def __call__(self, namespace, env, source, benchmark=False):
if benchmark:
now = time.time()
print 'start parsing'
parser = earley.Parser(self.init, self.nullable)
stream = L2(CStream(source), self.symboltab)
indent_stack = []
indent = 0 if stream.first is None else stream.first.start.col
line = 0 if stream.first is None else stream.first.start.lno
while stream.filled:
if line < stream.first.start.lno:
while stream.first.start.col < indent and 'dedent' in parser.expect:
start = stream.first.start
parser.step(Literal(start, start, 'dedent', ''))
indent = indent_stack.pop()
if stream.first.start.col < indent:
raise Exception("Uneven indent at line %s" %
stream.first.start)
if stream.first.start.col == indent and 'newline' in parser.expect:
start = stream.first.start
parser.step(Literal(start, start, 'newline', ''))
if stream.first.start.col > indent and 'indent' in parser.expect:
start = stream.first.start
parser.step(Literal(start, start, 'indent', ''))
indent_stack.append(indent)
indent = stream.first.start.col
line = stream.first.start.lno
expect = parser.expect
token = stream.advance()
parser.step(token)
if len(parser.chart[-1]) == 0:
if self.debug: print_result(parser)
trail = format_expect(expect)
raise Exception(
"{0.lno}:{0.col}: parse error at {1.name} {1.value!r}\n{2}"
.format(token.start, token, trail))
while 'dedent' in parser.expect:
stop = token.stop
parser.step(Literal(stop, stop, 'dedent', ''))
if not parser.accept:
if self.debug: print_result(parser)
trail = format_expect(parser.expect)
raise Exception(
"{0.lno}:{0.col}: parse error at end of file\n{1}".format(
stream.stream, trail))
if self.debug: print_result(parser)
if benchmark:
trav = time.time()
print 'parsing took:', trav - now
results = traverse(parser, parser.root, 0, len(parser.input),
namespace, env)
if benchmark:
print 'traverse took:', time.time() - trav
return results
return token.value == 'earley' and token.lsp == token.rsp == False
grammar = [
#Rule('file', []), # XXX: fix a bug, if you use empty rule instead, it won't parse
# XXX: verify that the bug fix works.
Rule('file', ['term']),
Rule('file', ['term', 'file']),
Rule('term', ['symbol']),
#Rule('term', ['leftparen', early, 'rightparen']),
]
init, nullable = earley.simulate(grammar, 'file', True)
source = open(sys.argv[1]).read()
stream = L2(CStream(source), table)
parser = earley.Parser(init, nullable)
while stream.filled:
token = stream.advance()
parser.step(token)
earley.print_result(parser)
def traverse(parser, rule, start, stop):
midresults = list(parser.chains(rule.rhs, start, stop))
for midresult in midresults:
print start, stop, rule.lhs, midresult
if len(midresults) > 1:
raise Exception("ambiguity at {}:{}".format(start, stop))
for midresult in midresults: