libthai  0.1.14
Functions
thctype.h File Reference

Thai character classifications. More...

Functions

int th_istis (thchar_t c)
 Is the character a valid TIS-620 code?
int th_isthai (thchar_t c)
 Is the character a Thai character?
int th_iseng (thchar_t c)
 Is the character an English character?
int th_isthcons (thchar_t c)
 Is the character a Thai consonant?
int th_isthvowel (thchar_t c)
 Is the character a Thai vowel?
int th_isthtone (thchar_t c)
 Is the character a Thai tone mark?
int th_isthdiac (thchar_t c)
 Is the character a Thai diacritic?
int th_isthdigit (thchar_t c)
 Is the character a Thai digit?
int th_isthpunct (thchar_t c)
 Is the character a Thai punctuation?
int th_istaillesscons (thchar_t c)
 Is the character a Thai consonant that fits the x-height?
int th_isovershootcons (thchar_t c)
 Is the character a Thai consonant with stem above ascender?
int th_isundershootcons (thchar_t c)
 Is the character a Thai consonant with stem below baseline?
int th_isundersplitcons (thchar_t c)
 Is the character a Thai consonant with split part below baseline?
int th_isldvowel (thchar_t c)
 Is the character a Thai leading vowel?
int th_isflvowel (thchar_t c)
 Is the character a Thai following vowel?
int th_isupvowel (thchar_t c)
 Is the character a Thai upper vowel?
int th_isblvowel (thchar_t c)
 Is the character a Thai below vowel?
int th_chlevel (thchar_t c)
 Position for rendering:
int th_iscombchar (thchar_t c)
 Is the character a combining character?

Detailed Description

Thai character classifications.

The Thai Standard Industrial Standards Institute (TIS) defined the Thai character set for using with computer named TIS-620. This character set is 8-bit encoded including both English and Thai characters. Aliases of TIS-620 are TIS620, TIS620-0, TIS620.2529-1, TIS620.2533-0 and ISO-IR-166.

The followings are the enconding values in hexadecimal, unicode values and their names.

