public SyntaxToken Lex()
{
TextWindow.Start();
char c = TextWindow.PeekChar();
if (TextUtilities.IsWhitespaceChar(c))
{
TextWindow.AdvanceChar();
return(SyntaxFactory.Whitespace(_snapshot, TextWindow.StringStart, TextWindow.Width));
}
if (TextUtilities.IsNewLine(c))
{
switch (c)
{
case '\r':
{
if (TextWindow.PeekChar(1) == '\n')
{
TextWindow.AdvanceChar(2);
return(SyntaxFactory.EndOfLine(_snapshot, TextWindow.StringStart, TextWindow.Width));
}
TextWindow.AdvanceChar();
return(SyntaxFactory.EndOfLine(_snapshot, TextWindow.StringStart, TextWindow.Width));
}
case '\n':
{
TextWindow.AdvanceChar();
return(SyntaxFactory.EndOfLine(_snapshot, TextWindow.StringStart, TextWindow.Width));
}
}
}
if (TextUtilities.IsIdentifierStartCharacter(c))
{
TextWindow.AdvanceChar();
while (TextUtilities.IsIdentifierPartCharacter(TextWindow.PeekChar()))
{
TextWindow.AdvanceChar();
}
return(SyntaxFactory.Identifier(_snapshot, TextWindow.StringStart, TextWindow.Width));
}
if (TextUtilities.IsQuoteChar(c))
{
if (TextWindow.PeekChar(1) == '\\' && TextWindow.PeekChar(2) == 'u')
{
TextWindow.AdvanceChar(8);
return(SyntaxFactory.CharacterLiteral(_snapshot, TextWindow.StringStart, TextWindow.Width));
}
return(ScanStringLiteral());
}
if (c == '?')
{
return(ScanSpecialSequence());
}
switch (c)
{
case ':':
{
if (TextWindow.PeekChar(1) == ':')
{
TextWindow.AdvanceChar();
if (TextWindow.PeekChar(1) == '=')
{
TextWindow.AdvanceChar();
return(SyntaxFactory.Defining(_snapshot, TextWindow.StringStart, TextWindow.Width));
}
else if (TextWindow.PeekChar(1) == '-')
{
TextWindow.AdvanceChar();
return(SyntaxFactory.Defining(_snapshot, TextWindow.StringStart, TextWindow.Width));
}
return(SyntaxFactory.Defining(_snapshot, TextWindow.StringStart, TextWindow.Width));
}
TextWindow.AdvanceChar();
return(SyntaxFactory.Defining(_snapshot, TextWindow.StringStart, TextWindow.Width));
}
case ';':
{
TextWindow.AdvanceChar();
return(SyntaxFactory.Terminator(_snapshot, TextWindow.StringStart, TextWindow.Width));
}
case '-':
{
TextWindow.AdvanceChar();
return(SyntaxFactory.Minus(_snapshot, TextWindow.StringStart, TextWindow.Width));
}
case '+':
{
TextWindow.AdvanceChar();
return(SyntaxFactory.Plus(_snapshot, TextWindow.StringStart, TextWindow.Width));
}
case '*':
{
TextWindow.AdvanceChar();
return(SyntaxFactory.Star(_snapshot, TextWindow.StringStart, TextWindow.Width));
}
case '/':
{
TextWindow.AdvanceChar();
return(SyntaxFactory.Slash(_snapshot, TextWindow.StringStart, TextWindow.Width));
}
case '.':
{
if (TextWindow.PeekChar(1) == '.')
{
TextWindow.AdvanceChar(2);
return(SyntaxFactory.CharacterRange(_snapshot, TextWindow.StringStart, TextWindow.Width));
}
TextWindow.AdvanceChar();
return(SyntaxFactory.Terminator(_snapshot, TextWindow.StringStart, TextWindow.Width));
}
case '|':
{
TextWindow.AdvanceChar();
return(SyntaxFactory.Separator(_snapshot, TextWindow.StringStart, TextWindow.Width));
}
case '(':
{
if (TextWindow.PeekChar(1) == '*')
{
return(ScanComment());
}
TextWindow.AdvanceChar();
return(SyntaxFactory.OpenParen(_snapshot, TextWindow.StringStart, TextWindow.Width));
}
case '[':
{
TextWindow.AdvanceChar();
return(SyntaxFactory.OpenBracket(_snapshot, TextWindow.StringStart, TextWindow.Width));
}
case '{':
{
TextWindow.AdvanceChar();
return(SyntaxFactory.OpenBrace(_snapshot, TextWindow.StringStart, TextWindow.Width));
}
case ')':
{
TextWindow.AdvanceChar();
return(SyntaxFactory.CloseParen(_snapshot, TextWindow.StringStart, TextWindow.Width));
}
case ']':
{
TextWindow.AdvanceChar();
return(SyntaxFactory.CloseBracket(_snapshot, TextWindow.StringStart, TextWindow.Width));
}
case '}':
{
TextWindow.AdvanceChar();
return(SyntaxFactory.CloseBrace(_snapshot, TextWindow.StringStart, TextWindow.Width));
}
default:
{
TextWindow.AdvanceChar();
break;
}
}
return(null);
}
public SyntaxToken LexSyntaxToken()
{
if (_lexerMode != LexerMode.None)
{
if (_lexerMode == LexerMode.SpecialSequenceContent)
{
_lexerMode = LexerMode.SpecialSequenceToken;
