private void SkipNewline()
{
char c = Code.GetChar(Index++);
if (CharUtils.IsNewLine(c))
{
if (c == '\r' && Code.GetChar(Index) == '\n')
{
++Index;
}
++CurrentLine;
CurrentLineStart = Index;
}
}
private Token NextStringLiteral()
{
bool err = true;
int start = Index++;
var str = GetStringBuilder();
while (!IsEof())
{
char c = Code.GetChar(Index);
if (c == '"')
{
c = Code.GetChar(++Index);
if (c == '"')
{
++Index;
str.Append(c);
}
else
{
err = false;
break;
}
}
else if (CharUtils.IsNewLine(c))
{
break;
}
else
{
++Index;
str.Append(c);
}
}
if (err)
{
throw VBSyntaxError(VBSyntaxErrorCode.UnterminatedStringConstant);
}
return(new StringLiteralToken
{
Start = start,
End = Index - 1,
LineNumber = CurrentLine,
LineStart = CurrentLineStart,
Value = str.ToString(),
});
}
private Token NextLineTermination()
{
int start = Index;
int line = CurrentLine;
bool isColon = false;
while (!IsEof())
{
char c = Code.GetChar(Index);
if (CharUtils.IsLineTerminator(c))
{
if (c == '\r' && Code.GetChar(Index + 1) == '\n')
{
++Index;
}
++Index;
isColon |= (c == ':');
if (c != ':')
{
++CurrentLine;
CurrentLineStart = Index;
}
}
else
{
break;
}
SkipWhitespaces();
}
Token token = isColon && line == CurrentLine
? new ColonLineTerminationToken()
: new LineTerminationToken();
token.Start = start;
token.End = Index;
token.LineNumber = CurrentLine - 1;
token.LineStart = CurrentLineStart;
return(token);
}
private string GetIdentifierName()
{
int start = Index;
while (!IsEof())
{
char c = Code.GetChar(Index);
if (CharUtils.IsIdentifier(c))
{
++Index;
}
else
{
break;
}
}
return(Code.Slice(start, Index));
}
private LiteralToken NextHexIntLiteral()
{
int start = Index;
Index += 2;
string str = GetHexStr();
char c = Code.GetChar(Index);
if (CharUtils.IsIdentifierStart(c))
{
throw VBSyntaxError(VBSyntaxErrorCode.ExpectedEndOfStatement);
}
var result = ParseInteger(str, 16);
result.Start = start;
return(result);
}
public void SkipWhitespaces()
{
void SkipWSOnly()
{
char c = Code.GetChar(Index);
while (CharUtils.IsWhiteSpace(c))
{
c = Code.GetChar(++Index);
}
}
while (!IsEof())
{
SkipWSOnly();
char c = Code.GetChar(Index);
if (c == '_')
{
++Index;
SkipWSOnly();
c = Code.GetChar(Index);
if (CharUtils.IsNewLine(c))
{
SkipNewline();
}
else
{
throw VBSyntaxError(VBSyntaxErrorCode.InvalidCharacter);
}
}
else
{
break;
}
}
}
private Token NextNumericLiteral()
{
int start = Index;
char c = Code.GetChar(Index);
char next = Code.GetChar(Index + 1);
string? dec = null;
StringBuilder?fstr = null;
if (c != '.')
{
if (c == '&')
{
if (CharUtils.Equals(next, 'h'))
{
return(NextHexIntLiteral());
}
else if (CharUtils.IsOctDigit(next))
{
return(NextOctIntLiteral());
}
else
{
throw VBSyntaxError(VBSyntaxErrorCode.SyntaxError);
}
}
else
{
dec = GetDecStr();
if (CharUtils.IsIdentifierStart(Code.GetChar(Index)))
{
throw VBSyntaxError(VBSyntaxErrorCode.ExpectedEndOfStatement);
}
}
}
c = Code.GetChar(Index);
if (c == '.')
{
++Index;
fstr ??= GetStringBuilder();
fstr.Append('.').Append(GetDecStr());
c = Code.GetChar(Index);
}
if (CharUtils.Equals(c, 'e'))
{
fstr ??= GetStringBuilder();
fstr.Append('e');
c = Code.GetChar(++Index);
if (c == '+' || c == '-')
{
++Index;
fstr.Append(c);
}
c = Code.GetChar(Index);
if (CharUtils.IsDecDigit(c))
{
fstr.Append(GetDecStr());
}
else
{
throw VBSyntaxError(VBSyntaxErrorCode.InvalidNumber);
}
}
c = Code.GetChar(Index);
if (CharUtils.IsIdentifierStart(c))
{
throw VBSyntaxError(VBSyntaxErrorCode.ExpectedEndOfStatement);
}
if (fstr != null && dec != null)
{
fstr.Insert(0, dec);
}
if (fstr != null)
{
return(new FloatLiteralToken
{
Start = start,
End = Index,
LineNumber = CurrentLine,
LineStart = CurrentLineStart,
Value = ParseDouble(fstr.ToString()),
});
}
var result = ParseInteger(dec !, 10);
result.Start = start;
return(result);
}
public Token NextToken()
{
SkipWhitespaces();
if (IsEof())
{
return(new EofToken
{
Start = Index,
End = Index,
LineNumber = CurrentLine,
LineStart = CurrentLineStart,
});
}
char c = Code.GetChar(Index);
char next = Code.GetChar(Index + 1);
if (CharUtils.IsLineTerminator(c))
{
return(NextLineTermination());
}
var comment = NextComment();
if (comment != null)
{
return(comment);
}
if (CharUtils.IsIdentifierStart(c))
{
return(NextIdentifier());
}
if (c == '"')
{
return(NextStringLiteral());
}
if (c == '.')
{
if (CharUtils.IsDecDigit(next))
{
return(NextNumericLiteral());
}
return(NextPunctuation());
}
if (CharUtils.IsDecDigit(c))
{
return(NextNumericLiteral());
}
if (c == '&')
{
if (CharUtils.Equals(next, 'h') || CharUtils.IsDecDigit(next))
{
return(NextNumericLiteral());
}
return(NextPunctuation());
}
if (c == '#')
{
return(NextDateLiteral());
}
if (c == '[')
{
return(NextExtendedIdentifier());
}
return(NextPunctuation());
}
