public static StringLiteralToken ParseToken(string exp, ref int pos)
{
pos++;
StringBuilder builder = new StringBuilder();
int posOfAspas = exp.IndexOf('\'', pos);
if (posOfAspas == -1)
{
throw new SyntaxErrorException("Sequência de caracteres não terminada");
}
StringLiteralToken result = new StringLiteralToken {
Value = exp.Substring(pos, posOfAspas - pos)
};
pos = posOfAspas + 1;
return(result);
}
public IToken GetNextToken()
{
if (tokens >= maxTokens)
{
throw new ExpressionException("Número máximo de tokens excedido.");
}
tokens++;
if (pos == expString.Length)
{
return(new EndToken());
}
SkipWhiteSpaces(expString, ref pos);
if (char.IsDigit(expString[pos]))
{
return(NumberLiteralToken.ParseToken(expString, ref pos));
}
else if (char.IsLetter(expString[pos]))
{
IdentifierToken itoken = IdentifierToken.ParseToken(expString, ref pos);
switch (itoken.IdentifierName)
{
case "e":
return(new EToken());
case "ou":
return(new OuToken());
case "verdadeiro":
return(new BooleanLiteralToken(true));
case "falso":
return(new BooleanLiteralToken(false));
default:
return(itoken);
}
}
else if (Regex.IsMatch(expString.Substring(pos, 1), OPERATORS))
{
if (expString[pos] == '=' && expString[pos + 1] == '>')
{
pos += 2;
return(new LambdaInvokeToken());
}
return(OperatorToken.ParseToken(expString, ref pos));
}
else if (expString[pos] == '(')
{
pos++;
return(new OpenParenthesisToken());
}
else if (expString[pos] == ')')
{
pos++;
return(new CloseParenthesisToken());
}
else if (expString[pos] == ',')
{
pos++;
return(new CommaToken());
}
else if (expString[pos] == '.')
{
pos++;
return(new DotToken());
}
else if (expString[pos] == '\'')
{
return(StringLiteralToken.ParseToken(expString, ref pos));
}
else if (expString[pos] == ENDEXPRESSION)
{
return(new EndToken());
}
else
{
throw new SyntaxErrorException("Invalid token: " + expString[pos]);
}
}