blob: 1c3059839207142ea6e4e1ced6ac2c4f86d86d48 [file] [log] [blame]
/* vi:set ts=8 sts=4 sw=4:
*
* 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
*
* Included by main.c, when FEAT_ARABIC & FEAT_GUI is defined.
*
* --
*
* Author: Nadim Shaikli & Isam Bayazidi
*
*/
static int A_is_a(int cur_c);
static int A_is_s(int cur_c);
static int A_is_f(int cur_c);
static int chg_c_a2s(int cur_c);
static int chg_c_a2i(int cur_c);
static int chg_c_a2m(int cur_c);
static int chg_c_a2f(int cur_c);
static int chg_c_i2m(int cur_c);
static int chg_c_f2m(int cur_c);
static int chg_c_laa2i(int hid_c);
static int chg_c_laa2f(int hid_c);
static int half_shape(int c);
static int A_firstc_laa(int c1, int c);
static int A_is_harakat(int c);
static int A_is_iso(int c);
static int A_is_formb(int c);
static int A_is_ok(int c);
static int A_is_valid(int c);
static int A_is_special(int c);
/*
* Returns True if c is an ISO-8859-6 shaped ARABIC letter (user entered)
*/
static int
A_is_a(int cur_c)
{
switch (cur_c)
{
case a_HAMZA:
case a_ALEF_MADDA:
case a_ALEF_HAMZA_ABOVE:
case a_WAW_HAMZA:
case a_ALEF_HAMZA_BELOW:
case a_YEH_HAMZA:
case a_ALEF:
case a_BEH:
case a_TEH_MARBUTA:
case a_TEH:
case a_THEH:
case a_JEEM:
case a_HAH:
case a_KHAH:
case a_DAL:
case a_THAL:
case a_REH:
case a_ZAIN:
case a_SEEN:
case a_SHEEN:
case a_SAD:
case a_DAD:
case a_TAH:
case a_ZAH:
case a_AIN:
case a_GHAIN:
case a_TATWEEL:
case a_FEH:
case a_QAF:
case a_KAF:
case a_LAM:
case a_MEEM:
case a_NOON:
case a_HEH:
case a_WAW:
case a_ALEF_MAKSURA:
case a_YEH:
return TRUE;
}
return FALSE;
}
/*
* Returns True if c is an Isolated Form-B ARABIC letter
*/
static int
A_is_s(int cur_c)
{
switch (cur_c)
{
case a_s_HAMZA:
case a_s_ALEF_MADDA:
case a_s_ALEF_HAMZA_ABOVE:
case a_s_WAW_HAMZA:
case a_s_ALEF_HAMZA_BELOW:
case a_s_YEH_HAMZA:
case a_s_ALEF:
case a_s_BEH:
case a_s_TEH_MARBUTA:
case a_s_TEH:
case a_s_THEH:
case a_s_JEEM:
case a_s_HAH:
case a_s_KHAH:
case a_s_DAL:
case a_s_THAL:
case a_s_REH:
case a_s_ZAIN:
case a_s_SEEN:
case a_s_SHEEN:
case a_s_SAD:
case a_s_DAD:
case a_s_TAH:
case a_s_ZAH:
case a_s_AIN:
case a_s_GHAIN:
case a_s_FEH:
case a_s_QAF:
case a_s_KAF:
case a_s_LAM:
case a_s_MEEM:
case a_s_NOON:
case a_s_HEH:
case a_s_WAW:
case a_s_ALEF_MAKSURA:
case a_s_YEH:
return TRUE;
}
return FALSE;
}
/*
* Returns True if c is a Final shape of an ARABIC letter
*/
static int
A_is_f(int cur_c)
{
switch (cur_c)
{
case a_f_ALEF_MADDA:
case a_f_ALEF_HAMZA_ABOVE:
case a_f_WAW_HAMZA:
case a_f_ALEF_HAMZA_BELOW:
case a_f_YEH_HAMZA:
case a_f_ALEF:
case a_f_BEH:
case a_f_TEH_MARBUTA:
