/// <summary>
/// Lex a comment.
/// </summary>
private Token LexComment()
{
Contracts.Assert(ChCur == '/');
int ichErr = _cursor.IchCur;
switch (ChPeek(1))
{
default:
return(LexPunc());
case '/':
// Single line comment.
ChNext();
_sb.Length = 0;
_sb.Append("//");
for (; ;)
{
if (LexCharUtils.IsLineTerm(ChNext()) || Eof)
{
return(new CommentToken(GetSpan(), _sb.ToString(), 0));
}
_sb.Append(ChCur);
}
case '*':
/* block comment */
ChNext();
_sb.Length = 0;
_sb.Append("/*");
ChNext();
int lines = 0;
for (; ;)
{
if (Eof)
{
ReportError(ichErr, _cursor.IchCur, ErrId.UnterminatedComment);
break;
}
char ch = ChCur;
if (LexCharUtils.IsLineTerm(ch))
{
ch = LexLineTerm(_sb);
lines++;
}
else
{
ChNext();
}
_sb.Append(ch);
if (ch == '*' && ChCur == '/')
{
_sb.Append('/');
ChNext();
break;
}
}
// We support comment keywords.
KeyWordTable.KeyWordKind kind;
NormStr nstr = _lex._pool.Add(_sb);
if (_lex._kwt.IsKeyWord(nstr, out kind))
{
return(KeyToken.CreateKeyWord(GetSpan(), nstr.ToString(), kind.Kind, kind.IsContextKeyWord));
}
return(new CommentToken(GetSpan(), _sb.ToString(), lines));
}
}
/// <summary>
/// Lex a string or character literal.
/// </summary>
private Token LexStrLit()
{
char chQuote;
_sb.Length = 0;
if (ChCur == '@')
{
chQuote = '"';
ChNext();
Contracts.Assert(ChCur == '"');
ChNext();
for (; ;)
{
char ch = ChCur;
if (ch == '"')
{
ChNext();
if (ChCur != '"')
{
break;
}
ChNext();
}
else if (LexCharUtils.IsLineTerm(ch))
{
ch = LexLineTerm(_sb);
}
else if (Eof)
{
ReportError(ErrId.UnterminatedString);
break;
}
else
{
ChNext();
}
_sb.Append(ch);
}
}
else
{
Contracts.Assert(ChCur == '"' || ChCur == '\'');
chQuote = ChCur;
ChNext();
for (; ;)
{
char ch = ChCur;
if (ch == chQuote || Eof || LexCharUtils.IsLineTerm(ch))
{
break;
}
if (ch == '\\')
{
uint u;
if (!FLexEscChar(false, out u))
{
continue;
}
if (u < 0x10000)
{
ch = (char)u;
}
else
{
char chT;
if (!ConvertToSurrogatePair(u, out chT, out ch))
{
continue;
}
_sb.Append(chT);
}
}
else
{
ChNext();
}
_sb.Append(ch);
}
if (ChCur != chQuote)
{
ReportError(ErrId.NewlineInConst);
}
else
{
ChNext();
}
}
if (chQuote == '"')
{
return(new StrLitToken(GetSpan(), _sb.ToString()));
}
if (_sb.Length != 1)
{
ReportError(_sb.Length == 0 ? ErrId.CharConstEmpty : ErrId.CharConstTooLong);
}
return(new CharLitToken(GetSpan(), _sb.Length > 0 ? _sb[0] : '\0'));
}
