static void Main(string[] args)
{
if (args.Length > 1)
{
Console.WriteLine("Usage : Slan [script]");
System.Environment.Exit(0);
}
else if (args.Length == 1)
{
Slan.runFile(args[0]);
}
else
{
Slan.runPrompt();
}
}
private void itsString()
{
while (peek() != '"' && !isAtEnd())
{
if (peek() == '\n')
{
line++;
}
advance();
}
if (isAtEnd())
{
Slan.error(line, "Unterminated string.");
return;
}
advance();
String value = source.Substring(start + 1, (current - start) - 1);
addToken(TokenType.STRING, value);
}
private 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
{
addToken(TokenType.SLASH);
}
break;
case ' ':
case '\r':
case '\t':
break;
case '\n':
line++;
break;
case '"': itsString(); break;
case 'o': if (peek() == 'r')
{
addToken(TokenType.OR);
}
break;
default:
if (isDigit(c))
{
number();
}
else if (isAlpha(c))
{
identifier();
}
else
{
Slan.error(line, "Unexpected character.");
}
break;
}
}
