Thai Illegal Sequences

[Chookij Vanatham <chookij vanatham eng sun com>]

Hi Robert,

] ] I'll put this on my TODO list for xterm. To confirm, this is for all cases
] ] where
] ] 
] ]   [0E48-0E4B] is followed by [0E31,0E34-0E3A] ?
] ] 
] This is not all the cases.
] I'll be sending them to you tomorrow.
] 
] Chookij V.

There are 2 tables in Wtt.c file.

Table 1: int _TACchclass[256]
is the table to check the type of Thai characters.
There are about 17 types.

Table 2: _TAC_celltype_inputcheck[17][17]
is the table to check if the sequence of Thai characters are valid or not.

#define ChrType(InpChr)		_TACchclass[(unsigned char)(InpChr)]


switch (_TAC_celltype_inputcheck[ChrType(PrevInpChr)]
        	[ChrType(FollInpChr)])
    {
	case 'R':
	 return ILLEGAL_SEQUENCE; <--- this is illegal sequence
	
	case 'S':
    	case 'A':
	case 'C':
	  return LEGAL_SEQUENCE; <--- this is legal sequence

	case 'X': <--- This is the case of control character,
			May be, we don't need to care about this.

    }

This Table is based on TIS620.2533.  Thai unicode is equivalent to TIS620.2533.


Chookij V.

#ifdef  SCCS
static char SccsId[] = "@(#)wtt.h 1.1     97/11/05 SMI";
#endif

#ifndef	_WTT_H
#define	_WTT_H

/* Define TACTIS character classes */
#define		CTRL	0
#define		NON	1
#define		CONS	2
#define		LV	3
#define		FV1	4
#define		FV2	5
#define		FV3	6
#define		BV1	7
#define		BV2	8
#define		BD	9
#define		TONE	10
#define		AD1	11
#define		AD2	12
#define		AD3	13
#define		AV1	14
#define		AV2	15
#define		AV3	16

/* Define type of display level of TACTIS character */
#define		NONDISP	0	/* unprintable character */
#define		BASE	1	/* base character */
#define		ABOVE	2	/* above character */
#define		BELOW	3	/* below character */
#define		TOP	4	/* top character */

/* Define wchar version of the name of TIS620.2533 code */
#define		WC_SARA_AM	L'\323'

#endif	/* _WTT_H */

#ifdef  SCCS
static char SccsId[] = "@(#)Wtt.c 1.2     98/06/29 SMI";
#endif

#include <sys/isa_defs.h>
#include "wtt.h"

int _TACchclass[256] = {
	/*	   0,   1,   2,   3,   4,   5,   6,   7,
		   8,   9,   A,   B,   C,   D,   E,   F  */

	/*00*/	CTRL,CTRL,CTRL,CTRL,CTRL,CTRL,CTRL,CTRL,
		CTRL,CTRL,CTRL,CTRL,CTRL,CTRL,CTRL,CTRL,
	/*10*/	CTRL,CTRL,CTRL,CTRL,CTRL,CTRL,CTRL,CTRL,
		CTRL,CTRL,CTRL,CTRL,CTRL,CTRL,CTRL,CTRL,
	/*20*/	 NON, NON, NON, NON, NON, NON, NON, NON,
		 NON, NON, NON, NON, NON, NON, NON, NON,
	/*30*/	 NON, NON, NON, NON, NON, NON, NON, NON,
		 NON, NON, NON, NON, NON, NON, NON, NON,
	/*40*/	 NON, NON, NON, NON, NON, NON, NON, NON,
		 NON, NON, NON, NON, NON, NON, NON, NON,
	/*50*/	 NON, NON, NON, NON, NON, NON, NON, NON,
		 NON, NON, NON, NON, NON, NON, NON, NON,
	/*60*/	 NON, NON, NON, NON, NON, NON, NON, NON,
		 NON, NON, NON, NON, NON, NON, NON, NON,
	/*70*/	 NON, NON, NON, NON, NON, NON, NON, NON,
		 NON, NON, NON, NON, NON, NON, NON,CTRL,
	/*80*/	CTRL,CTRL,CTRL,CTRL,CTRL,CTRL,CTRL,CTRL,
		CTRL,CTRL,CTRL,CTRL,CTRL,CTRL,CTRL,CTRL,
	/*90*/	CTRL,CTRL,CTRL,CTRL,CTRL,CTRL,CTRL,CTRL,
		CTRL,CTRL,CTRL,CTRL,CTRL,CTRL,CTRL,CTRL,
	/*A0*/	 NON,CONS,CONS,CONS,CONS,CONS,CONS,CONS,
		CONS,CONS,CONS,CONS,CONS,CONS,CONS,CONS,
	/*B0*/	CONS,CONS,CONS,CONS,CONS,CONS,CONS,CONS,
		CONS,CONS,CONS,CONS,CONS,CONS,CONS,CONS,
	/*C0*/	CONS,CONS,CONS,CONS, FV3,CONS, FV3,CONS,
		CONS,CONS,CONS,CONS,CONS,CONS,CONS, NON,
	/*D0*/	 FV1, AV2, FV1, FV1, AV1, AV3, AV2, AV3,
		 BV1, BV2,  BD, NON, NON, NON, NON, NON,
	/*E0*/	  LV,  LV,  LV,  LV,  LV, FV2, NON, AD2,
		TONE,TONE,TONE,TONE, AD1, AD1, AD3, NON,
	/*F0*/	 NON, NON, NON, NON, NON, NON, NON, NON,
		 NON, NON, NON, NON, NON, NON, NON,CTRL
};