case a_f_TEH:
case a_f_THEH:
case a_f_JEEM:
case a_f_HAH:
case a_f_KHAH:
case a_f_DAL:
case a_f_THAL:
case a_f_REH:
case a_f_ZAIN:
case a_f_SEEN:
case a_f_SHEEN:
case a_f_SAD:
case a_f_DAD:
case a_f_TAH:
case a_f_ZAH:
case a_f_AIN:
case a_f_GHAIN:
case a_f_FEH:
case a_f_QAF:
case a_f_KAF:
case a_f_LAM:
case a_f_MEEM:
case a_f_NOON:
case a_f_HEH:
case a_f_WAW:
case a_f_ALEF_MAKSURA:
case a_f_YEH:
case a_f_LAM_ALEF_MADDA_ABOVE:
case a_f_LAM_ALEF_HAMZA_ABOVE:
case a_f_LAM_ALEF_HAMZA_BELOW:
case a_f_LAM_ALEF:
return TRUE;
}
return FALSE;
}
/*
* Change shape - from ISO-8859-6/Isolated to Form-B Isolated
*/
static int
chg_c_a2s(int cur_c)
{
int tempc;
switch (cur_c)
{
case a_HAMZA:
tempc = a_s_HAMZA;
break;
case a_ALEF_MADDA:
tempc = a_s_ALEF_MADDA;
break;
case a_ALEF_HAMZA_ABOVE:
tempc = a_s_ALEF_HAMZA_ABOVE;
break;
case a_WAW_HAMZA:
tempc = a_s_WAW_HAMZA;
break;
case a_ALEF_HAMZA_BELOW:
tempc = a_s_ALEF_HAMZA_BELOW;
break;
case a_YEH_HAMZA:
tempc = a_s_YEH_HAMZA;
break;
case a_ALEF:
tempc = a_s_ALEF;
break;
case a_TEH_MARBUTA:
tempc = a_s_TEH_MARBUTA;
break;
case a_DAL:
tempc = a_s_DAL;
break;
case a_THAL:
tempc = a_s_THAL;
break;
case a_REH:
tempc = a_s_REH;
break;
case a_ZAIN:
tempc = a_s_ZAIN;
break;
case a_TATWEEL: /* exceptions */
tempc = cur_c;
break;
case a_WAW:
tempc = a_s_WAW;
break;
case a_ALEF_MAKSURA:
tempc = a_s_ALEF_MAKSURA;
break;
case a_BEH:
tempc = a_s_BEH;
break;
case a_TEH:
tempc = a_s_TEH;
break;
case a_THEH:
tempc = a_s_THEH;
break;
case a_JEEM:
tempc = a_s_JEEM;
break;
case a_HAH:
tempc = a_s_HAH;
break;
case a_KHAH:
tempc = a_s_KHAH;
break;
case a_SEEN:
tempc = a_s_SEEN;
break;
case a_SHEEN:
tempc = a_s_SHEEN;
break;
case a_SAD:
tempc = a_s_SAD;
break;
case a_DAD:
tempc = a_s_DAD;
break;
case a_TAH:
tempc = a_s_TAH;
break;
case a_ZAH:
tempc = a_s_ZAH;
break;
case a_AIN:
tempc = a_s_AIN;
break;
case a_GHAIN:
tempc = a_s_GHAIN;
break;
case a_FEH:
tempc = a_s_FEH;
break;
case a_QAF:
tempc = a_s_QAF;
break;
case a_KAF:
tempc = a_s_KAF;
break;
case a_LAM:
tempc = a_s_LAM;
break;
case a_MEEM:
tempc = a_s_MEEM;
break;
case a_NOON:
tempc = a_s_NOON;
break;
case a_HEH:
tempc = a_s_HEH;
break;
case a_YEH:
tempc = a_s_YEH;
break;
default:
tempc = 0;
}
return tempc;
}
/*
* Change shape - from ISO-8859-6/Isolated to Initial
*/
static int
chg_c_a2i(int cur_c)
{
int tempc;
switch (cur_c)
{
case a_YEH_HAMZA:
tempc = a_i_YEH_HAMZA;
break;
case a_HAMZA: /* exceptions */
tempc = a_s_HAMZA;
break;
case a_ALEF_MADDA: /* exceptions */
tempc = a_s_ALEF_MADDA;
break;
case a_ALEF_HAMZA_ABOVE: /* exceptions */
tempc = a_s_ALEF_HAMZA_ABOVE;
