/// <summary>
/// 파싱함수
/// </summary>
/// <param name="equation"></param>
/// <param name="index"></param>
/// <param name="root"></param>
/// <returns></returns>
int Parse(string equation, int index, EquationElement root)
{
while (index < equation.Length)
{
char ch = equation[index];
if (char.IsWhiteSpace(ch)) // 공백무시
{
index++;
continue;
}
if (Operator.IsValidOperator(ch)) // 각 클래스에 정의된 Valid옵션을 토대로 Parse
{
EquationElement n = Add(new Operator(equation, index)); // Add에서 해당 Element의 길이를 구해서 스택에 저장.
index += n.Length; //인덱스를 n의 길이만큼 늘려서 계속 검색
continue;
}
if (Number.IsValidDigit(equation, index))
{
EquationElement n = Add(new Number(equation, index));
index += n.Length;
continue;
}
if (Constant.IsValidDigit(equation, index))
{
EquationElement n = Add(new Constant(equation, index));
index += n.Length;
continue;
}
if (Function.IsValidDigit(equation, index))
{
EquationElement n = Add(new Function(equation, index, root));
index += n.Length;
continue;
}
if (CompareOperator.IsValidOperator(equation))
{
EquationElement n = Add(new CompareOperator(equation));
index += n.Length;
continue;
}
if (Variable.IsValidDigit(equation, index, root))
{
EquationElement n = Add(new Variable(equation, index, root));
index += n.Length;
continue;
}
index++;
if (Term.IsValidDigit(ch)) // 괄호가 또나오면 그 괄호를 풀어야됨.
{
int endindex = FindMatchingEnd(ch, equation, index - 1);
if (endindex > index)
{
int len = endindex - index;
string s = equation.Substring(index, len);
Term g = Add(new Term(s, 0)) as Term;
len = g.Parse(s, 0, root) + 1;
index += len;
continue;
}
throw new ParseException(equation, index - 1, "매칭되는 괄호를 찾을 수 없습니다.");
}
else
{
if (ch == ']' || ch == ')')
{
throw new ParseException(equation, index - 1, " 매칭되는 괄호를 찾을 수 없습니다");
}
}
}
return(index);
}