/* Table for Thai Cell Manipulation */
char _TAC_celltype_inputcheck[17][17] = {
	/* Cn */ /*	 0,  1,  2,  3,  4,  5,  6,  7,
			 8,  9,  A,  B,  C,  D,  E,  F	    */
	/* Cn-1 00 */	'X', 'A', 'A', 'A', 'A', 'A', 'A', 'R',
			'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R',
	     /* 10 */	'X', 'A', 'A', 'A', 'S', 'S', 'A', 'R',
			'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R',
	     /* 20 */	'X', 'A', 'A', 'A', 'A', 'S', 'A', 'C',
			'C', 'C', 'C', 'C', 'C', 'C', 'C', 'C', 'C',
	     /*	30 */	'X', 'S', 'A', 'S', 'S', 'S', 'S', 'R',
			'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R',
	     /* 40 */	'X', 'S', 'A', 'A', 'S', 'S', 'A', 'R',
			'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R',
	     /* 50 */	'X', 'A', 'A', 'A', 'A', 'S', 'A', 'R',
			'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R',
	     /* 60 */	'X', 'A', 'A', 'A', 'S', 'A', 'S', 'R',
			'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R',
	     /* 70 */	'X', 'A', 'A', 'A', 'S', 'S', 'A', 'R',
			'R', 'R', 'C', 'C', 'R', 'R', 'R', 'R', 'R',
	     /* 80 */	'X', 'A', 'A', 'A', 'S', 'S', 'A', 'R',
			'R', 'R', 'C', 'R', 'R', 'R', 'R', 'R', 'R',
	     /* 90 */	'X', 'A', 'A', 'A', 'S', 'S', 'A', 'R',
			'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R',
	     /* A0 */	'X', 'A', 'A', 'A', 'A', 'A', 'A', 'R',
			'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R',
	     /* B0 */	'X', 'A', 'A', 'A', 'S', 'S', 'A', 'R',
			'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R',
	     /* C0 */	'X', 'A', 'A', 'A', 'S', 'S', 'A', 'R',
			'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R',
	     /* D0 */	'X', 'A', 'A', 'A', 'S', 'S', 'A', 'R',
			'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R',
	     /* E0 */	'X', 'A', 'A', 'A', 'S', 'S', 'A', 'R',
			'R', 'R', 'C', 'C', 'R', 'R', 'R', 'R', 'R',
	     /* F0 */	'X', 'A', 'A', 'A', 'S', 'S', 'A', 'R',
			'R', 'R', 'C', 'R', 'R', 'R', 'R', 'R', 'R',
			'X', 'A', 'A', 'A', 'S', 'S', 'A', 'R',
			'R', 'R', 'C', 'R', 'C', 'R', 'R', 'R', 'R'
};