说明
- 本程序仅基于最小语法测试集，源代码本身不具有泛化能力
- 使用
python作为编程语言，应用了少量面向对象思想
- 自觉
变量名称设计规范，源代码易读，再此不做多余解释，有问题请留言
TEST_STRING = ["eadeaa", "edeaeaadabacae", "edeaebd"]
class Rules(object):
def __init__(self):
self.state = "E"
def error(self, position, content):
print("Position %d ,Error !!" % position, content[position])
exit(-1)
def log(self):
print("Stack: %s" % self.state)
def reduce(self, present_state, char, point):
temp = self.state[:-1]
if present_state == 'a' and char == 'a':
self.state = temp
elif present_state == 'b' and char == 'b':
self.state = temp
elif present_state == 'c' and char == 'c':
self.state = temp
elif present_state == 'd' and char == 'd':
self.state = temp
elif present_state == 'e' and char == 'e':
self.state = temp
else:
self.error(point, content)
def analyze(self, content, point):
char = content[point]
present_state = self.state[-1]
temp_state = self.state[0:-1]
if present_state == 'E' and char == 'e':
self.state = temp_state
self.state += "AaBe"
elif present_state == 'A':
if char == 'a':
self.state = temp_state
self.state += 'a'
elif char == 'b':
self.state = temp_state
self.state += 'BcAb'
elif present_state == 'B':
if char == 'd':
self.state = temp_state
self.state += 'dEd'
elif char == 'a':
self.state = temp_state
self.state += 'Ca'
elif present_state == 'C':
if char == 'e':
self.state = temp_state
self.state += 'e'
elif char == 'd':
self.state = temp_state
self.state += 'Cd'
self.reduce(self.state[-1], char, point)
point += 1
return point
class Tools(object):
@staticmethod
def process(content):
anaylzer = Rules()
point = 0
while point < len(content):
point = anaylzer.analyze(content, point)
anaylzer.log()
if __name__ == "__main__":
for content in TEST_STRING:
print("Test String: %s" % content)
Tools.process(content)
print('\n')
