def closure_lr1(items, firsts):
closure = ContainerSet(*items)
changed = True
while changed:
new_items = ContainerSet()
for item in closure:
new_items.extend(expand(item, firsts))
changed = closure.update(new_items)
return compress(closure)
def ClosureLR1(items, firsts):
closure = ContainerSet(*items)
changed = True
while changed:
changed = False
new_items = ContainerSet()
for item in closure:
new_items.extend(LR1Parser.Expand(item, firsts))
changed = closure.update(new_items)
return LR1Parser.Compress(closure)
def closure_lr1(items, firsts):
closure = ContainerSet(*items)
changed = True
while changed:
changed = False
new_items = ContainerSet()
# Your code here!!!
for x in closure:
new_items.extend(expand(x, firsts))
changed = closure.update(new_items)
return compress(closure)
def closure_lr1(items, firsts, with_lookaheads=True):
closure = ContainerSet(*items)
changed = True
while changed:
changed = False
new_items = ContainerSet()
# Your code here!!!
for item in closure:
new_items.extend(expand(item, firsts))
changed = closure.update(new_items)
if with_lookaheads:
return compress(closure)
else:
return closure
def closure_lr0(items):
closure = ContainerSet(*items)
pending = list(items)
while pending:
current = pending.pop()
symbol = current.NextSymbol
if current.IsReduceItem or symbol.IsTerminal:
continue
new_items = [
Item(p, 0) for p in symbol.productions if Item(p, 0) not in closure
]
pending += new_items
closure.extend(new_items)
return frozenset(closure)