   0x00   <U0000> NULL (NUL)
   0x01   <U0001> START OF HEADING (SOH)
   0x02   <U0002> START OF TEXT (STX)
   0x03   <U0003> END OF TEXT (ETX)
   0x04   <U0004> END OF TRANSMISSION (EOT)
   0x05   <U0005> ENQUIRY (ENQ)
   0x06   <U0006> ACKNOWLEDGE (ACK)
   0x07   <U0007> BELL (BEL)
   0x08   <U0008> BACKSPACE (BS)
   0x09   <U0009> CHARACTER TABULATION (HT)
   0x0A   <U000A> LINE FEED (LF)
   0x0B   <U000B> LINE TABULATION (VT)
   0x0C   <U000C> FORM FEED (FF)
   0x0D   <U000D> CARRIAGE RETURN (CR)
   0x0E   <U000E> SHIFT OUT (SO)
   0x0F   <U000F> SHIFT IN (SI)
   0x10   <U0010> DATALINK ESCAPE (DLE)
   0x11   <U0011> DEVICE CONTROL ONE (DC1)
   0x12   <U0012> DEVICE CONTROL TWO (DC2)
   0x13   <U0013> DEVICE CONTROL THREE (DC3)
   0x14   <U0014> DEVICE CONTROL FOUR (DC4)
   0x15   <U0015> NEGATIVE ACKNOWLEDGE (NAK)
   0x16   <U0016> SYNCHRONOUS IDLE (SYN)
   0x17   <U0017> END OF TRANSMISSION BLOCK (ETB)
   0x18   <U0018> CANCEL (CAN)
   0x19   <U0019> END OF MEDIUM (EM)
   0x1A   <U001A> SUBSTITUTE (SUB)
   0x1B   <U001B> ESCAPE (ESC)
   0x1C   <U001C> FILE SEPARATOR (IS4)
   0x1D   <U001D> GROUP SEPARATOR (IS3)
   0x1E   <U001E> RECORD SEPARATOR (IS2)
   0x1F   <U001F> UNIT SEPARATOR (IS1)
   0x20   <U0020> SPACE
   0x21   <U0021> EXCLAMATION MARK
   0x22   <U0022> QUOTATION MARK
   0x23   <U0023> NUMBER SIGN
   0x24   <U0024> DOLLAR SIGN
   0x25   <U0025> PERCENT SIGN
   0x26   <U0026> AMPERSAND
   0x27   <U0027> APOSTROPHE
   0x28   <U0028> LEFT PARENTHESIS
   0x29   <U0029> RIGHT PARENTHESIS
   0x2A   <U002A> ASTERISK
   0x2B   <U002B> PLUS SIGN
   0x2C   <U002C> COMMA
   0x2D   <U002D> HYPHEN-MINUS
   0x2E   <U002E> FULL STOP
   0x2F   <U002F> SOLIDUS
   0x30   <U0030> DIGIT ZERO
   0x31   <U0031> DIGIT ONE
   0x32   <U0032> DIGIT TWO
   0x33   <U0033> DIGIT THREE
   0x34   <U0034> DIGIT FOUR
   0x35   <U0035> DIGIT FIVE
   0x36   <U0036> DIGIT SIX
   0x37   <U0037> DIGIT SEVEN
   0x38   <U0038> DIGIT EIGHT
   0x39   <U0039> DIGIT NINE
   0x3A   <U003A> COLON
   0x3B   <U003B> SEMICOLON
   0x3C   <U003C> LESS-THAN SIGN
   0x3D   <U003D> EQUALS SIGN
   0x3E   <U003E> GREATER-THAN SIGN
   0x3F   <U003F> QUESTION MARK
   0x40   <U0040> COMMERCIAL AT
   0x41   <U0041> LATIN CAPITAL LETTER A
   0x42   <U0042> LATIN CAPITAL LETTER B
   0x43   <U0043> LATIN CAPITAL LETTER C
   0x44   <U0044> LATIN CAPITAL LETTER D
   0x45   <U0045> LATIN CAPITAL LETTER E
   0x46   <U0046> LATIN CAPITAL LETTER F
   0x47   <U0047> LATIN CAPITAL LETTER G
   0x48   <U0048> LATIN CAPITAL LETTER H
   0x49   <U0049> LATIN CAPITAL LETTER I
   0x4A   <U004A> LATIN CAPITAL LETTER J
   0x4B   <U004B> LATIN CAPITAL LETTER K
   0x4C   <U004C> LATIN CAPITAL LETTER L
   0x4D   <U004D> LATIN CAPITAL LETTER M
   0x4E   <U004E> LATIN CAPITAL LETTER N
   0x4F   <U004F> LATIN CAPITAL LETTER O
   0x50   <U0050> LATIN CAPITAL LETTER P
   0x51   <U0051> LATIN CAPITAL LETTER Q
   0x52   <U0052> LATIN CAPITAL LETTER R
   0x53   <U0053> LATIN CAPITAL LETTER S
   0x54   <U0054> LATIN CAPITAL LETTER T
   0x55   <U0055> LATIN CAPITAL LETTER U
   0x56   <U0056> LATIN CAPITAL LETTER V
   0x57   <U0057> LATIN CAPITAL LETTER W
   0x58   <U0058> LATIN CAPITAL LETTER X
   0x59   <U0059> LATIN CAPITAL LETTER Y
   0x5A   <U005A> LATIN CAPITAL LETTER Z
   0x5B   <U005B> LEFT SQUARE BRACKET
   0x5C   <U005C> REVERSE SOLIDUS
   0x5D   <U005D> RIGHT SQUARE BRACKET
   0x5E   <U005E> CIRCUMFLEX ACCENT
   0x5F   <U005F> LOW LINE
   0x60   <U0060> GRAVE ACCENT
   0x61   <U0061> LATIN SMALL LETTER A
   0x62   <U0062> LATIN SMALL LETTER B
   0x63   <U0063> LATIN SMALL LETTER C
   0x64   <U0064> LATIN SMALL LETTER D
   0x65   <U0065> LATIN SMALL LETTER E
   0x66   <U0066> LATIN SMALL LETTER F
   0x67   <U0067> LATIN SMALL LETTER G
   0x68   <U0068> LATIN SMALL LETTER H
   0x69   <U0069> LATIN SMALL LETTER I
   0x6A   <U006A> LATIN SMALL LETTER J
   0x6B   <U006B> LATIN SMALL LETTER K
   0x6C   <U006C> LATIN SMALL LETTER L
   0x6D   <U006D> LATIN SMALL LETTER M
   0x6E   <U006E> LATIN SMALL LETTER N
   0x6F   <U006F> LATIN SMALL LETTER O
   0x70   <U0070> LATIN SMALL LETTER P
