def nestSections(block, level=1):
"""
Sections aren't handled by CommonMark at the moment.
This function adds sections to a block of nodes.
'title' nodes with an assigned level below 'level' will be put in a child section.
If there are no child nodes with titles of level 'level' then nothing is done
"""
cur = block.first_child
if cur is not None:
children = []
# Do we need to do anything?
nest = False
while cur is not None:
if cur.t == 'heading' and cur.level == level:
nest = True
break
cur = cur.nxt
if not nest:
return
section = Node('MDsection', 0)
section.parent = block
cur = block.first_child
while cur is not None:
if cur.t == 'heading' and cur.level == level:
# Found a split point, flush the last section if needed
if section.first_child is not None:
finalizeSection(section)
children.append(section)
section = Node('MDsection', 0)
nxt = cur.nxt
# Avoid adding sections without titles at the start
if section.first_child is None:
if cur.t == 'heading' and cur.level == level:
section.append_child(cur)
else:
children.append(cur)
else:
section.append_child(cur)
cur = nxt
# If there's only 1 child then don't bother
if section.first_child is not None:
finalizeSection(section)
children.append(section)
block.first_child = None
block.last_child = None
nextLevel = level + 1
for child in children:
# Handle nesting
if child.t == 'MDsection':
nestSections(child, level=nextLevel)
# Append
if block.first_child is None:
block.first_child = child
else:
block.last_child.nxt = child
child.parent = block
child.nxt = None
child.prev = block.last_child
block.last_child = child
