/// <summary>
/// Scans through the window and generates a WhiteSpace SyntaxNode/Trivia
/// </summary>
/// <param name="TextWindow"></param>
/// <returns></returns>
public static SyntaxTrivia Scan(SlidingTextWindow TextWindow)
{
// Default to OnlyWhiteSpace true
Boolean bIsOnlySpaces = true;
Boolean bEndOfTrivia = false;
String sCharactersScannedSoFar = String.Empty;
while (!bEndOfTrivia && TextWindow.HasCharactersLeftToProcess())
{
// Peek at a character
char ch = TextWindow.PeekCharacter();
switch (ch)
{
case '\t': // Horizontal tab
case '\v': // Vertical Tab
case '\f': // Form-feed
case '\u001A':
bIsOnlySpaces = false;
goto case ' ';
case ' ':
sCharactersScannedSoFar += TextWindow.PopCharacter();
break;
case '\r': // Carriage Return
case '\n': // Line-feed
// End iteration
bEndOfTrivia = true;
break;
default:
if (ch > 127 && SyntaxUtilities.IsWhiteSpace(ch))
{
goto case '\t';
}
bEndOfTrivia = true;
break;
}
}
// Return the specific instance where possible
if (sCharactersScannedSoFar.Length == 0)
{
return(null);
}
if (bIsOnlySpaces && sCharactersScannedSoFar.Length == 1)
{
return(SyntaxFactory.Space);
}
else
{
return(SyntaxFactory.WhiteSpace(sCharactersScannedSoFar));
}
}
/// <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);
}