private Token[] Tokenizer(string s)
{
List <Token> list = new List <Token>();
Token pending = null;
for (int i = 0; i < s.Length; i++)
{
char c = s[i];
if (c == ' ')
{
if (pending != null)
{
list.Add(pending);
pending = null;
}
}
else if (c == '+' || c == '-' || c == '/' || c == '*' || c == '(' || c == ')')
{
if (pending != null)
{
list.Add(pending);
pending = null;
}
list.Add(new Token(i));
}
else if (c >= '0' && c <= '9')
{
if (pending != null)
{
pending.Advance();
}
else
{
pending = new Token(i);
}
}
else
{
throw new Exception("Tokenize: Unexpected symbol");
}
}
if (pending != null)
{
list.Add(pending);
}
return(list.ToArray());
}