break;
case a_WAW_HAMZA: /* exceptions */
tempc = a_s_WAW_HAMZA;
break;
case a_ALEF_HAMZA_BELOW: /* exceptions */
tempc = a_s_ALEF_HAMZA_BELOW;
break;
case a_ALEF: /* exceptions */
tempc = a_s_ALEF;
break;
case a_TEH_MARBUTA: /* exceptions */
tempc = a_s_TEH_MARBUTA;
break;
case a_DAL: /* exceptions */
tempc = a_s_DAL;
break;
case a_THAL: /* exceptions */
tempc = a_s_THAL;
break;
case a_REH: /* exceptions */
tempc = a_s_REH;
break;
case a_ZAIN: /* exceptions */
tempc = a_s_ZAIN;
break;
case a_TATWEEL: /* exceptions */
tempc = cur_c;
break;
case a_WAW: /* exceptions */
tempc = a_s_WAW;
break;
case a_ALEF_MAKSURA: /* exceptions */
tempc = a_s_ALEF_MAKSURA;
break;
case a_BEH:
tempc = a_i_BEH;
break;
case a_TEH:
tempc = a_i_TEH;
break;
case a_THEH:
tempc = a_i_THEH;
break;
case a_JEEM:
tempc = a_i_JEEM;
break;
case a_HAH:
tempc = a_i_HAH;
break;
case a_KHAH:
tempc = a_i_KHAH;
break;
case a_SEEN:
tempc = a_i_SEEN;
break;
case a_SHEEN:
tempc = a_i_SHEEN;
break;
case a_SAD:
tempc = a_i_SAD;
break;
case a_DAD:
tempc = a_i_DAD;
break;
case a_TAH:
tempc = a_i_TAH;
break;
case a_ZAH:
tempc = a_i_ZAH;
break;
case a_AIN:
tempc = a_i_AIN;
break;
case a_GHAIN:
tempc = a_i_GHAIN;
break;
case a_FEH:
tempc = a_i_FEH;
break;
case a_QAF:
tempc = a_i_QAF;
break;
case a_KAF:
tempc = a_i_KAF;
break;
case a_LAM:
tempc = a_i_LAM;
break;
case a_MEEM:
tempc = a_i_MEEM;
break;
case a_NOON:
tempc = a_i_NOON;
break;
case a_HEH:
tempc = a_i_HEH;
break;
case a_YEH:
tempc = a_i_YEH;
break;
default:
tempc = 0;
}
return tempc;
}
/*
* Change shape - from ISO-8859-6/Isolated to Medial
*/
static int
chg_c_a2m(int cur_c)
{
int tempc;
switch (cur_c)
{
case a_HAMZA: /* exception */
tempc = a_s_HAMZA;
break;
case a_ALEF_MADDA: /* exception */
tempc = a_f_ALEF_MADDA;
break;
case a_ALEF_HAMZA_ABOVE: /* exception */
tempc = a_f_ALEF_HAMZA_ABOVE;
break;
case a_WAW_HAMZA: /* exception */
tempc = a_f_WAW_HAMZA;
break;
case a_ALEF_HAMZA_BELOW: /* exception */
tempc = a_f_ALEF_HAMZA_BELOW;
break;
case a_YEH_HAMZA:
tempc = a_m_YEH_HAMZA;
break;
case a_ALEF: /* exception */
tempc = a_f_ALEF;
break;
case a_BEH:
tempc = a_m_BEH;
break;
case a_TEH_MARBUTA: /* exception */
tempc = a_f_TEH_MARBUTA;
break;
case a_TEH:
tempc = a_m_TEH;
break;
case a_THEH:
tempc = a_m_THEH;
break;
case a_JEEM:
tempc = a_m_JEEM;
break;
case a_HAH:
tempc = a_m_HAH;
break;
case a_KHAH:
tempc = a_m_KHAH;
break;
case a_DAL: /* exception */
tempc = a_f_DAL;
break;
case a_THAL: /* exception */
tempc = a_f_THAL;
break;
case a_REH: /* exception */
tempc = a_f_REH;
break;
case a_ZAIN: /* exception */
