internal override SourceLocation GetLocation(int position)
{
if (position < 0 || position > _document.Length)
{
throw new IndexOutOfRangeException(nameof(position));
}
var index = Array.BinarySearch <int>(_lineStarts, position);
if (index >= 0)
{
// We have an exact match for the start of a line.
Debug.Assert(_lineStarts[index] == position);
return(new SourceLocation(_document.GetFilePathForDisplay(), position, index, characterIndex: 0));
}
// Index is the complement of the line *after* the one we want, because BinarySearch tells
// us where we'd put position *if* it were the start of a line.
index = (~index) - 1;
if (index == -1)
{
// There's no preceding line, so it's based on the start of the string
return(new SourceLocation(_document.GetFilePathForDisplay(), position, 0, position));
}
else
{
var characterIndex = position - _lineStarts[index];
return(new SourceLocation(_document.GetFilePathForDisplay(), position, index, characterIndex));
}
}