return(ScanSpecialSequence());
}
if (_lexerMode == LexerMode.SpecialSequenceToken)
{
TextWindow.Start();
TextWindow.AdvanceChar();
_lexerMode = LexerMode.None;
return(SyntaxFactory.SpecialSequence(_snapshot, TextWindow.StringStart, TextWindow.Width));
}
}
while (TextWindow.More())
{
TextWindow.Start();
char c = TextWindow.PeekChar();
if (TextUtilities.IsIdentifierStartCharacter(c))
{
TextWindow.AdvanceChar();
while (TextUtilities.IsIdentifierPartCharacter(TextWindow.PeekChar()))
{
TextWindow.AdvanceChar();
}
return(SyntaxFactory.Identifier(_snapshot, TextWindow.StringStart, TextWindow.Width));
}
switch (c)
{
case '\'':
case '"':
{
return(ScanStringLiteral());
}
case ' ':
case '\t': // Horizontal tab
case '\v': // Vertical Tab
case '\f': // Form-feed
case '\u001A':
{
while (TextUtilities.IsWhitespaceChar(c))
{
TextWindow.AdvanceChar();
c = TextWindow.NextChar();
}
return(SyntaxFactory.Whitespace(_snapshot, TextWindow.StringStart, TextWindow.Width));
}
case '\r':
case '\n':
{
if (c == '\r' && TextWindow.PeekChar(1) == '\n')
{
TextWindow.AdvanceChar(2);
return(SyntaxFactory.EndOfLine(_snapshot, TextWindow.StringStart, TextWindow.Width));
}
TextWindow.AdvanceChar();
return(SyntaxFactory.EndOfLine(_snapshot, TextWindow.StringStart, TextWindow.Width));
}
case '(':
{
if (TextWindow.PeekChar(1) == '*')
{
return(ScanComment());
}
TextWindow.AdvanceChar();
return(SyntaxFactory.OpenParen(_snapshot, TextWindow.StringStart, TextWindow.Width));
}
case '?':
{
_lexerMode = LexerMode.SpecialSequenceContent;
TextWindow.AdvanceChar();
return(SyntaxFactory.SpecialSequence(_snapshot, TextWindow.StringStart, TextWindow.Width));
}
case ':':
{
if (TextWindow.PeekChar(1) == ':')
{
TextWindow.AdvanceChar();
if (TextWindow.PeekChar(1) == '=')
{
TextWindow.AdvanceChar();
return(SyntaxFactory.Defining(_snapshot, TextWindow.StringStart, TextWindow.Width));
}
else if (TextWindow.PeekChar(1) == '-')
{
TextWindow.AdvanceChar();
return(SyntaxFactory.Defining(_snapshot, TextWindow.StringStart, TextWindow.Width));
}
return(SyntaxFactory.Defining(_snapshot, TextWindow.StringStart, TextWindow.Width));
}
TextWindow.AdvanceChar();
return(SyntaxFactory.Defining(_snapshot, TextWindow.StringStart, TextWindow.Width));
}
case ';':
{
TextWindow.AdvanceChar();
return(SyntaxFactory.Terminator(_snapshot, TextWindow.StringStart, TextWindow.Width));
}
case '-':
{
TextWindow.AdvanceChar();
return(SyntaxFactory.Minus(_snapshot, TextWindow.StringStart, TextWindow.Width));
}
case '+':
{
TextWindow.AdvanceChar();
return(SyntaxFactory.Plus(_snapshot, TextWindow.StringStart, TextWindow.Width));
}
case '*':
{
TextWindow.AdvanceChar();
return(SyntaxFactory.Star(_snapshot, TextWindow.StringStart, TextWindow.Width));
}
case '/':
{
TextWindow.AdvanceChar();
return(SyntaxFactory.Slash(_snapshot, TextWindow.StringStart, TextWindow.Width));
}
case '.':
{
if (TextWindow.PeekChar(1) == '.')
{
TextWindow.AdvanceChar(2);
return(SyntaxFactory.CharacterRange(_snapshot, TextWindow.StringStart, TextWindow.Width));
}
TextWindow.AdvanceChar();
return(SyntaxFactory.Terminator(_snapshot, TextWindow.StringStart, TextWindow.Width));
}
case '|':
{
TextWindow.AdvanceChar();
return(SyntaxFactory.Separator(_snapshot, TextWindow.StringStart, TextWindow.Width));
}
case '[':
{
TextWindow.AdvanceChar();
return(SyntaxFactory.OpenBracket(_snapshot, TextWindow.StringStart, TextWindow.Width));
}
case '{':
{
TextWindow.AdvanceChar();
return(SyntaxFactory.OpenBrace(_snapshot, TextWindow.StringStart, TextWindow.Width));
}
case ')':
{
TextWindow.AdvanceChar();
return(SyntaxFactory.CloseParen(_snapshot, TextWindow.StringStart, TextWindow.Width));
}
case ']':
{
TextWindow.AdvanceChar();
return(SyntaxFactory.CloseBracket(_snapshot, TextWindow.StringStart, TextWindow.Width));
}
case '}':
{
TextWindow.AdvanceChar();
return(SyntaxFactory.CloseBrace(_snapshot, TextWindow.StringStart, TextWindow.Width));
}
}
break;
}
return(null);
}