tempc = a_f_ZAIN;
break;
case a_SEEN:
tempc = a_m_SEEN;
break;
case a_SHEEN:
tempc = a_m_SHEEN;
break;
case a_SAD:
tempc = a_m_SAD;
break;
case a_DAD:
tempc = a_m_DAD;
break;
case a_TAH:
tempc = a_m_TAH;
break;
case a_ZAH:
tempc = a_m_ZAH;
break;
case a_AIN:
tempc = a_m_AIN;
break;
case a_GHAIN:
tempc = a_m_GHAIN;
break;
case a_TATWEEL: /* exception */
tempc = cur_c;
break;
case a_FEH:
tempc = a_m_FEH;
break;
case a_QAF:
tempc = a_m_QAF;
break;
case a_KAF:
tempc = a_m_KAF;
break;
case a_LAM:
tempc = a_m_LAM;
break;
case a_MEEM:
tempc = a_m_MEEM;
break;
case a_NOON:
tempc = a_m_NOON;
break;
case a_HEH:
tempc = a_m_HEH;
break;
case a_WAW: /* exception */
tempc = a_f_WAW;
break;
case a_ALEF_MAKSURA: /* exception */
tempc = a_f_ALEF_MAKSURA;
break;
case a_YEH:
tempc = a_m_YEH;
break;
default:
tempc = 0;
}
return tempc;
}
/*
* Change shape - from ISO-8859-6/Isolated to final
*/
static int
chg_c_a2f(int cur_c)
{
int tempc;
/* NOTE: these encodings need to be accounted for
a_f_ALEF_MADDA;
a_f_ALEF_HAMZA_ABOVE;
a_f_ALEF_HAMZA_BELOW;
a_f_LAM_ALEF_MADDA_ABOVE;
a_f_LAM_ALEF_HAMZA_ABOVE;
a_f_LAM_ALEF_HAMZA_BELOW;
*/
switch (cur_c)
{
case a_HAMZA: /* exception */
tempc = a_s_HAMZA;
break;
case a_ALEF_MADDA:
tempc = a_f_ALEF_MADDA;
break;
case a_ALEF_HAMZA_ABOVE:
tempc = a_f_ALEF_HAMZA_ABOVE;
break;
case a_WAW_HAMZA:
tempc = a_f_WAW_HAMZA;
break;
case a_ALEF_HAMZA_BELOW:
tempc = a_f_ALEF_HAMZA_BELOW;
break;
case a_YEH_HAMZA:
tempc = a_f_YEH_HAMZA;
break;
case a_ALEF:
tempc = a_f_ALEF;
break;
case a_BEH:
tempc = a_f_BEH;
break;
case a_TEH_MARBUTA:
tempc = a_f_TEH_MARBUTA;
break;
case a_TEH:
tempc = a_f_TEH;
break;
case a_THEH:
tempc = a_f_THEH;
break;
case a_JEEM:
tempc = a_f_JEEM;
break;
case a_HAH:
tempc = a_f_HAH;
break;
case a_KHAH:
tempc = a_f_KHAH;
break;
case a_DAL:
tempc = a_f_DAL;
break;
case a_THAL:
tempc = a_f_THAL;
break;
case a_REH:
tempc = a_f_REH;
break;
case a_ZAIN:
tempc = a_f_ZAIN;
break;
case a_SEEN:
tempc = a_f_SEEN;
break;
case a_SHEEN:
tempc = a_f_SHEEN;
break;
case a_SAD:
tempc = a_f_SAD;
break;
case a_DAD:
tempc = a_f_DAD;
break;
case a_TAH:
tempc = a_f_TAH;
break;
case a_ZAH:
tempc = a_f_ZAH;
break;
case a_AIN:
tempc = a_f_AIN;
break;
case a_GHAIN:
tempc = a_f_GHAIN;
break;
case a_TATWEEL: /* exception */
tempc = cur_c;
break;
case a_FEH:
tempc = a_f_FEH;
break;
case a_QAF:
tempc = a_f_QAF;
break;
case a_KAF:
tempc = a_f_KAF;
break;
case a_LAM:
tempc = a_f_LAM;
break;
case a_MEEM:
tempc = a_f_MEEM;
break;
case a_NOON:
tempc = a_f_NOON;
break;
case a_HEH:
tempc = a_f_HEH;
break;
case a_WAW:
tempc = a_f_WAW;
break;
