private Token NextOperator(char ch)
{
// TODO improve/fix algorithm, multicharacter operators
string value = ch.ToString();
int ich = this.NextChar();
if (ich != -1)
{
string value2 = value + (char)ich;
if (operators.Contains(value2))
return new Token(value2, TokenType.Operator);
this.PushChar(ich);
}
return new Token(value, TokenType.Operator);
}