Method actualMerge

src/jrd/Collation.cpp:870–973

Merge the matching pattern and control strings to give a cannonical matching pattern. Return the length of the combined string. What this routine does is to take the language template, strip off the prefix and put it in the output string, then parse the definitions into an array of character pointers. The index array is the defined character. The routine then takes the actual match pattern an

	// highest character defined (also max_op).  Believe it or not, that part
	// is not a bug.
	static ULONG actualMerge(/*MemoryPool& pool,*/ Jrd::TextType* obj,
		const CharType* match, SLONG match_bytes,
		const CharType* control, SLONG control_bytes,
		CharType* combined) //, SLONG combined_bytes)
	{
		fb_assert(match != NULL);
		fb_assert(control != NULL);
		fb_assert(combined != NULL);

		fb_assert((match_bytes % sizeof(CharType)) == 0);
		fb_assert((control_bytes % sizeof(CharType)) == 0);
		fb_assert(obj->getCanonicalWidth() == sizeof(CharType));

		const CharType* const end_match = match + (match_bytes / sizeof(CharType));
		const CharType* const end_control = control + (control_bytes / sizeof(CharType));

		CharType max_op = 0;
		CharType* comb = combined;
		CharType* vector[256];
		CharType** v = vector;
		CharType temp[256];
		CharType* t = temp;

		// Parse control string into substitution strings and initializing string

		while (control < end_control)
		{
			CharType c = *control++;
			if (*control == *(CharType*) obj->getCanonicalChar(CHAR_GDML_SUBSTITUTE))
			{
				// Note: don't allow substitution characters larger than vector
				CharType** const end_vector = vector + (((int) c < FB_NELEM(vector)) ? c : 0);
				while (v <= end_vector)
					*v++ = 0;
				*end_vector = t;
				++control;
				while (control < end_control)
				{
					c = *control++;
					if ((t > temp && t[-1] == *(CharType*) obj->getCanonicalChar(CHAR_GDML_QUOTE)) ||
						((c != *(CharType*) obj->getCanonicalChar(CHAR_GDML_COMMA)) &&
							(c != *(CharType*) obj->getCanonicalChar(CHAR_GDML_RPAREN))))
					{
						*t++ = c;
					}
					else
						break;
				}
				*t++ = 0;
			}
			else if (c == *(CharType*) obj->getCanonicalChar(CHAR_GDML_QUOTE) && control < end_control)
				*comb++ = *control++;
			else if (c == *(CharType*) obj->getCanonicalChar(CHAR_GDML_RPAREN))
				break;
			else if (c != *(CharType*) obj->getCanonicalChar(CHAR_GDML_LPAREN))
				*comb++ = c;
		}