case a_ALEF_MAKSURA:
tempc = a_f_ALEF_MAKSURA;
break;
case a_YEH:
tempc = a_f_YEH;
break;
default:
tempc = 0;
}
return tempc;
}
/*
* Change shape - from Initial to Medial
*/
static int
chg_c_i2m(int cur_c)
{
int tempc;
switch (cur_c)
{
case a_i_YEH_HAMZA:
tempc = a_m_YEH_HAMZA;
break;
case a_i_BEH:
tempc = a_m_BEH;
break;
case a_i_TEH:
tempc = a_m_TEH;
break;
case a_i_THEH:
tempc = a_m_THEH;
break;
case a_i_JEEM:
tempc = a_m_JEEM;
break;
case a_i_HAH:
tempc = a_m_HAH;
break;
case a_i_KHAH:
tempc = a_m_KHAH;
break;
case a_i_SEEN:
tempc = a_m_SEEN;
break;
case a_i_SHEEN:
tempc = a_m_SHEEN;
break;
case a_i_SAD:
tempc = a_m_SAD;
break;
case a_i_DAD:
tempc = a_m_DAD;
break;
case a_i_TAH:
tempc = a_m_TAH;
break;
case a_i_ZAH:
tempc = a_m_ZAH;
break;
case a_i_AIN:
tempc = a_m_AIN;
break;
case a_i_GHAIN:
tempc = a_m_GHAIN;
break;
case a_i_FEH:
tempc = a_m_FEH;
break;
case a_i_QAF:
tempc = a_m_QAF;
break;
case a_i_KAF:
tempc = a_m_KAF;
break;
case a_i_LAM:
tempc = a_m_LAM;
break;
case a_i_MEEM:
tempc = a_m_MEEM;
break;
case a_i_NOON:
tempc = a_m_NOON;
break;
case a_i_HEH:
tempc = a_m_HEH;
break;
case a_i_YEH:
tempc = a_m_YEH;
break;
default:
tempc = 0;
}
return tempc;
}
/*
* Change shape - from Final to Medial
*/
static int
chg_c_f2m(int cur_c)
{
int tempc;
switch (cur_c)
{
/* NOTE: these encodings are multi-positional, no ?
case a_f_ALEF_MADDA:
case a_f_ALEF_HAMZA_ABOVE:
case a_f_ALEF_HAMZA_BELOW:
*/
case a_f_YEH_HAMZA:
tempc = a_m_YEH_HAMZA;
break;
case a_f_WAW_HAMZA: /* exceptions */
case a_f_ALEF:
case a_f_TEH_MARBUTA:
case a_f_DAL:
case a_f_THAL:
case a_f_REH:
case a_f_ZAIN:
case a_f_WAW:
case a_f_ALEF_MAKSURA:
tempc = cur_c;
break;
case a_f_BEH:
tempc = a_m_BEH;
break;
case a_f_TEH:
tempc = a_m_TEH;
break;
case a_f_THEH:
tempc = a_m_THEH;
break;
case a_f_JEEM:
tempc = a_m_JEEM;
break;
case a_f_HAH:
tempc = a_m_HAH;
break;
case a_f_KHAH:
tempc = a_m_KHAH;
break;
case a_f_SEEN:
tempc = a_m_SEEN;
break;
case a_f_SHEEN:
tempc = a_m_SHEEN;
break;
case a_f_SAD:
tempc = a_m_SAD;
break;
case a_f_DAD:
tempc = a_m_DAD;
break;
case a_f_TAH:
tempc = a_m_TAH;
break;
case a_f_ZAH:
tempc = a_m_ZAH;
break;
case a_f_AIN:
tempc = a_m_AIN;
break;
case a_f_GHAIN:
tempc = a_m_GHAIN;
break;
case a_f_FEH:
tempc = a_m_FEH;
break;
case a_f_QAF:
tempc = a_m_QAF;
break;
case a_f_KAF:
tempc = a_m_KAF;
break;
case a_f_LAM:
tempc = a_m_LAM;
break;
case a_f_MEEM:
tempc = a_m_MEEM;
break;
case a_f_NOON:
tempc = a_m_NOON;
break;
case a_f_HEH:
tempc = a_m_HEH;
break;
case a_f_YEH:
tempc = a_m_YEH;
break;
/* NOTE: these encodings are multi-positional, no ?
