/// <summary>
/// Illustration : lines with code elements continued from previous line or with a continuation on next line (before update)
/// SW represents a code element starting word
/// [ SW x]
/// [ x]
/// [SW x]
/// [ SW ]
/// [ x SW]
/// A DocumentChange intersects with a previously parsed multiline code element if :
/// * LineInserted :
/// - all previous lines until the last starting word
/// (get previous lines until the previous code element is found)
/// - all the next lines until the next starting word
/// (get next lines until the next code element is found,
/// do not reset the last line if the next code element starts at the beginning of the line)
/// * LineUpdated / LineRemoved :
/// - all previous lines until the last starting word
/// (get previous lines until the previous code element is found)
/// - all the next lines until the next starting word
/// (get next lines until the next code element is found,
/// do not reset the last line if the next code element starts at the beginning of the line)
/// When navigating to previous or next line searching for a code element, we can stop when a fresh insertion / update is encountered.
/// When we reset a line which was not directly updated, and where the code element started in the middle of the line,
/// we must "remember" at which token we must start parsing.
/// In conclusion, the incremental parsing step for code elements is divided in two steps :
/// 1. List all the starting and stop tokens of sections to parse with the rules above
/// 2. Parse code elements beginning with starting token and until we reach stop token
/// </summary>
private static ParseSection CheckIfAdjacentLinesNeedRefresh(DocumentChangeType changeType, int lineIndex, ISearchableReadOnlyList <CodeElementsLine> documentLines, PrepareDocumentLineForUpdate prepareDocumentLineForUpdate, IList <DocumentChange <ICodeElementsLine> > codeElementsLinesChanges, ParseSection lastParseSection)
{
ParseSection currentParseSection = new ParseSection();
// Navigate backwards to the start of the multiline code element
if (lineIndex > 0)
{
int previousLineIndex = lineIndex;
int lastLineIndexReset = lastParseSection != null ? lastParseSection.StopLineIndex : -1;
IEnumerator <CodeElementsLine> reversedEnumerator = documentLines.GetEnumerator(previousLineIndex - 1, -1, true);
bool previousLineHasCodeElements = false;
while (reversedEnumerator.MoveNext() && (--previousLineIndex > lastLineIndexReset))
{
// Get the previous line until the first code element is encountered
CodeElementsLine previousLine = reversedEnumerator.Current;
// The start of the parse section is delimited by the previous CodeElement
if (previousLine != null)
{
previousLineHasCodeElements = previousLine.HasCodeElements;
if (previousLineHasCodeElements)
{
currentParseSection.StartLineIndex = previousLineIndex;
currentParseSection.StartToken = previousLine.CodeElements.First().ConsumedTokens.FirstOrDefault();
}
// All lines contained in the parse section could be modified, and should be reset
previousLine = (CodeElementsLine)prepareDocumentLineForUpdate(previousLineIndex, previousLine, CompilationStep.CodeElementsParser);
previousLine.ResetCodeElements();
codeElementsLinesChanges.Add(new DocumentChange <ICodeElementsLine>(DocumentChangeType.LineUpdated, previousLineIndex, previousLine));
}
// Stop iterating backwards as soon as the start of an old CodeElement is found
if (previousLineHasCodeElements)
{
break;
}
}
// If no CodeElement was found on the previous lines, current parse section starts at the beggining of the file
// (because last parseSection could only stop at a CodeElement or at the end of the file)
if (!previousLineHasCodeElements)
{
currentParseSection.StartLineIndex = 0;
currentParseSection.StartToken = null;
}
}
// If line 0 was updated, current parse section starts at the beggining of the file
else
{
currentParseSection.StartLineIndex = 0;
currentParseSection.StartToken = null;
}
// Navigate forwards to the end of the multiline code element
if (lineIndex < (documentLines.Count - 1))
{
int nextLineIndex = lineIndex;
IEnumerator <CodeElementsLine> enumerator = documentLines.GetEnumerator(nextLineIndex + 1, -1, false);
bool nextLineHasCodeElements = false;
while (enumerator.MoveNext())
{
// Get the next line until non continuation line is encountered
nextLineIndex++;
CodeElementsLine nextLine = enumerator.Current;
// Check if the next CodeElement found starts at the beginning of the line
if (nextLine != null)
{
nextLineHasCodeElements = nextLine.HasCodeElements;
bool nextCodeElementStartsAtTheBeginningOfTheLine = false;
if (nextLineHasCodeElements)
{
try
{
Token startTokenForNextParseSection = nextLine.CodeElements.First().ConsumedTokens.FirstOrDefault();
Token firstSourceTokenOfThisLine = nextLine.TokensWithCompilerDirectives.First(token => token.Channel == Token.CHANNEL_SourceTokens);
nextCodeElementStartsAtTheBeginningOfTheLine = startTokenForNextParseSection == firstSourceTokenOfThisLine;
}
catch (System.InvalidOperationException /*e*/)
{//JCM: 28/08/2017: I noticed that this Exception can occur if: it doesn't exists a token which verifies the predicate: token.Channel == Token.CHANNEL_SourceToken
nextCodeElementStartsAtTheBeginningOfTheLine = false;
}
}
// All lines contained in the parse section could be modified
if (!nextCodeElementStartsAtTheBeginningOfTheLine)
{
// TO DO : ERROR below, will not work if we have source tokens from previous CodeElement + one other CodeElement on the same line
// => the other CodeElement will be deleted by prepareDocumentLineForUpdate and not parsed again
nextLine = (CodeElementsLine)prepareDocumentLineForUpdate(nextLineIndex, nextLine, CompilationStep.CodeElementsParser);
codeElementsLinesChanges.Add(new DocumentChange <ICodeElementsLine>(DocumentChangeType.LineUpdated, nextLineIndex, nextLine));
}
// Stop iterating forwards as soon as the start of an old CodeElement is found
if (nextLineHasCodeElements)
{
currentParseSection.StopLineIndex = nextLineIndex;
currentParseSection.StopToken = nextLine.CodeElements.First().ConsumedTokens.FirstOrDefault();
currentParseSection.StopTokenIsFirstTokenOfTheLine = nextCodeElementStartsAtTheBeginningOfTheLine;
break;
}
}
}
// If no CodeElement was found on the next lines, current parse section current parse section ends at the end of the file
if (!nextLineHasCodeElements)
{
currentParseSection.StopLineIndex = nextLineIndex;
currentParseSection.StopToken = null;
currentParseSection.StopTokenIsFirstTokenOfTheLine = false;
}
}
// If last line was updated, or if no CodeElement was found after the updated line, current parse section ends at the end of the file
else
{
currentParseSection.StopLineIndex = documentLines.Count - 1;
currentParseSection.StopToken = null;
currentParseSection.StopTokenIsFirstTokenOfTheLine = false;
}
return(currentParseSection);
}
