public SyntaxToken Lex()
{
_start = _position;
_kind = SyntaxKind.BadToken;
_value = null;
switch (Current)
{
case '\0':
_kind = SyntaxKind.EndOfFileToken;
break;
case '+':
_kind = SyntaxKind.PlusToken;
_position++;
break;
case '-':
_kind = SyntaxKind.MinusToken;
_position++;
break;
case '*':
_kind = SyntaxKind.StarToken;
_position++;
break;
case '/':
_kind = SyntaxKind.SlashToken;
_position++;
break;
case '(':
_kind = SyntaxKind.OpenParenthesisToken;
_position++;
break;
case ')':
_kind = SyntaxKind.CloseParenthesisToken;
_position++;
break;
case '{':
_kind = SyntaxKind.OpenBraceToken;
_position++;
break;
case '}':
_kind = SyntaxKind.CloseBraceToken;
_position++;
break;
case ':':
_kind = SyntaxKind.ColonToken;
_position++;
break;
case ',':
_kind = SyntaxKind.CommaToken;
_position++;
break;
case '~':
_kind = SyntaxKind.TildeToken;
_position++;
break;
case '^':
_kind = SyntaxKind.HatToken;
_position++;
break;
case '&':
_position++;
if (Current != '&')
{
_kind = SyntaxKind.AmpersandToken;
}
else
{
_kind = SyntaxKind.AmpersandAmpersandToken;
_position++;
}
break;
case '|':
_position++;
if (Current != '|')
{
_kind = SyntaxKind.PipeToken;
}
else
{
_kind = SyntaxKind.PipePipeToken;
_position++;
}
break;
case '=':
_position++;
if (Current != '=')
{
_kind = SyntaxKind.EqualsToken;
}
else
{
_kind = SyntaxKind.EqualsEqualsToken;
_position++;
}
break;
case '!':
_position++;
if (Current != '=')
{
_kind = SyntaxKind.BangToken;
}
else
{
_kind = SyntaxKind.BangEqualsToken;
_position++;
}
break;
case '<':
_position++;
if (Current != '=')
{
_kind = SyntaxKind.LessToken;
}
else
{
_kind = SyntaxKind.LessOrEqualsToken;
_position++;
}
break;
case '>':
_position++;
if (Current != '=')
{
_kind = SyntaxKind.GreaterToken;
}
else
{
_kind = SyntaxKind.GreaterOrEqualsToken;
_position++;
}
break;
case '"':
ReadString();
break;
case '0':
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
case '9':
ReadNumber();
break;
case ' ':
case '\t':
case '\n':
case '\r':
ReadWhiteSpace();
break;
default:
if (char.IsLetter(Current))
{
ReadIdentifierOrKeyword();
}
else if (char.IsWhiteSpace(Current))
{
ReadWhiteSpace();
}
else
{
_diagnostics.ReportBadCharacter(_position, Current);
_position++;
}
break;
}
var length = _position - _start;
var text = SyntaxFacts.GetText(_kind);
if (text == null)
{
text = _text.ToString(_start, length);
}
return(new SyntaxToken(_kind, _start, text, _value));
}