   0x71   <U0071> LATIN SMALL LETTER Q
   0x72   <U0072> LATIN SMALL LETTER R
   0x73   <U0073> LATIN SMALL LETTER S
   0x74   <U0074> LATIN SMALL LETTER T
   0x75   <U0075> LATIN SMALL LETTER U
   0x76   <U0076> LATIN SMALL LETTER V
   0x77   <U0077> LATIN SMALL LETTER W
   0x78   <U0078> LATIN SMALL LETTER X
   0x79   <U0079> LATIN SMALL LETTER Y
   0x7A   <U007A> LATIN SMALL LETTER Z
   0x7B   <U007B> LEFT CURLY BRACKET
   0x7C   <U007C> VERTICAL LINE
   0x7D   <U007D> RIGHT CURLY BRACKET
   0x7E   <U007E> TILDE
   0x7F   <U007F> DELETE (DEL)
   0xA1   <U0E01> THAI CHARACTER KO KAI
   0xA2   <U0E02> THAI CHARACTER KHO KHAI
   0xA3   <U0E03> THAI CHARACTER KHO KHUAT
   0xA4   <U0E04> THAI CHARACTER KHO KHWAI
   0xA5   <U0E05> THAI CHARACTER KHO KHON
   0xA6   <U0E06> THAI CHARACTER KHO RAKHANG
   0xA7   <U0E07> THAI CHARACTER NGO NGU
   0xA8   <U0E08> THAI CHARACTER CHO CHAN
   0xA9   <U0E09> THAI CHARACTER CHO CHING
   0xAA   <U0E0A> THAI CHARACTER CHO CHANG
   0xAB   <U0E0B> THAI CHARACTER SO SO
   0xAC   <U0E0C> THAI CHARACTER CHO CHOE
   0xAD   <U0E0D> THAI CHARACTER YO YING
   0xAE   <U0E0E> THAI CHARACTER DO CHADA
   0xAF   <U0E0F> THAI CHARACTER TO PATAK
   0xB0   <U0E10> THAI CHARACTER THO THAN
   0xB1   <U0E11> THAI CHARACTER THO NANGMONTHO
   0xB2   <U0E12> THAI CHARACTER THO PHUTHAO
   0xB3   <U0E13> THAI CHARACTER NO NEN
   0xB4   <U0E14> THAI CHARACTER DO DEK
   0xB5   <U0E15> THAI CHARACTER TO TAO
   0xB6   <U0E16> THAI CHARACTER THO THUNG
   0xB7   <U0E17> THAI CHARACTER THO THAHAN
   0xB8   <U0E18> THAI CHARACTER THO THONG
   0xB9   <U0E19> THAI CHARACTER NO NU
   0xBA   <U0E1A> THAI CHARACTER BO BAIMAI
   0xBB   <U0E1B> THAI CHARACTER PO PLA
   0xBC   <U0E1C> THAI CHARACTER PHO PHUNG
   0xBD   <U0E1D> THAI CHARACTER FO FA
   0xBE   <U0E1E> THAI CHARACTER PHO PHAN
   0xBF   <U0E1F> THAI CHARACTER FO FAN
   0xC0   <U0E20> THAI CHARACTER PHO SAMPHAO
   0xC1   <U0E21> THAI CHARACTER MO MA
   0xC2   <U0E22> THAI CHARACTER YO YAK
   0xC3   <U0E23> THAI CHARACTER RO RUA
   0xC4   <U0E24> THAI CHARACTER RU
   0xC5   <U0E25> THAI CHARACTER LO LING
   0xC6   <U0E26> THAI CHARACTER LU
   0xC7   <U0E27> THAI CHARACTER WO WAEN
   0xC8   <U0E28> THAI CHARACTER SO SALA
   0xC9   <U0E29> THAI CHARACTER SO RUSI
   0xCA   <U0E2A> THAI CHARACTER SO SUA
   0xCB   <U0E2B> THAI CHARACTER HO HIP
   0xCC   <U0E2C> THAI CHARACTER LO CHULA
   0xCD   <U0E2D> THAI CHARACTER O ANG
   0xCE   <U0E2E> THAI CHARACTER HO NOKHUK
   0xCF   <U0E2F> THAI CHARACTER PAIYANNOI
   0xD0   <U0E30> THAI CHARACTER SARA A
   0xD1   <U0E31> THAI CHARACTER MAI HAN-AKAT
   0xD2   <U0E32> THAI CHARACTER SARA AA
   0xD3   <U0E33> THAI CHARACTER SARA AM
   0xD4   <U0E34> THAI CHARACTER SARA I
   0xD5   <U0E35> THAI CHARACTER SARA II
   0xD6   <U0E36> THAI CHARACTER SARA UE
   0xD7   <U0E37> THAI CHARACTER SARA UEE
   0xD8   <U0E38> THAI CHARACTER SARA U
   0xD9   <U0E39> THAI CHARACTER SARA UU
   0xDA   <U0E3A> THAI CHARACTER PHINTHU
   0xDF   <U0E3F> THAI CHARACTER SYMBOL BAHT
   0xE0   <U0E40> THAI CHARACTER SARA E
   0xE1   <U0E41> THAI CHARACTER SARA AE
   0xE2   <U0E42> THAI CHARACTER SARA O
   0xE3   <U0E43> THAI CHARACTER SARA AI MAIMUAN
   0xE4   <U0E44> THAI CHARACTER SARA AI MAIMALAI
   0xE5   <U0E45> THAI CHARACTER LAKKHANGYAO
   0xE6   <U0E46> THAI CHARACTER MAIYAMOK
   0xE7   <U0E47> THAI CHARACTER MAITAIKHU
   0xE8   <U0E48> THAI CHARACTER MAI EK
   0xE9   <U0E49> THAI CHARACTER MAI THO
   0xEA   <U0E4A> THAI CHARACTER MAI TRI
   0xEB   <U0E4B> THAI CHARACTER MAI CHATTAWA
   0xEC   <U0E4C> THAI CHARACTER THANTHAKHAT
   0xED   <U0E4D> THAI CHARACTER NIKHAHIT
   0xEE   <U0E4E> THAI CHARACTER YAMAKKAN
   0xEF   <U0E4F> THAI CHARACTER FONGMAN
   0xF0   <U0E50> THAI DIGIT ZERO
   0xF1   <U0E51> THAI DIGIT ONE
   0xF2   <U0E52> THAI DIGIT TWO
   0xF3   <U0E53> THAI DIGIT THREE
   0xF4   <U0E54> THAI DIGIT FOUR
   0xF5   <U0E55> THAI DIGIT FIVE
   0xF6   <U0E56> THAI DIGIT SIX
   0xF7   <U0E57> THAI DIGIT SEVEN
   0xF8   <U0E58> THAI DIGIT EIGHT
   0xF9   <U0E59> THAI DIGIT NINE
   0xFA   <U0E5A> THAI CHARACTER ANGKHANKHU
   0xFB   <U0E5B> THAI CHARACTER KHOMUT
   

