_h and _l should be in valid range.
     31  *	No return value.
     32  */
     33 #define S2J(_h, _l) { \
     34 	/* lower: 40-7e,80-fc >> 21-5f,61-dd >> 21-7e,7f-dc */ \
     35 	if (((_l) -= 0x1f) > 0x60) (_l)--; \
     36 	/* upper: 81-9f,e0-ef >> 00-1e,5f-6e >> 00-2e >> 21-7d */ \
     37 	if (((_h) -= 0x81) > 0x5e) (_h) -= 0x40; (_h) *= 2, (_h) += 0x21; \
     38 	/* upper: ,21-7d >> ,22-7e ; lower: ,7f-dc >> ,21-7e */ \
     39 	if ((_l) > 0x7e) (_h)++, (_l) -= 0x5e; \
     40 }
     41 
     42 /*
     43  * int
     44  * ISJKANA(const unsigned char *_b)
     45  *	Tests given byte is in the range of JIS X 0201 katakana.
     46  *
     47  * Calling/Exit State:
     48  *	Returns 1 if it is, or 0 otherwise.
     49  */
     50 #define	ISJKANA(_b)	(0xa0 <= (_b) && (_b) < 0xe0)
     51 
     52 /*
     53  * int
     54  * CANS2JH(const unsigned char *_h)
     55  *	Tests given byte is in the range of valid first byte of MS
     56  *	kanji code; either acts as a subroutine of CANS2J() macro
     57  *	or can be used to parse MS kanji encoded strings.
     58  *
     59  * Calling/Exit State:
     60  *	Returns 1 if it is, or 0 otherwise.
     61  */
     62 #define CANS2JH(_h)	((0x81 <= (_h) && (_h) < 0xf0) && !ISJKANA(_h))
     63 
     64 /*
     65  * int
     66  * CANS2JL(const unsigned char *_l)
     67  *	Tests given byte is in the range of valid second byte of MS
     68  *	kanji code; acts as a subroutine of CANS2J() macro.
     69  *
     70  * Calling/Exit State:
     71  *	Returns 1 if it is, or 0 otherwise.
     72  */
     73 #define CANS2JL(_l)	(0x40 <= (_l) && (_l) < 0xfd && (_l) != 0x7f)
     74 
     75 /*
     76  * int
     77  * CANS2J(const unsigned char *_h, const unsinged char *_l)
     78  *	Tests given bytes form a MS kanji code point which can be
     79  *	transformed to a valid JIS X 208 code point.
     80  *
     81  * Calling/Exit State:
     82  *	Returns 1 if they are, or 0 otherwise.
     83  */
     84 #define CANS2J(_h, _l)  (CANS2JH(_h) && CANS2JL(_l))
     85 
     86 /*
     87  * int
     88  * CANJ2SB(const unsigned char *_b)
     89  *	Tests given bytes is in the range of valid 94 graphic
     90  *	character set; acts as a subroutine of CANJ2S() macro.
     91  *
     92  * Calling/Exit State:
     93  *	Returns 1 if it is, or 0 otherwise.
     94  */
     95 #define CANJ2SB(_b)	(0x21 <= (_b) && (_b) < 0x7f)
     96 
     97 /*
     98  * int
     99  * CANJ2S(const unsigned char *_h, const unsigned char *_l)
    100  *	Tests given bytes form valid JIS X 208 code points
    101  *	(which can be transformed to MS kanji).
    102  *
    103  * Calling/Exit State:
    104  *	Returns 1 if they are, or 0 otherwise.
    105  */
    106 #define CANJ2S(_h, _l)	(CANJ2SB(_h) && CANJ2SB(_l))