def populate_action_table_from_state(grammar, state_set, action_table,
handle_shift_reduce, to_id):
'''Builds the Action table.'''
for item in state_set:
next_symbol = item.next_symbol(grammar)
if item.sym_production == grammar.START and item.position == 1:
#Item is S' -> S*
action = Driver.Accept()
if grammar.EOF in action_table[to_id[state_set]] and \
action != action_table[to_id[state_set]][grammar.EndOfSource]:
raise KeyError(grammar.EOF)
action_table[to_id[state_set]][grammar.EOF] = action
elif next_symbol and not grammar.is_a_nonterminal(next_symbol):
#Item is A -> a*bc
assert not grammar.is_empty(next_symbol)
goto_state_hash = to_id[goto(state_set, next_symbol, grammar)]
action = Driver.Shift(
goto_state_hash, item.sym_production,
grammar[item.sym_production][item.alternative])
if next_symbol in action_table[to_id[state_set]] and \
action != action_table[to_id[state_set]][next_symbol]:
action = handler_conflict(
action, action_table[to_id[state_set]][next_symbol],
next_symbol, handle_shift_reduce)
action_table[to_id[state_set]][next_symbol] = action
elif not next_symbol: #Item is A -> abc*
for terminal in item.followers(grammar):
semantic_definition = grammar.semantic_definition(
item.sym_production, item.alternative)
action = Driver.Reduce(
item.sym_production,
grammar[item.sym_production][item.alternative],
semantic_definition,
grammar.is_empty_rule(
(grammar[item.sym_production][item.alternative])))
if terminal in action_table[to_id[state_set]] and \
action != action_table[to_id[state_set]][terminal]:
action = handler_conflict(
action, action_table[to_id[state_set]][terminal],
terminal, handle_shift_reduce)
action_table[to_id[state_set]][terminal] = action