case a_f_LAM_ALEF_MADDA_ABOVE:
case a_f_LAM_ALEF_HAMZA_ABOVE:
case a_f_LAM_ALEF_HAMZA_BELOW:
case a_f_LAM_ALEF:
*/
default:
tempc = 0;
}
return tempc;
}
/*
* 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;
}
/*
* Do "half-shaping" on character "c". Return zero if no shaping.
*/
static int
half_shape(int c)
{
if (A_is_a(c))
return chg_c_a2i(c);
if (A_is_valid(c) && A_is_f(c))
return chg_c_f2m(c);
return 0;
}
/*
* 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 shape_c;
int curr_laa;
int prev_laa;
/* Deal only with Arabic character, pass back all others */
if (!A_is_ok(c))
return c;
/* half-shape current and previous character */
shape_c = half_shape(prev_c);
/* Save away current character */
curr_c = c;
curr_laa = A_firstc_laa(c, *c1p);
prev_laa = A_firstc_laa(prev_c, prev_c1);
if (curr_laa)
{
if (A_is_valid(prev_c) && !A_is_f(shape_c)
&& !A_is_s(shape_c) && !prev_laa)
curr_c = chg_c_laa2f(curr_laa);
else
curr_c = chg_c_laa2i(curr_laa);
/* Remove the composing character */
*c1p = 0;
}
else if (!A_is_valid(prev_c) && A_is_valid(next_c))
curr_c = chg_c_a2i(c);
else if (!shape_c || A_is_f(shape_c) || A_is_s(shape_c) || prev_laa)
curr_c = A_is_valid(next_c) ? chg_c_a2i(c) : chg_c_a2s(c);
else if (A_is_valid(next_c))
curr_c = A_is_iso(c) ? chg_c_a2m(c) : chg_c_i2m(c);
else if (A_is_valid(prev_c))
curr_c = chg_c_a2f(c);
else
curr_c = chg_c_a2s(c);
/* Sanity check -- curr_c should, in the future, never be 0.
* We should, in the future, insert a fatal error here. */
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;
}
/*
* A_firstc_laa returns first character of LAA combination if it exists
*/
static int
A_firstc_laa(
int c, /* base character */
int c1) /* first composing character */
{
if (c1 != NUL && c == a_LAM && !A_is_harakat(c1))
return c1;
return 0;
}
/*
* A_is_harakat returns TRUE if 'c' is an Arabic Harakat character
* (harakat/tanween)
*/
static int
A_is_harakat(int c)
{
return (c >= a_FATHATAN && c <= a_SUKUN);
}
/*
* 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 ((c >= a_HAMZA && c <= a_GHAIN)
|| (c >= a_TATWEEL && c <= a_HAMZA_BELOW)
|| c == a_MINI_ALEF);
}
/*
* A_is_formb returns TRUE if 'c' is an Arabic 10646-1 FormB character
* (alphabet/number/punctuation)
*/
static int
A_is_formb(int c)
{
return ((c >= a_s_FATHATAN && c <= a_s_DAMMATAN)
|| c == a_s_KASRATAN
|| (c >= a_s_FATHA && c <= a_f_LAM_ALEF)
|| c == a_BYTE_ORDER_MARK);
}
/*
* 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) || A_is_formb(c));
}
/*
* 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) && !A_is_special(c));
}
/*
* A_is_special returns TRUE if 'c' is not a special Arabic character.
* Specials don't adhere to most of the rules.
*/
static int
A_is_special(int c)
{
return (c == a_HAMZA || c == a_s_HAMZA);
}