def __match__identifier__(self, c): # 匹配标识符（也有可能是关键字）
ans = c
c = self.pre_read()
while c != -1 and (c == '_' or Utils.is_digit(c) or Utils.is_alpha(c)):
ans += c
c = self.pre_read(ans)
if c == -1:
return c
if c in "$@~": # 不会出现在标识符后面的字符
self.tokens.append(
Utils.GetErrorElement(self.lineno, "invalid identifier"))
else:
ans = ans.lower()
self.tokens.append(
Utils.StringToKeyWordMap.get(ans)
or Utils.StringToIdentifierElement(ans))
return c
def __match_string__(self): # 匹配字符串
t = ""
success = True
while True:
c = self.read()
if c == -1 or c == '\n': # 错误，读入下一行
self.tokens.append(
Utils.GetErrorElement(self.lineno, "invalid string"))
self.readline()
success = False
break
if c != '"':
t += c
else:
break
if success:
self.tokens.append(Utils.StringToStringLiteral(t))
return self.pre_read()
def __match_number__(self, c): # 匹配数字
success = True
num = c
base = 10
c = self.pre_read(c)
if c == -1:
return c
if num == '0' and Utils.is_Hex(c):
num += c
base = 16
c = self.read()
elif num == '0' and Utils.is_digit(c):
base = 8
while c != -1:
if base == 16 and (Utils.is_digit(c) or 'a' < c < 'f'
or 'A' < c < 'F'):
num += c
elif base == 10 and (Utils.is_digit(c) or c == '.'):
num += c
elif base == 8 and (Utils.is_digit(c) and '0' < c < '9'):
num += c
else:
if Utils.is_alpha(c):
success = False
break
c = self.pre_read()
if not success:
self.tokens.append(
Utils.GetErrorElement(self.lineno, "invalid number"))
self.readline()
return self.pre_read()
if '.' in num and base == 10: # 小数
self.tokens.append(Utils.StringToFloatLiteral(num))
else: # 整数
self.tokens.append(Utils.StringToIntegerLiteral(num, base))
return c
def analyse(self): # 词法分析过程
c = self.read()
while c != -1:
while True: # 处理非法字符，空白和换行
if c == '\uFFFF': # INVALID CHARACTER
return
elif c == ' ' or c == '\t': # 空白，跳过
pass
elif c == '\n' or c == '\r': # 换行，读入下一行
self.readline()
else: # 其他的字符进入匹配
valid = True
break
c = self.read()
if c == -1:
return
if c == '-':
c = self.__match_non_word__(c, ['-', '='])
if c == -1:
return
valid = False
elif c == '+':
c = self.__match_non_word__(c, ['+', '='])
if c == -1:
return
valid = False
elif c == '*':
c = self.__match_non_word__(c, ['='])
if c == -1:
return
valid = False
elif c == '/':
c = self.__match_non_word__(c, ['=', '/'])
if c == -1:
return
valid = False
elif c == '|':
c = self.__match_non_word__(c, ['|'])
if c == -1:
return
valid = False
elif c == '&':
c = self.__match_non_word__(c, ['&'])
if c == -1:
return
valid = False
elif c == '<':
c = self.__match_non_word__(c, ['=', '>', '<'])
if c == -1:
return
valid = False
elif c == '>':
c = self.__match_non_word__(c, ['=', '>'])
if c == -1:
return
valid = False
elif c == ':':
c = self.__match_non_word__(c, ['='])
if c == -1:
return
valid = False
elif c == '!':
c = self.__match_non_word__(c, ['='])
if c == -1:
return
valid = False
elif c == '=':
c = self.__match_non_word__(c, ['='])
if c == -1:
return
valid = False
elif c in ';()[]{},^':
c = self.__match_non_word__(c, [])
if c == -1:
return
valid = False
elif c == '"':
c = self.__match_string__()
if c == -1:
return
valid = False
if valid:
if Utils.is_digit(c):
c = self.__match_number__(c)
if c == -1:
return
elif Utils.is_alpha(c) or c == '_':
c = self.__match__identifier__(c)
if c == -1:
return
else:
self.tokens.append(
Utils.GetErrorElement(self.lineno,
"invalid identifier"))
self.readline()
c = self.pre_read()
if c == -1:
return c