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Diffstat (limited to 'src/arabic.c')
| -rw-r--r-- | src/arabic.c | 396 |
1 files changed, 396 insertions, 0 deletions
diff --git a/src/arabic.c b/src/arabic.c new file mode 100644 index 0000000..f64dab2 --- /dev/null +++ b/src/arabic.c @@ -0,0 +1,396 @@ +/* vi:set ts=8 sts=4 sw=4 noet: + * + * VIM - Vi IMproved by Bram Moolenaar + * + * Do ":help uganda" in Vim to read copying and usage conditions. + * Do ":help credits" in Vim to see a list of people who contributed. + * See README.txt for an overview of the Vim source code. + */ + +/* + * arabic.c: functions for Arabic language + * + * Author: Nadim Shaikli & Isam Bayazidi + * Farsi support and restructuring to make adding new letters easier by Ali + * Gholami Rudi. Further work by Ameretat Reith. + */ + +/* + * Sorted list of unicode Arabic characters. Each entry holds the + * presentation forms of a letter. + * + * Arabic characters are categorized into following types: + * + * Isolated - iso-8859-6 form + * Initial - unicode form-B start + * Medial - unicode form-B middle + * Final - unicode form-B final + * Stand-Alone - unicode form-B isolated + */ + +#include "vim.h" + +#if defined(FEAT_ARABIC) || defined(PROTO) + +// Unicode values for Arabic characters. +#define a_HAMZA 0x0621 +#define a_ALEF_MADDA 0x0622 +#define a_ALEF_HAMZA_ABOVE 0x0623 +#define a_WAW_HAMZA 0x0624 +#define a_ALEF_HAMZA_BELOW 0x0625 +#define a_YEH_HAMZA 0x0626 +#define a_ALEF 0x0627 +#define a_BEH 0x0628 +#define a_TEH_MARBUTA 0x0629 +#define a_TEH 0x062a +#define a_THEH 0x062b +#define a_JEEM 0x062c +#define a_HAH 0x062d +#define a_KHAH 0x062e +#define a_DAL 0x062f +#define a_THAL 0x0630 +#define a_REH 0x0631 +#define a_ZAIN 0x0632 +#define a_SEEN 0x0633 +#define a_SHEEN 0x0634 +#define a_SAD 0x0635 +#define a_DAD 0x0636 +#define a_TAH 0x0637 +#define a_ZAH 0x0638 +#define a_AIN 0x0639 +#define a_GHAIN 0x063a +#define a_TATWEEL 0x0640 +#define a_FEH 0x0641 +#define a_QAF 0x0642 +#define a_KAF 0x0643 +#define a_LAM 0x0644 +#define a_MEEM 0x0645 +#define a_NOON 0x0646 +#define a_HEH 0x0647 +#define a_WAW 0x0648 +#define a_ALEF_MAKSURA 0x0649 +#define a_YEH 0x064a +#define a_FATHATAN 0x064b +#define a_DAMMATAN 0x064c +#define a_KASRATAN 0x064d +#define a_FATHA 0x064e +#define a_DAMMA 0x064f +#define a_KASRA 0x0650 +#define a_SHADDA 0x0651 +#define a_SUKUN 0x0652 +#define a_MADDA_ABOVE 0x0653 +#define a_HAMZA_ABOVE 0x0654 +#define a_HAMZA_BELOW 0x0655 + +#define a_PEH 0x067e +#define a_TCHEH 0x0686 +#define a_JEH 0x0698 +#define a_FKAF 0x06a9 +#define a_GAF 0x06af +#define a_FYEH 0x06cc + +#define a_s_LAM_ALEF_MADDA_ABOVE 0xfef5 +#define a_f_LAM_ALEF_MADDA_ABOVE 0xfef6 +#define a_s_LAM_ALEF_HAMZA_ABOVE 0xfef7 +#define a_f_LAM_ALEF_HAMZA_ABOVE 0xfef8 +#define a_s_LAM_ALEF_HAMZA_BELOW 0xfef9 +#define a_f_LAM_ALEF_HAMZA_BELOW 0xfefa +#define a_s_LAM_ALEF 0xfefb +#define a_f_LAM_ALEF 0xfefc + +static struct achar { + unsigned c; + unsigned isolated; + unsigned initial; + unsigned medial; + unsigned final; +} achars[] = { + {a_HAMZA, 0xfe80, 0, 0, 0}, + {a_ALEF_MADDA, 0xfe81, 0, 0, 0xfe82}, + {a_ALEF_HAMZA_ABOVE, 0xfe83, 0, 0, 0xfe84}, + {a_WAW_HAMZA, 0xfe85, 0, 0, 0xfe86}, + {a_ALEF_HAMZA_BELOW, 0xfe87, 0, 