Method GetBuiltInVar

source/script.cpp:7331–7356

VarEntry *Script::GetBuiltInVar(LPCTSTR aVarName)
{
	// This array approach saves about 9KB on code size over the old approach
	// of a series of if's and _tcscmp calls, and performs about the same.
	// The "A_" prefix is omitted from each name string to reduce code size.
	if ((aVarName[0] == 'A' || aVarName[0] == 'a') && aVarName[1] == '_')
		aVarName += 2;
	else
		return nullptr;
	// Using binary search vs. linear search performs a bit better (notably for
	// rare/contrived cases like A_x%index%) and doesn't affect code size much.
	int left, right, mid, result;
	for (left = 0, right = _countof(g_BIV_A) - 1; left <= right;)
	{
		mid = (left + right) / 2;
		result = _tcsicmp(aVarName, g_BIV_A[mid].name);
		if (result > 0)
			left = mid + 1;
		else if (result < 0)
			right = mid - 1;
		else // Match found.
			return &g_BIV_A[mid];
	}
	// Since above didn't return:
	return nullptr;
}