private void ReadString()
{
while (Peek() != '"' && !IsAtEnd())
{
// Supports multiline strings
if (Peek() == '\n')
{
m_Line++;
}
Advance();
}
// Unterminated string
if (IsAtEnd())
{
Ori.Error(m_Line, "Unterminated string.");
return;
}
// The closing "
Advance();
// Trim the surrounding quotes
string value = Substring(m_Start + 1, m_Current - 1);
// TODO: If want to support escape sequences, do it here
AddToken(TokenType.String, value);
}
private void ScanToken()
{
char c = Advance();
switch (c)
{
// Braces
case '(': AddToken(TokenType.LeftParen); break;
case ')': AddToken(TokenType.RightParen); break;
case '{': AddToken(TokenType.LeftBrace); break;
case '}': AddToken(TokenType.RightBrace); break;
case '[': AddToken(TokenType.LeftBrace); break;
case ']': AddToken(TokenType.RightBrace); break;
// Syntax
case ',': AddToken(TokenType.Comma); break;
case '.': AddToken(TokenType.Dot); break;
case ';': AddToken(TokenType.Semicolon); break;
// Math
case '-': AddToken(TokenType.Minus); break;
case '+': AddToken(TokenType.Plus); break;
case '*': AddToken(TokenType.Star); break;
case '%': AddToken(TokenType.Modulus); break;
// Boolean
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;
// TODO: Bitwise would be implemented the same as above with AND &&, and OR, etc.
// This would require removing the && and || in the default
case '&':
{
if (Match('&'))
{
AddToken(TokenType.And);
}
else
{
Ori.Error(m_Line, "Bitwise operators are not yet implemented.");
}
break;
}
case '|':
{
if (Match('|'))
{
AddToken(TokenType.Or);
}
else
{
Ori.Error(m_Line, "Bitwise operators are not yet implemented.");
}
break;
}
case '"': ReadString(); break;
case '/':
{
// A comment goes until the end of a line
if (Match('/'))
{
while (Peek() != '\n' && !IsAtEnd())
{
Advance();
}
}
else if (Match('*'))
{
// Keep on reading comment until it reaches */
while (!(Advance() == '*' && Match('/')))
{
;
}
}
else
{
AddToken(TokenType.Slash);
}
break;
}
case ' ':
case '\r':
case '\t':
// Ignore whitespace
break;
case '\n':
m_Line++;
break;
default:
{
if (IsDigit(c))
{
ReadNumber();
}
else if (IsAlpha(c))
{
ReadIdentifier();
}
else
{
Ori.Error(m_Line, "Unexpected character.");
}
break;
}
}
}
