public static SyntaxTrivia Scan(SlidingTextWindow TextWindow)
{
char xcNextChar = TextWindow.PeekCharacter();
switch (xcNextChar)
{
case '\r':
if (TextWindow.PeekCharacter(1) == '\n')
{
TextWindow.SkipAhead(2);
return(SyntaxFactory.EndOfLine("\r\n"));
}
return(SyntaxFactory.EndOfLine("\r"));
case '\n':
TextWindow.SkipAhead(1);
return(SyntaxFactory.EndOfLine("\n"));
default:
// Try again
if (SyntaxUtilities.IsNewLineCharacter(xcNextChar))
{
TextWindow.SkipAhead(1);
return(SyntaxFactory.EndOfLine("\n"));
}
return(null);
}
}
/// <summary>
/// Used to analyse the current textwindow and retrieve/skip any
/// trivia which includes things such as whitespace, newlines,
/// comments and multi-line comments
/// Returns them as a flat list
/// </summary>
/// <param name="bIsTrailing"></param>
/// <returns></returns>
private List <SyntaxTrivia> LexSyntaxTrivia(Boolean bIsTrailing = false)
{
// Initialise variables
List <SyntaxTrivia> aoReturnList = new List <SyntaxTrivia>();
Boolean bNewLineCharFound = false;
// Just keep lexing until we are told to stop
// or we run out of characters to process
while (TextWindow.HasCharactersLeftToProcess())
{
// Check the next character and switch based on that
char xcNextChar = TextWindow.PeekCharacter();
if (SyntaxUtilities.IsWhiteSpace(xcNextChar))
{
// Try and scan the item
SyntaxTrivia oNewItem = WhiteSpaceScanner.Scan(TextWindow);
// Insert it
aoReturnList.Add(oNewItem);
}
else if (SyntaxUtilities.IsNewLineCharacter(xcNextChar))
{
bNewLineCharFound = true;
// Do not steal trailing comments if a newline has been found
if (bIsTrailing)
{
break;
}
// Try and scan the item
SyntaxTrivia oNewItem = NewLineScanner.Scan(TextWindow);
// Insert it
aoReturnList.Add(oNewItem);
}
// Handle Comments
else if (xcNextChar == '-')
{
// Do not touch a single -, only play with --
if (TextWindow.PeekCharacter(1) != '-')
{
return(aoReturnList);
}
// Only pick up inlines if they are directly trailing an item
// Do not steal another nodes leading comments
if (bNewLineCharFound && bIsTrailing)
{
break;
}
SyntaxTrivia oComment = CommentScanner.ScanSingleLineComment(TextWindow);
aoReturnList.Add(oComment);
}
else if (xcNextChar == '/')
{
// Do not touch a single /, only play with /*
if (TextWindow.PeekCharacter(1) != '*')
{
return(aoReturnList);
}
// Do not steal trailing comments if a newline has been found
if (bNewLineCharFound && bIsTrailing)
{
break;
}
SyntaxTrivia oComment = CommentScanner.ScanMultiLineComment(TextWindow);
aoReturnList.Add(oComment);
}
else
{
break;
}
}
return(aoReturnList);
}
public static SyntaxTrivia ScanSingleLineComment(SlidingTextWindow TextWindow)
{
// Check next char
char xcNextChar = TextWindow.PeekCharacter();
// If it is two hypens together
if (xcNextChar == '-' && TextWindow.PeekCharacter(1) == '-')
{
// Ignore Comment syntax (we just want text)
TextWindow.SkipAhead(2);
Boolean bIsCommentTerminated = false;
String sCommentLine = String.Empty;
// Iterate indefinitely until we reach the end
for (int iIndex = 0; TextWindow.Position + iIndex < TextWindow.Count; iIndex++)
{
// NewLine char (Terminated properly)
if (SyntaxUtilities.IsNewLineCharacter(TextWindow.PeekCharacter(iIndex)))
{
// Break the loop and the comment is terminated properly
bIsCommentTerminated = true;
break;
}
// Keep adding characters to our intermediate var
sCommentLine += TextWindow.PeekCharacter(iIndex);
}
// Just advance the length of the text (we can't fix peoples comments 100%
// of the time)
TextWindow.SkipAhead(sCommentLine.Length);
// If our comment was terminated properly
if (bIsCommentTerminated)
{
return(SyntaxFactory.SingleLineComment(sCommentLine));
}
// Not terminated properly.. (hardest case)
// If we reach the end of the window its either an EOF comment (which is unlikely)
// or it is an unterminated comment
else
{
// Intermediate Var (Add all the text as a comment)
SyntaxTrivia oCommentNode = SyntaxFactory.SingleLineComment(sCommentLine);
// Add the erroraneous message
oCommentNode.Comments.Add(ErrorMessageLibrary.GetErrorMessage(8002, "Single Line Comment"));
// return the comment node with everything in comments
return(oCommentNode);
}
}
// This token should not be here (there is something wrong)
// Intermediate Var (Add all the text as a comment)
SyntaxTrivia oErraneousToken = new SyntaxTrivia(
SyntaxKind.UnknownNode, // Unknown
Convert.ToString(TextWindow.PeekCharacter())); // Get the character out of the stream
oErraneousToken.Comments.Add(ErrorMessageLibrary.GetErrorMessage(8001, Convert.ToString(TextWindow.PopCharacter())));
// return the comment node with everything in comments
return(oErraneousToken);
}