private BlockState TryParseListItem(BlockProcessor state, Block block)
{
var currentListItem = block as ListItemBlock;
var currentParent = block as ListBlock ?? (ListBlock)currentListItem?.Parent;
// We can early exit if we have a code indent and we are either (1) not in a ListItem, (2) preceded by a blank line, (3) in an unordered list
if (state.IsCodeIndent && (currentListItem is null || currentListItem.LastChild is BlankLineBlock || !currentParent.IsOrdered))
{
return(BlockState.None);
}
var initColumnBeforeIndent = state.ColumnBeforeIndent;
var initColumn = state.Column;
var sourcePosition = state.Start;
var sourceEndPosition = state.Line.End;
var c = state.CurrentChar;
var itemParser = mapItemParsers[c];
bool isOrdered = itemParser is OrderedListItemParser;
if (itemParser == null)
{
return(BlockState.None);
}
// Try to parse the list item
ListInfo listInfo;
if (!itemParser.TryParse(state, currentParent?.BulletType ?? '\0', out listInfo))
{
// Reset to an a start position
state.GoToColumn(initColumn);
return(BlockState.None);
}
// Gets the current character after a successful parsing of the list information
c = state.CurrentChar;
// Item starting with a blank line
int columnWidth;
// Do we have a blank line right after the bullet?
if (c == '\0')
{
// Use a negative number to store the number of expected chars
columnWidth = -(state.Column - initColumnBeforeIndent + 1);
}
else
{
if (!c.IsSpaceOrTab())
{
state.GoToColumn(initColumn);
return(BlockState.None);
}
// Parse the following indent
state.RestartIndent();
var columnBeforeIndent = state.Column;
state.ParseIndent();
// We expect at most 4 columns after
// If we have more, we reset the position
if (state.Indent > 4)
{
state.GoToColumn(columnBeforeIndent + 1);
}
// Number of spaces required for the following content to be part of this list item
// If the list item starts with a blank line, the number of spaces
// following the list marker doesn't change the required indentation
columnWidth = (state.IsBlankLine ? columnBeforeIndent : state.Column) - initColumnBeforeIndent;
}
// Starts/continue the list unless:
// - an empty list item follows a paragraph
// - an ordered list is not starting by '1'
var isPreviousParagraph = (block ?? state.LastBlock) is ParagraphBlock;
if (isPreviousParagraph)
{
var isOpen = state.IsOpen(block ?? state.LastBlock);
if (state.IsBlankLine || (isOpen && listInfo.BulletType == '1' && listInfo.OrderedStart != "1"))
{
state.GoToColumn(initColumn);
return(BlockState.None);
}
}
int.TryParse(listInfo.OrderedStart, out int order);
var newListItem = new ListItemBlock(this)
{
Column = initColumn,
ColumnWidth = columnWidth,
Order = order,
Span = new SourceSpan(sourcePosition, sourceEndPosition)
};
state.NewBlocks.Push(newListItem);
if (currentParent != null)
{
// If we have a new list item, close the previous one
if (currentListItem != null)
{
state.Close(currentListItem);
}
// Reset the list if it is a new list or a new type of bullet
if (currentParent.IsOrdered != isOrdered ||
currentParent.OrderedDelimiter != listInfo.OrderedDelimiter ||
currentParent.BulletType != listInfo.BulletType)
{
state.Close(currentParent);
currentParent = null;
}
}
if (currentParent == null)
{
var newList = new ListBlock(this)
{
Column = initColumn,
Span = new SourceSpan(sourcePosition, sourceEndPosition),
IsOrdered = isOrdered,
BulletType = listInfo.BulletType,
OrderedDelimiter = listInfo.OrderedDelimiter,
DefaultOrderedStart = listInfo.DefaultOrderedStart,
OrderedStart = listInfo.OrderedStart,
};
state.NewBlocks.Push(newList);
}
return(BlockState.Continue);
}
