def _build_vflist(elements):
# Iterate through the list of elements, keeping track of state, and
# for each vf element create a VariantForm object based on current
# state (the set of dates and grammar information governing the vf).
# 'state' is used to keep track of state:
# state['outside'] keeps track of the main state, i.e. state outside
# parens. Includes:
# -- last encountered date-range;
# -- last encountered grammar information (<gr>);
# -- last encountered label (<la>).
# state['inside'] keeps track of the state inside parens.
# Includes:
# -- last encountered date-range;
# -- last encountered grammar information (<gr>);
# -- last encountered label (<la>).
# This is cleared every time we hit a closing paren.
# state['parens'] keeps track of whether we're inside or outside
# parens (value is 'inside' or 'outside').
# Each time a <vf> is encountered, a VariantForm is created
# for it using information from the current state. Usually this is
# state['outside']. Values from state['inside'] are only used if the
# <vf> is inside parens (i.e. state['parens'] == 'inside') *and* the
# value of state['inside'] is populated; otherwise, the corresponding
# value from state['outside'] is used by default.
# All __state is cleared every time we reach a hard break (e.g. a para).
vf_list = []
state = StateMachine()
for element in elements:
element = _adjust_element(element, state)
if element.tag == 'vf':
date_start, date_end = state.read('date_range')
if not date_start:
date_start, date_end = state.read('date_range',
paren_state='outside')
grammar = (state.read('grammar') or
state.read('grammar', paren_state='outside'))
label = (state.read('label') or
state.read('label', paren_state='outside'))
variant_form = VariantFormFromParser(element.node,
date_start,
date_end)
variant_form.set_grammatical_information(grammar)
variant_form.label = label
vf_list.append(variant_form)
elif element.tag == 'vd':
state.set('date_range', utilities.find_range(element.text))
if element.previous != 'la':
state.set('label', '')
elif element.tag == 'hardBreak' or element.tag == 'p':
state.clear()
elif element.tag == 'softBreak':
state.set('parens', 'outside')
state.set('label', '')
elif element.tag == 'openParen' and element.next != 'vf':
state.set('parens', 'inside')
# Make sure that grammar and date-range inside parens are set to null
state.set('grammar', '')
state.set('label', '')
state.set('date_range', (0, 0))
elif element.tag == 'closeParen':
state.set('parens', 'outside')
elif ((element.tag == 'gr' or element.tag == 'text') and
element.text and
not IGNORABLE_GRAMMAR_PATTERN.search(element.text)):
state.set('grammar', element.text)
elif element.tag == 'la':
state.set('label', element.text)
elif element.tag == 'newStart':
vf_list = []
state.clear()
return vf_list
