/// <summary>
/// Extracts the code fragments based on the current file content that need to be re-processed due to content changes on the given lines.
/// Ignores any whitespace or comments at the beginning of the file (whether they have changed or not).
/// Ignores any whitespace or comments that occur after the last piece of code in the file.
/// Throws an ArgumentNullException if any of the arguments is null.
/// </summary>
private static IEnumerable <CodeFragment> FragmentsToProcess(this FileContentManager file, SortedSet <int> changedLines)
{
// NOTE: I suggest not to touch this routine unless absolutely necessary...(things *will* break)
if (file == null)
{
throw new ArgumentNullException(nameof(file));
}
if (changedLines == null)
{
throw new ArgumentNullException(nameof(changedLines));
}
var iter = changedLines.GetEnumerator();
var lastInFile = LastInFile(file);
Position processed = new Position(0, 0);
while (iter.MoveNext())
{
QsCompilerError.Verify(0 <= iter.Current && iter.Current < file.NrLines(), "index out of range for changed line");
if (processed.Line < iter.Current)
{
var statementStart = file.PositionAfterPrevious(new Position(iter.Current, 0));
if (processed.IsSmallerThan(statementStart))
{
processed = statementStart;
}
}
while (processed.Line <= iter.Current && processed.IsSmallerThan(lastInFile))
{
processed = processed.Copy(); // because we don't want to modify the ending of the previous code fragment ...
var nextEnding = file.FragmentEnd(ref processed);
var extractedPiece = file.GetCodeSnippet(new Range {
Start = processed, End = nextEnding
});
// constructing the CodeFragment -
// NOTE: its Range.End is the position of the delimiting char (if such a char exists), i.e. the position right after Code ends
if (extractedPiece.Length > 0) // length = 0 can occur e.g. if the last piece of code in the file does not terminate with a statement ending
{
var code = file.GetLine(nextEnding.Line).ExcessBracketPositions.Contains(nextEnding.Character - 1)
? extractedPiece.Substring(0, extractedPiece.Length - 1)
: extractedPiece;
if (code.Length == 0 || !CodeFragment.DelimitingChars.Contains(code.Last()))
{
code = $"{code}{CodeFragment.MissingDelimiter}";
}
var endChar = nextEnding.Character - (extractedPiece.Length - code.Length) - 1;
var codeRange = new Range {
Start = processed, End = new Position(nextEnding.Line, endChar)
};
yield return(new CodeFragment(file.IndentationAt(codeRange.Start), codeRange, code.Substring(0, code.Length - 1), code.Last()));
}
processed = nextEnding;
}
}
}