def number_of_leading_spaces(s)
		n=0; i=0;
		while i < s.size 
			c = s[i,1]
			if c == ' '
				i+=1; n+=1;
			elsif c == "\t"
				i+=1; n+=TabSize;
			else
				break
			end
		end
		n
	end
def number_of_leading_spaces(s)
		n=0; i=0;
		while i < s.size 
			c = s[i,1]
			if c == ' '
				i+=1; n+=1;
			elsif c == "\t"
				i+=1; n+=TabSize;
			else
				break
			end
		end
		n
	end
Returns the number of leading spaces, considering that
 a tab counts as `TabSize` spaces.