diff options
Diffstat (limited to 'nx-X11/lib/X11/lcUniConv/big5_emacs.h')
-rw-r--r-- | nx-X11/lib/X11/lcUniConv/big5_emacs.h | 163 |
1 files changed, 163 insertions, 0 deletions
diff --git a/nx-X11/lib/X11/lcUniConv/big5_emacs.h b/nx-X11/lib/X11/lcUniConv/big5_emacs.h new file mode 100644 index 000000000..246aebeb4 --- /dev/null +++ b/nx-X11/lib/X11/lcUniConv/big5_emacs.h @@ -0,0 +1,163 @@ + +/* + * BIG5-0 and BIG5-1 + */ + +/* + BIG5 with its 13494 characters doesn't fit in a single 94x94 or 96x96 + block. Therefore Emacs/Mule developers, in a typically Japanese way of + thinking, have developed an alternative encoding of BIG5 in two 94x94 + planes, very similar to the SHIFT_JIS encoding for JISX0208. + + Conversion between BIG5 codes (s1,s2) and BIG5-0 codes (c1,c2): + Example. (s1,s2) = 0xA140, (c1,c2) = 0x2121. + 0xA1 <= s1 <= 0xC7, 0x40 <= s2 <= 0x7E || 0xA1 <= s2 <= 0xFE, + 0x21 <= c1 <= 0x62, 0x21 <= c2 <= 0x7E. + Invariant: + 157*(s1-0xA1) + (s2 < 0x80 ? s2-0x40 : s2-0x62) + = 94*(c1-0x21)+(c2-0x21) + Conversion (s1,s2) -> (c1,c2): + t := 157*(s1-0xA1) + (s2 < 0x80 ? s2-0x40 : s2-0x62) + c1 := (t div 94) + 0x21 + c2 := (t mod 94) + 0x21 + Conversion (c1,c2) -> (s1,s2): + t := 94*(c1-0x21)+(c2-0x21) + t2 := t mod 157 + s1 := (t div 157) + 0xA1 + s2 := (t2 < 0x3F ? t2+0x40 : t2+0x62) + + Conversion between BIG5 codes (s1,s2) and BIG5-1 codes (c1,c2): + Example. (s1,s2) = 0xC940, (c1,c2) = 0x2121. + 0xC9 <= s1 <= 0xF9, 0x40 <= s2 <= 0x7E || 0xA1 <= s2 <= 0xFE, + 0x21 <= c1 <= 0x72, 0x21 <= c2 <= 0x7E. + Invariant: + 157*(s1-0xC9) + (s2 < 0x80 ? s2-0x40 : s2-0x62) + = 94*(c1-0x21)+(c2-0x21) + Conversion (s1,s2) -> (c1,c2): + t := 157*(s1-0xC9) + (s2 < 0x80 ? s2-0x40 : s2-0x62) + c1 := (t div 94) + 0x21 + c2 := (t mod 94) + 0x21 + Conversion (c1,c2) -> (s1,s2): + t := 94*(c1-0x21)+(c2-0x21) + t2 := t mod 157 + s1 := (t div 157) + 0xC9 + s2 := (t2 < 0x3F ? t2+0x40 : t2+0x62) + */ + +static int +big5_0_mbtowc (conv_t conv, ucs4_t *pwc, const unsigned char *s, int n) +{ + unsigned char c1 = s[0]; + if (c1 >= 0x21 && c1 <= 0x62) { + if (n >= 2) { + unsigned char c2 = s[1]; + if (c2 >= 0x21 && c2 <= 0x7e) { + unsigned int i = 94 * (c1 - 0x21) + (c2 - 0x21); + if (0) { + /* Unoptimized. */ + unsigned char buf[2]; + buf[0] = (i / 157) + 0xa1; + i = i % 157; + buf[1] = i + (i < 0x3f ? 0x40 : 0x62); + return big5_mbtowc(conv,pwc,buf,2); + } else { + /* Inline the implementation of big5_mbtowc. */ + if (i < 6121) { + unsigned short wc = big5_2uni_pagea1[i]; + if (wc != 0xfffd) { + *pwc = (ucs4_t) wc; + return 2; + } + } + } + } + return RET_ILSEQ; + } + return RET_TOOFEW(0); + } + return RET_ILSEQ; +} + +static int +big5_1_mbtowc (conv_t conv, ucs4_t *pwc, const unsigned char *s, int n) +{ + unsigned char c1 = s[0]; + if (c1 >= 0x21 && c1 <= 0x72) { + if (n >= 2) { + unsigned char c2 = s[1]; + if (c2 >= 0x21 && c2 <= 0x7e) { + unsigned int i = 94 * (c1 - 0x21) + (c2 - 0x21); + if (0) { + /* Unoptimized. */ + unsigned char buf[2]; + buf[0] = (i / 157) + 0xc9; + i = i % 157; + buf[1] = i + (i < 0x3f ? 0x40 : 0x62); + return big5_mbtowc(conv,pwc,buf,2); + } else { + /* Inline the implementation of big5_mbtowc. */ + if (i < 7652) { + unsigned short wc = big5_2uni_pagec9[i]; + if (wc != 0xfffd) { + *pwc = (ucs4_t) wc; + return 2; + } + } + } + } + return RET_ILSEQ; + } + return RET_TOOFEW(0); + } + return RET_ILSEQ; +} + +static int +big5_0_wctomb (conv_t conv, unsigned char *r, ucs4_t wc, int n) +{ + if (n >= 2) { + unsigned char buf[2]; + int ret = big5_wctomb(conv,buf,wc,2); + if (ret != RET_ILSEQ) { + unsigned char s1, s2; + if (ret != 2) abort(); + s1 = buf[0]; + s2 = buf[1]; + if (!(s1 >= 0xa1)) abort(); + if (!((s2 >= 0x40 && s2 <= 0x7e) || (s2 >= 0xa1 && s2 <= 0xfe))) abort(); + if (s1 < 0xc9) { + unsigned int t = 157 * (s1 - 0xa1) + s2 - (s2 < 0x80 ? 0x40 : 0x62); + r[0] = (t / 94) + 0x21; + r[1] = (t % 94) + 0x21; + return 2; + } + } + return RET_ILSEQ; + } + return RET_TOOSMALL; +} + +static int +big5_1_wctomb (conv_t conv, unsigned char *r, ucs4_t wc, int n) +{ + if (n >= 2) { + unsigned char buf[2]; + int ret = big5_wctomb(conv,buf,wc,2); + if (ret != RET_ILSEQ) { + unsigned char s1, s2; + if (ret != 2) abort(); + s1 = buf[0]; + s2 = buf[1]; + if (!(s1 <= 0xf9)) abort(); + if (!((s2 >= 0x40 && s2 <= 0x7e) || (s2 >= 0xa1 && s2 <= 0xfe))) abort(); + if (s1 >= 0xc9) { + unsigned int t = 157 * (s1 - 0xc9) + s2 - (s2 < 0x80 ? 0x40 : 0x62); + r[0] = (t / 94) + 0x21; + r[1] = (t % 94) + 0x21; + return 2; + } + } + return RET_ILSEQ; + } + return RET_TOOSMALL; +} |