Thai characters consist of 44 consonants, vowels, tonemarks, diacritics and Thai digits. Thai vowels are divided into 4 groups, Leading Vowels (LV), Following Vowels (FV), Below Vowels (BV) and Above Vowels (AV). There are 4 tonemarks whose position is above a consonant. Diacritics are divided into 2 groups, Above Diacritics (AD) and Below Diacritics (BD).

Libthai has defined 4 levels for the position of a character.

There is an extra level value 3 for certain characters which are usually classified as characters at Above level, but are also allowed to be placed at Top level for some rare cases. Two characters fall in this category, namely MAITAIKHU and NIKHAHIT.

MAITAIKHU can be placed at Top level when writing some minority languages such as Kuy, to shorten some syllables with compound vowels, such as Sara Ia and Sara Uea. NIKHAHIT can be placed at Top level in Pali/Sanskrit words, to represent -ng final sound above SARA I.

The following figure illustrates a Thai word and characters' level.

   ————————— Top(2) 
   ——*——————– Top(2) 
   ——*——————– Top(2) 
   —————————
   ————————— Above(1)
   ——*—————*—- Above(1)
   —****—————*—- Above(1)
   ————————— Above(1)
   —————————
   ————————— Base(0) 
   –*—*—-***—–*–*—- Base(0) 
   -*-*-*-*–*—*—*-*-*—- Base(0) 
   –**-*-*——*—**–*—- Base(0) 
   —**–*—*–*—*—*—- Base(0) 
   —**–*–*-*-*—-*–*—- Base(0) 
   —*—*–**–*—*—*—- Base(0) 
   —*—*–*—*—*—*—- Base(0) 
   —*—*–*****—*****—- Base(0) 
   ————————— Baseline
   ————————— Below(-1)
   ——————-**-*—- Below(-1)
   ——————–***—- Below(-1)
   ————————— Below(-1)
   

A character placed at below, above or top level is also called dead character. It is usually combined with a consonant, after a dead character is typed, the cursor will not be advanced to the next display cell. BV, BD, TONE, AD and AV are classified as dead character.


Function Documentation

int th_chlevel ( thchar_t  c)

Position for rendering:

  • 3 = above/top
  • 2 = top
  • 1 = above
  • 0 = base
  • -1 = below
int th_istis ( thchar_t  c)

Is the character a valid TIS-620 code?

TIS-620 here means US-ASCII plus TIS-620 extension. Character codes in CR area (0x80-0x9f), non-breaking space (0xa0), code gap range (0xdb-0xde and 0xfc-0xff) are excluded.


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