0, 0xfe88}, + {a_YEH_HAMZA, 0xfe89, 0xfe8b, 0xfe8c, 0xfe8a}, + {a_ALEF, 0xfe8d, 0, 0, 0xfe8e}, + {a_BEH, 0xfe8f, 0xfe91, 0xfe92, 0xfe90}, + {a_TEH_MARBUTA, 0xfe93, 0, 0, 0xfe94}, + {a_TEH, 0xfe95, 0xfe97, 0xfe98, 0xfe96}, + {a_THEH, 0xfe99, 0xfe9b, 0xfe9c, 0xfe9a}, + {a_JEEM, 0xfe9d, 0xfe9f, 0xfea0, 0xfe9e}, + {a_HAH, 0xfea1, 0xfea3, 0xfea4, 0xfea2}, + {a_KHAH, 0xfea5, 0xfea7, 0xfea8, 0xfea6}, + {a_DAL, 0xfea9, 0, 0, 0xfeaa}, + {a_THAL, 0xfeab, 0, 0, 0xfeac}, + {a_REH, 0xfead, 0, 0, 0xfeae}, + {a_ZAIN, 0xfeaf, 0, 0, 0xfeb0}, + {a_SEEN, 0xfeb1, 0xfeb3, 0xfeb4, 0xfeb2}, + {a_SHEEN, 0xfeb5, 0xfeb7, 0xfeb8, 0xfeb6}, + {a_SAD, 0xfeb9, 0xfebb, 0xfebc, 0xfeba}, + {a_DAD, 0xfebd, 0xfebf, 0xfec0, 0xfebe}, + {a_TAH, 0xfec1, 0xfec3, 0xfec4, 0xfec2}, + {a_ZAH, 0xfec5, 0xfec7, 0xfec8, 0xfec6}, + {a_AIN, 0xfec9, 0xfecb, 0xfecc, 0xfeca}, + {a_GHAIN, 0xfecd, 0xfecf, 0xfed0, 0xfece}, + {a_TATWEEL, 0, 0x0640, 0x0640, 0x0640}, + {a_FEH, 0xfed1, 0xfed3, 0xfed4, 0xfed2}, + {a_QAF, 0xfed5, 0xfed7, 0xfed8, 0xfed6}, + {a_KAF, 0xfed9, 0xfedb, 0xfedc, 0xfeda}, + {a_LAM, 0xfedd, 0xfedf, 0xfee0, 0xfede}, + {a_MEEM, 0xfee1, 0xfee3, 0xfee4, 0xfee2}, + {a_NOON, 0xfee5, 0xfee7, 0xfee8, 0xfee6}, + {a_HEH, 0xfee9, 0xfeeb, 0xfeec, 0xfeea}, + {a_WAW, 0xfeed, 0, 0, 0xfeee}, + {a_ALEF_MAKSURA, 0xfeef, 0, 0, 0xfef0}, + {a_YEH, 0xfef1, 0xfef3, 0xfef4, 0xfef2}, + {a_FATHATAN, 0xfe70, 0, 0, 0}, + {a_DAMMATAN, 0xfe72, 0, 0, 0}, + {a_KASRATAN, 0xfe74, 0, 0, 0}, + {a_FATHA, 0xfe76, 0, 0xfe77, 0}, + {a_DAMMA, 0xfe78, 0, 0xfe79, 0}, + {a_KASRA, 0xfe7a, 0, 0xfe7b, 0}, + {a_SHADDA, 0xfe7c, 0, 0xfe7c, 0}, + {a_SUKUN, 0xfe7e, 0, 0xfe7f, 0}, + {a_MADDA_ABOVE, 0, 0, 0, 0}, + {a_HAMZA_ABOVE, 0, 0, 0, 0}, + {a_HAMZA_BELOW, 0, 0, 0, 0}, + {a_PEH, 0xfb56, 0xfb58, 0xfb59, 0xfb57}, + {a_TCHEH, 0xfb7a, 0xfb7c, 0xfb7d, 0xfb7b}, + {a_JEH, 0xfb8a, 0, 0, 0xfb8b}, + {a_FKAF, 0xfb8e, 0xfb90, 0xfb91, 0xfb8f}, + {a_GAF, 0xfb92, 0xfb94, 0xfb95, 0xfb93}, + {a_FYEH, 0xfbfc, 0xfbfe, 0xfbff, 0xfbfd}, +}; + +#define a_BYTE_ORDER_MARK 0xfeff + +/* + * Find the struct achar pointer to the given Arabic char. + * Returns NULL if not found. + */ + static struct achar * +find_achar(int c) +{ + int h, m, l; + + // using binary search to find c + h = ARRAY_LENGTH(achars); + l = 0; + while (l < h) + { + m = (h + l) / 2; + if (achars[m].c == (unsigned)c) + return &achars[m]; + if ((unsigned)c < achars[m].c) + h = m; + else + l = m + 1; + } + return NULL; +} + +/* + * Change shape - from Combination (2 char) to an Isolated + */ + static int +chg_c_laa2i(int hid_c) +{ + int tempc; + + switch (hid_c) + { + case a_ALEF_MADDA: + tempc = a_s_LAM_ALEF_MADDA_ABOVE; + break; + case a_ALEF_HAMZA_ABOVE: + tempc = a_s_LAM_ALEF_HAMZA_ABOVE; + break; + case a_ALEF_HAMZA_BELOW: + tempc = a_s_LAM_ALEF_HAMZA_BELOW; + break; + case a_ALEF: + tempc = a_s_LAM_ALEF; + break; + default: + tempc = 0; + } + + return tempc; +} + +/* + * Change shape - from Combination-Isolated to Final + */ + static int +chg_c_laa2f(int hid_c) +{ + int tempc; + + switch (hid_c) + { + case a_ALEF_MADDA: + tempc = a_f_LAM_ALEF_MADDA_ABOVE; + break; + case a_ALEF_HAMZA_ABOVE: + tempc = a_f_LAM_ALEF_HAMZA_ABOVE; + break; + case a_ALEF_HAMZA_BELOW: + tempc = a_f_LAM_ALEF_HAMZA_BELOW; + break; + case a_ALEF: + tempc = a_f_LAM_ALEF; + break; + default: + tempc = 0; + } + + return tempc; +} + +/* + * Returns whether it is possible to join the given letters + */ + static int +can_join(int c1, int c2) +{ + struct achar *a1 = find_achar(c1); + struct achar *a2 = find_achar(c2); + + return a1 && a2 && (a1->initial || a1->medial) && (a2->final || a2->medial); +} + +/* + * Check whether we are dealing with a character that could be regarded as an + * Arabic combining character, need to check the character before this. + */ + int +arabic_maycombine(int two) +{ + if (p_arshape && !p_tbidi) + return (two == a_ALEF_MADDA + || two == a_ALEF_HAMZA_ABOVE + || two == a_ALEF_HAMZA_BELOW + || two == a_ALEF); + return FALSE; +} + +/* + * Check whether we are dealing with Arabic combining characters. + * Note: these are NOT really composing characters! + */ + int +arabic_combine( + int one, // first character + int two) // character just after "one" +{ + if (one == a_LAM) + return arabic_maycombine(two); + return FALSE; +} + +/* + * A_is_iso returns true if 'c' is an Arabic ISO-8859-6 character + * (alphabet/number/punctuation) + */ + static int +A_is_iso(int c) +{ + return find_achar(c) != NULL; +} + +/* + * A_is_ok returns true if 'c' is an Arabic 10646 (8859-6 or Form-B) + */ + static int +A_is_ok(int c) +{ + return (A_is_iso(c) || c == a_BYTE_ORDER_MARK); +} + +/* + * A_is_valid returns true if 'c' is an Arabic 10646 (8859-6 or Form-B) + * with some exceptions/exclusions + */ + static int +A_is_valid(int c) +{ + return (A_is_ok(c) && c != a_HAMZA); +} + +/* + * Do Arabic shaping on character "c". Returns the shaped character. + * out: "ccp" points to the first byte of the character to be shaped. + * in/out: "c1p" points to the first composing char for "c". + * in: "prev_c" is the previous character (not shaped) + * in: "prev_c1" is the first composing char for the previous char + * (not shaped) + * in: "next_c" is the next character (not shaped). + */ + int +arabic_shape( + int c, + int *ccp, + int *c1p, + int prev_c, + int prev_c1, + int next_c) +{ + int curr_c; + int curr_laa; + int prev_laa; + + // Deal only with Arabic characters, pass back all others + if (!A_is_ok(c)) + return c; + + curr_laa = arabic_combine(c, *c1p); + prev_laa = arabic_combine(prev_c, prev_c1); + + if (curr_laa) + { + if (A_is_valid(prev_c) && can_join(prev_c, a_LAM) && !prev_laa) + curr_c = chg_c_laa2f(*c1p); + else + curr_c = chg_c_laa2i(*c1p); + + // Remove the composing character + *c1p = 0; + } + else + { + struct achar *curr_a = find_achar(c); + int backward_combine = !prev_laa && can_join(prev_c, c); + int forward_combine = can_join(c, next_c); + + if (backward_combine) + { + if (forward_combine) + curr_c = curr_a->medial; + else + curr_c = curr_a->final; + } + else + { + if (forward_combine) + curr_c = curr_a->initial; + else + curr_c = curr_a->isolated; + } + } + + // Character missing from the table means using original character. + if (curr_c == NUL) + curr_c = c; + + if (curr_c != c && ccp != NULL) + { + char_u buf[MB_MAXBYTES + 1]; + + // Update the first byte of the character. + (*mb_char2bytes)(curr_c, buf); + *ccp = buf[0]; + } + + // Return the shaped character + return curr_c; +} +#endif // FEAT_ARABIC |