def _build_parsing_table(self):
G = self.G.AugmentedGrammar(True)
automaton = build_LR1_automaton(G)
centers = {}
for i, node in enumerate(automaton):
node.idx = i
try:
same_center = centers[node_centers(node)]
centers[node_centers(node)] = State(
compress(node.state.union(same_center.state)), True)
except KeyError:
centers[node_centers(node)] = node
centers[node_centers(node)].idx = i
self.automaton = automaton
self.centers = centers
Goto = {}
firsts = compute_firsts(G)
firsts[G.EOF] = ContainerSet(G.EOF)
for node in centers.values():
for symbol in G.terminals + G.nonTerminals:
temp = goto_lr1(node.state, symbol, firsts)
if not temp:
continue
Goto[(node.idx,
symbol)] = centers[node_centers(State(temp, True))]
for node in centers.values():
idx = node.idx
for item in node.state:
# Your code here!!!
# - Fill `self.Action` and `self.Goto` according to `item`)
# - Feel free to use `self._register(...)`)
if item.IsReduceItem:
production = item.production
if production.Left == G.startSymbol:
self._register(self.action, (idx, G.EOF), ("OK", None))
else:
for lookahead in item.lookaheads:
self._register(self.action, (idx, lookahead),
("REDUCE", production))
else:
next_symbol = item.NextSymbol
if next_symbol.IsTerminal:
self._register(
self.action, (idx, next_symbol),
("SHIFT", Goto[(node.idx, next_symbol)].idx))
else:
self._register(self.goto, (idx, next_symbol),
Goto[(node.idx, next_symbol)].idx)
def state_transpose(initial_state: State):
"""
returns the state equivalent to initial_state on the transpose graph and a dictionary mapping idx to new states transposed
"""
state_dict = {
} # state_dict[key] = (original_state,copy_of_original_state_with_transposed_transitions)
idx = 0
for x in initial_state:
new_state = State(x.state, x.final, x.formatter, x.shape)
if not hasattr(x, 'idx'):
x.idx = idx
idx += 1
new_state.idx = x.idx
state_dict[x.idx] = (x, new_state)
for x in initial_state:
for key, states in x.transitions.items():
for state in states:
state_dict[state.idx][1].add_transition(
key, state_dict[x.idx][1])
return state_dict[initial_state.idx][1], state_dict
