thai/wtt.h(3)

NAME

thai/wtt.h

WTT I/O implementation.

WTT stands for Wing Tuk Tee (in Thai, Runs everywhere). It
was defined by TACTIS (Thai API Consortium/Thai Industrial Stan
dard) in the NECTEC Thai Software Standard Project (1989-1991),
and later endorsed by Thai Industrial Standard Institute (TISI)
as TIS 1566-2541 in 1998.
WTT classifies Thai chracter(TIS-620) into 17 types below.: ITYPE VALUE SHORT_DESCRIPTION CTRL 0 control characters
NON 1 non composible characters
CONS 2 consonants
LV 3 leading vowels
FV1 4 following vowels 1
FV2 5 following vowels 2
FV3 6 following vowels 3
BV1 7 below vowels 1
BV2 8 below vowels 2
BD 9 below diacritics
TONE 10 tonemarks
AD1 11 above diacritics 1
AD2 12 above diacritics 2
AD3 13 above diacritics 3
AV1 14 above vowels 1
AV2 15 above vowels 2
AV3 16 above vowels 3
Functions in thctype.h do basic character classifications
while wtt.h classifies a chracter in detail. Please refer to the
reference.
TACio_op() checks how to compose two given chracters. The
possiblities are Composible (CP), Non-display (XC), Accept (AC),
Reject (RJ) and Strict Reject (SR). The values of CP, XC, AC, RJ
and SR are difined in wtt.h. And their meanings are:
� CP : second character is displayed in the same cell as
the first, also implies an acceptance. � XC : Do nothing. � AC : Display second character in the next cell. � RJ : Discard second character. � SR : Reject second character only in strict mode.

Enumerations
    enum  WTTClass  { CTRL =  0, NON =  1, CONS =  2, LV =  3,

10, AD1 = 11, AD2 = 12, AD3 = 13, AV1 = 14, AV2 = 15, AV3 = 16 }
Classification of characters in TIS620 according to
WTT.
enum WTTOp { CP = 1, XC = 2, AC = 3, RJ = 4, SR = 5 }: Composibility checking tables.
Functions: WTTClass TACchtype (thchar_t c)
WTT character class.; WTTOp TACio_op (thchar_t c1, thchar_t c2)
WTT I/O operation. Enumeration Type Documentation; enum WTTClass
Classification of characters in TIS620 according to WTT.
Enumerator:
CTRL control chars
NON non composibles
CONS consonants
LV leading vowels
FV1 following vowels 1
FV2 following vowels 2
FV3 following vowels 3
BV1 below vowels 1
BV2 below vowels 2
BD below diacritics
TONE tonemarks
AD1 above diacritics 1
AD2 above diacritics 2
AD3 above diacritics 3
AV1 above vowels 1
AV2 above vowels 2
AV3 above vowels 3; enum WTTOp
Composibility checking tables.
Enumerator:
CP COMPOSIBLE - following char is displayed in the

same cell as leading char, also implies ACCEPT
XC Non-display
AC ACCEPT - display the following char in the next

cell
RJ REJECT - discard that following char, ignore it
SR STRICT REJECT - REJECT only if in strict mode

WTTClass TACchtype (thchar_t c): WTT character class.
Parameters:
c : the character; Returns:
WTT character class { CTRL, ..., AV3 }
WTTOp TACio_op (thchar_t c1, thchar_t c2): WTT I/O operation.
Parameters:
c1 : previous character
c2 : next character; Returns:
WTT I/O operation { CP, XC, AC, RJ, SR }