private void HandleString()
{
while (Peek() != '"' && !IsAtEnd)
{
if (Peek() == '\n')
{
_line++;
}
Advance();
}
if (IsAtEnd)
{
// Unterminated string.
SharpLox.Error(_line, "Unterminated string.");
return;
}
// The closing ".
Advance();
var value = _source.Substring(_start + 1, _current - _start - 2);
AddToken(TokenType.String, value);
}
static void Main(string[] args)
{
if (args.Length > 1)
{
Console.WriteLine("Usage: sharplox [script]");
Environment.Exit(64);
}
SharpLox.InitializeInterpreter(args);
}
private void ScanToken()
{
var c = Advance();
switch (c)
{
case '(':
AddToken(TokenType.LeftParen);
break;
case ')':
AddToken(TokenType.RightParen);
break;
case '{':
AddToken(TokenType.LeftBrace);
break;
case '}':
AddToken(TokenType.RightBrace);
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.BangEqual : TokenType.Bang);
break;
case '=':
AddToken(Match('=') ? TokenType.EqualEqual : TokenType.Equal);
break;
case '<':
AddToken(Match('=') ? TokenType.LessEqual : TokenType.Less);
break;
case '>':
AddToken(Match('=') ? TokenType.GreaterEqual : TokenType.Greater);
break;
case '/':
if (Match('/'))
{
// A comment goes until the end of the line.
while (Peek() != '\n' && !IsAtEnd)
{
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))
{
HandleIdentifier();
}
else
{
SharpLox.Error(_line, $"Unexpected character: {c}");
}
break;
}
}
