/* Low-level matching commands code fragment

  The contract here is:

	all commands move forward through the buffer
	
	failure to move forward indicates failure of the tag
	
	moving forward indicates success of the tag
	
	errors may be indicated if encountered in childReturnCode and the error* variables
	
	only childPosition should be updated otherwise

*/
TE_CHAR *m = TE_STRING_AS_STRING(match);
if (m == NULL) {
	childReturnCode = ERROR_CODE;
	errorType = PyExc_TypeError;
	errorMessage = PyString_FromFormat(
		 "Low-level command (%i) argument in entry %i couldn't be converted to a string object, is a %.50s",
		 command,
		 index,
		 textobj->ob_type->tp_name

	);
} else {

switch (command) {

	case MATCH_ALLIN:

		{
			register int ml = TE_STRING_GET_SIZE(match);
			register TE_CHAR *tx = &text[childPosition];

			DPRINTF("\nAllIn :\n"
				" looking for   = '%.40s'\n"
				" in string     = '%.40s'\n",m,tx);

			if (ml > 1) {
				for (; childPosition < sliceright; tx++, childPosition++) {
					register int j;
					register TE_CHAR *mj = m;
					register TE_CHAR ctx = *tx;
					for (j=0; j < ml && ctx != *mj; mj++, j++) ;
					if (j == ml) break;
				}
			} else if (ml == 1) {
				/* one char only: use faster variant: */
				for (; childPosition < sliceright && *tx == *m; tx++, childPosition++) ;
			}
			break;
		}

	case MATCH_ALLNOTIN:

		{
			register int ml = TE_STRING_GET_SIZE(match);
			register TE_CHAR *tx = &text[childPosition];

			DPRINTF("\nAllNotIn :\n"
				" looking for   = '%.40s'\n"
				" not in string = '%.40s'\n",m,tx);

			if (ml != 1) {
				for (; childPosition < sliceright; tx++, childPosition++) {
					register int j;
					register TE_CHAR *mj = m;
					register TE_CHAR ctx = *tx;
					for (j=0; j < ml && ctx != *mj; mj++, j++) ;
					if (j != ml) break;
				}
			} else {
				/* one char only: use faster variant: */
				for (; childPosition < sliceright && *tx != *m; tx++, childPosition++) ;
			}
			break;
		}

	case MATCH_IS: 
		
		{
			DPRINTF("\nIs :\n"
				" looking for   = '%.40s'\n"
				" in string     = '%.40s'\n",m,text+childPosition);

			if (childPosition < sliceright && *(&text[childPosition]) == *m) {
				childPosition++;
			}
			break;
		}

	case MATCH_ISIN:

	{
		register int ml = TE_STRING_GET_SIZE(match);
		register TE_CHAR ctx = text[childPosition];

		DPRINTF("\nIsIn :\n"
			" looking for   = '%.40s'\n"
			" in string     = '%.40s'\n",m,text+childPosition);

		if (ml > 0 && childPosition < sliceright) {
		register int j;
		register TE_CHAR *mj = m;
		for (j=0; j < ml && ctx != *mj; mj++, j++) ;
		if (j != ml) childPosition++;
		}

		break;
	}

	case MATCH_ISNOTIN:

	{
		register int ml = TE_STRING_GET_SIZE(match);
		register TE_CHAR ctx = text[childPosition];

		DPRINTF("\nIsNotIn :\n"
			" looking for   = '%.40s'\n"
			" not in string = '%.40s'\n",m,text+childPosition);

		if (ml > 0 && childPosition < sliceright) {
		register int j;
		register TE_CHAR *mj = m;
		for (j=0; j < ml && ctx != *mj; mj++, j++) ;
		if (j == ml) childPosition++;
		}
		else
		childPosition++;

		break;
	}

	case MATCH_WORD:

	{
		int ml1 = TE_STRING_GET_SIZE(match) - 1;
		register TE_CHAR *tx = &text[childPosition + ml1];
		register int j = ml1;
		register TE_CHAR *mj = &m[j];

		DPRINTF("\nWord :\n"
			" looking for   = '%.40s'\n"
			" in string     = '%.40s'\n",m,&text[childPosition]);

		if (childPosition+ml1 >= sliceright) break;
		
		/* compare from right to left */
		for (; j >= 0 && *tx == *mj;
		 tx--, mj--, j--) ;

		if (j >= 0) /* not matched */
		childPosition = startPosition; /* reset */
		else
		childPosition += ml1 + 1;
		break;
	}

	case MATCH_WORDSTART:
	case MATCH_WORDEND:

	{
		int ml1 = TE_STRING_GET_SIZE(match) - 1;

		if (ml1 >= 0) {
		register TE_CHAR *tx = &text[childPosition];
			
		DPRINTF("\nWordStart/End :\n"
			" looking for   = '%.40s'\n"
			" in string     = '%.40s'\n",m,tx);

		/* Brute-force method; from right to left */
		for (;;) {
			register int j = ml1;
			register TE_CHAR *mj = &m[j];

			if (childPosition+j >= sliceright) {
			/* reached eof: no match, rewind */
			childPosition = startPosition;
			break;
			}

			/* scan from right to left */
			for (tx += j; j >= 0 && *tx == *mj; 
			 tx--, mj--, j--) ;
			/*
			DPRINTF("match text[%i+%i]: %c == %c\n",
					childPosition,j,*tx,*mj);
			*/

			if (j < 0) {
			/* found */
			if (command == MATCH_WORDEND) childPosition += ml1 + 1;
			break;
			}
			/* not found: rewind and advance one char */
			tx -= j - 1;
			childPosition++;
		}
		}

		break;
	}

#if (TE_TABLETYPE == MXTAGTABLE_STRINGTYPE)

	/* Note: These two only work for 8-bit set strings. */
	case MATCH_ALLINSET:

	{
		register TE_CHAR *tx = &text[childPosition];
		unsigned char *m = PyString_AS_STRING(match);

		DPRINTF("\nAllInSet :\n"
			" looking for   = set at 0x%lx\n"
			" in string     = '%.40s'\n",(long)match,tx);

		for (;
		 childPosition < sliceright &&
		 (m[((unsigned char)*tx) >> 3] & 
		  (1 << (*tx & 7))) > 0;
		 tx++, childPosition++) ;

		break;
	}

	case MATCH_ISINSET:

	{
		register TE_CHAR *tx = &text[childPosition];
		unsigned char *m = PyString_AS_STRING(match);

		DPRINTF("\nIsInSet :\n"
			" looking for   = set at 0x%lx\n"
			" in string     = '%.40s'\n",(long)match,tx);

		if (childPosition < sliceright &&
		(m[((unsigned char)*tx) >> 3] & 
		 (1 << (*tx & 7))) > 0)
		childPosition++;

		break;
	}

#endif

	case MATCH_ALLINCHARSET:

	{
		int matching;

		DPRINTF("\nAllInCharSet :\n"
			" looking for   = CharSet at 0x%lx\n"
			" in string     = '%.40s'\n",
			(long)match, &text[childPosition]);
		
		matching = mxCharSet_Match(match,
					   textobj,
					   childPosition,
					   sliceright,
					   1);
		if (matching < 0) {
			childReturnCode = ERROR_CODE;
			errorType = PyExc_SystemError;
			errorMessage = PyString_FromFormat(
				 "Character set match returned value < 0 (%i): probable bug in text processing engine",
				 matching
			);
		} else {
			childPosition += matching;
		}
		break;
	}

	case MATCH_ISINCHARSET:

		{
			int test;

			DPRINTF("\nIsInCharSet :\n"
				" looking for   = CharSet at 0x%lx\n"
				" in string     = '%.40s'\n",
				(long)match, &text[childPosition]);

#if (TE_TABLETYPE == MXTAGTABLE_STRINGTYPE)
			test = mxCharSet_ContainsChar(match, text[childPosition]);
#else
			test = mxCharSet_ContainsUnicodeChar(match, text[childPosition]);
#endif
			if (test < 0) {
				childReturnCode = ERROR_CODE;
				errorType = PyExc_SystemError;
				errorMessage = PyString_FromFormat(
					 "Character set match returned value < 0 (%i): probable bug in text processing engine",
					 test
				);
			} else if (test) {
				childPosition++;
			}
			break;
		}
	default:
		{
			childReturnCode = ERROR_CODE;
			errorType = PyExc_ValueError;
			errorMessage = PyString_FromFormat(
				 "Unrecognised Low-Level command code %i, maximum low-level code is %i",
				 command,
				 MATCH_MAX_LOWLEVEL
			);
		}
/* end of the switch, this child is finished */
}
} /* end of the wrapping if-check */

/* simple determination for these commands (hence calling them low-level) */
if (childReturnCode == NULL_CODE) {
	if (childPosition > childStart) {
		childReturnCode = SUCCESS_CODE;
	} else {
		childReturnCode = FAILURE_CODE;
	}
}