public void ScanToken()
{
char c = Advance();
switch (c)
{
case '(': AddToken(TokenType.LEFT_PAREN); break;
case ')': AddToken(TokenType.RIGHT_PAREN); break;
case '{': AddToken(TokenType.LEFT_BRACE); break;
case '}': AddToken(TokenType.RIGHT_BRACE); break;
case ',': AddToken(TokenType.COMMA); break;
case '.': AddToken(TokenType.DOT); break;
case '-': AddToken(TokenType.MINUS); break;
case '+': AddToken(TokenType.PLUS); break;
case ';': AddToken(TokenType.SEMICOLON); break;
case '*': AddToken(TokenType.STAR); break;
case '!': AddToken(Match('=') ? TokenType.BANG_EQUAL : TokenType.BANG); break;
case '=': AddToken(Match('=') ? TokenType.EQUAL_EQUAL : TokenType.EQUAL); break;
case '<': AddToken(Match('=') ? TokenType.LESS_EQUAL : TokenType.LESS); break;
case '>': AddToken(Match('=') ? TokenType.GREATER_EQUAL : TokenType.GREATER); break;
case '/':
if (Match('/'))
{
while (Peek() != '\n' && !IsAtEnd())
{
Advance();
}
}
else if (Match('*'))
{
while (!(Peek() != '*' && PeekNext() != '/') && !IsAtEnd())
{
if (Peek() == '\n')
{
line++;
}
Advance();
}
}
else
{
AddToken(TokenType.SLASH);
}
break;
case ' ':
case '\r':
case '\t':
// Ignore whitespace.
break;
case '\n':
line++;
break;
case '"': HandleString(); break;
default:
if (IsDigit(c))
{
HandleNumber();
}
else if (IsAlpha(c))
{
Identifier();
}
else
{
Lox.Error(line, "Unexpected Character.");
}
break;
}
}
private ParserErrorException Error(Token token, string message)
{
Lox.Error(token, message);
return(new ParserErrorException());
}
private ParseError Error(Token token, string message)
{
Lox.Error(token, message);
return(new ParseError());
}
private void ScanToken()
{
char c = Advance();
switch (c)
{
case '(': AddToken(LEFT_PAREN); break;
case ')': AddToken(RIGHT_PAREN); break;
case '{': AddToken(LEFT_BRACE); break;
case '}': AddToken(RIGHT_BRACE); break;
case ',': AddToken(COMMA); break;
case '.': AddToken(DOT); break;
case '-': AddToken(MINUS); break;
case '+': AddToken(PLUS); break;
case ';': AddToken(SEMICOLON); break;
case '*': AddToken(STAR); break;
case '!': AddToken(Match('=') ? BANG_EQUAL : BANG); break;
case '=': AddToken(Match('=') ? EQUAL_EQUAL : EQUAL); break;
case '<': AddToken(Match('=') ? LESS_EQUAL : LESS); break;
case '>': AddToken(Match('=') ? GREATER_EQUAL : GREATER); break;
case '/':
if (Match('/')) //We are inside of a comment discard the whole line
{
while (Peek() != '\n' && !IsAtEnd())
{
Advance();
}
}
else
{
AddToken(SLASH);
}
break;
case '"': ScanString(); break;
case '\n':
_line++;
break;
case ' ':
case '\r':
case '\t':
// Ignore Whitespaces
break;
default:
if (IsDigit(c))
{
ScanNumber();
}
else if (IsAlpha(c))
{
ScanIdentifier();
}
else
{
Lox.Error(_line, "Unexpected character.");
}
break;
}
}