/// <summary>
/// Checks if LexerToken is a reserved word
/// </summary>
/// <param name="token">Token to Check</param>
/// <returns>true = reserved word</returns>
private static bool IsReservedWord(LexerToken token)
{
foreach (string word in reservedWords)
{
if (word == token.Token)
{
return(true);
}
}
return(false);
}
public static List <TokenBase> Lex(this Compiler compiler)
{
List <LexerToken> stringToken = SplitSourceCode(compiler);
List <TokenBase> token = new List <TokenBase>();
for (int i = 0; i < stringToken.Count; i++)
{
LexerToken sToken = stringToken[i];
if (IsReservedWord(sToken))
{
token.Add(new ReservedWordToken(sToken.Token, sToken.LineNumber));
}
else if (IsOperator(sToken.Token[0]))
{
token.Add(new OperatorToken(sToken.Token, sToken.LineNumber));
}
else if (IsCharDigit(sToken.Token[0]))
{
if (stringToken.Count > i + 2)
{
// if digit + "." + digit, we have a double number
if (stringToken[i + 1].Token == "." && IsCharDigit(stringToken[i + 2].Token[0]))
{
sToken.Token += stringToken[i + 1].Token + stringToken[i + 2].Token;
i += 2;
}
}
ValidateNumber(sToken);
token.Add(new NumberToken(sToken.Token, sToken.LineNumber));
}
else if (sToken.Token[0] == '"')
{
token.Add(new StringToken(sToken.Token.Substring(1, sToken.Token.Length - 2), sToken.LineNumber));
}
else if (IsSpecialToken(sToken.Token[0]))
{
token.Add(new SpecialToken(sToken.Token, sToken.LineNumber));
}
else
{
ValidateIdentifier(sToken);
token.Add(new IdentifierToken(sToken.Token, sToken.LineNumber));
}
}
return(token);
}
/// <summary>
/// Checks if token is a valid Number else an Exception is raised
/// </summary>
/// <param name="token">Token to Check</param>
private static void ValidateIdentifier(LexerToken token)
{
string lowerToken = token.Token.ToLower();
for (int i = 0; i < lowerToken.Length; i++)
{
if (lowerToken[i] != '_' && lowerToken[i] != 'a' && lowerToken[i] != 'b' && lowerToken[i] != 'c' &&
lowerToken[i] != 'd' && lowerToken[i] != 'e' && lowerToken[i] != 'f' && lowerToken[i] != 'g' &&
lowerToken[i] != 'h' && lowerToken[i] != 'i' && lowerToken[i] != 'j' && lowerToken[i] != 'k' &&
lowerToken[i] != 'l' && lowerToken[i] != 'm' && lowerToken[i] != 'n' && lowerToken[i] != 'o' &&
lowerToken[i] != 'p' && lowerToken[i] != 'q' && lowerToken[i] != 'r' && lowerToken[i] != 's' &&
lowerToken[i] != 't' && lowerToken[i] != 'u' && lowerToken[i] != 'v' && lowerToken[i] != 'w' &&
lowerToken[i] != 'x' && lowerToken[i] != 'y' && lowerToken[i] != 'z' && !IsCharDigit(lowerToken[i]))
{
throw new LexerException(string.Format("Identifier {0} has an invalid Name.", token.Token), token.LineNumber);
}
}
}
/// <summary>
/// Checks if token is a valid Number else an Exception is raised
/// </summary>
/// <param name="token">Token to Check</param>
private static void ValidateNumber(LexerToken token)
{
bool dot = false;
for (int i = 0; i < token.Token.Length; i++)
{
if (token.Token[i] == '.')
{
if (dot)
{
throw new LexerException(string.Format("Invalid Number {0}.", token.Token), token.LineNumber);
}
else
{
dot = true;
}
}
else if (!IsCharDigit(token.Token[i]))
{
throw new LexerException(string.Format("Invalid Number {0}.", token.Token), token.LineNumber);
}
}
}
