#!/user/bin/env?python3
#?-*-?coding:?utf-8?-*-
‘‘‘
@Copyright：Zhixing?Tu

@Date：2020/6/4??6:34?下午

@File：Lab_2.py

@IDE：PyCharm
‘‘‘

‘‘‘
在實驗一的基礎上進行語法分析

E→TE‘
E‘→+TE‘|?-TE‘?|ε
T→FT‘
T‘→*FT‘|?/FT‘?|ε
F→（E）?|?id?|num

保留關鍵字及種別編碼
Static_word?=?{“begin“:?1?“end“:?2?“if“:?3?“then“:?4?“while“:?5
???????????????“do“:?6?“const“:?7?“var“:?8?“call“:?9?“procedure“:?10}

算符和界符及種別編碼
Punctuation_marks?=?{“+“:?11?“-“:?12?“*“:?13?“/“:?14?“odd“:?15?“=“:?16?“<>“:?17?“<“:?18?“>“:?19
?????????????????????“<=“:?20?“>=“:?21?“:=“:?22?“（“:?23?“）“:?24?“.“:?25?““:?26?“;“:?27}

常數的種別編碼為28，標識符的種別編碼為29，非法字符的種別編碼為30
‘‘‘
#?導入詞法分析的程序
from?PL0_System_Lex?import?*

#?由于實驗二的特殊性，單獨把i（id）當做保留字處理
Static_word[“i“]?=?0

#?i?+?-?*?、?（?）?num的種別編碼
Lab2_word?=?[0?11?12?13?14?23?24?28]

#?出錯標志
Err?=?0

#?位置標志
Index?=?0

#?算術表達式是否符合文法
Correct?=?“CorrectThe?arithmetic?expression?meets?the?grammatical?requirements!“
Error?=?“ErrorThe?arithmetic?expression?does?not?meet?the?grammatical?requirements!“


#?語法分析結果寫入文件
def?WriteFile（string）:
????fW?=?open（pathW?‘a‘）
????fW.write（string?+?“\n“）
????fW.close（）


#?開始正式語法分析前首先判斷該算術表達式中的各個字符以及首尾字符是否符合要求
def?First（）:
????index?=?0
????if?（Result_Lex[0][0]?in?[0?23?28]）?and?（Result_Lex[0][-1]?in?[0?24?28]）:
????????for?i?in?Result_Lex[:-2]:
????????????if?i?not?in?Lab2_word:
????????????????index?+=?1
????????????????break
????????????else:
????????????????continue
????else:
????????index?+=?1
????return?index


#?E→TE‘
def?E（）:
????global?Err
????if?Err?==?0:
????????T（）
????????E1（）


#?E‘→+TE‘|?-TE‘?|ε
def?E1（）:
????global?Err?Index
????if?Err?==?0?and?Index?!=?len（Result_Lex[0]）:
????????if?Result_Lex[0][Index]?in?[11?12]:
????????????Index?+=?1
????????????if?Index?!=?len（Result_Lex[0]）?-?1:
????????????????T（）
????????????????E1（）
????????????else:
????????????????Index?=?len（Result_Lex[0]）
????????elif?Result_Lex[0][Index]?!=?24:
????????????Err?=?1


#?T→FT‘
def?T（）:
????global?Err
????if?Err?==?0:
????????F（）
????????T1（）


#?T‘→*FT‘|?/FT‘?|ε
def?T1（）:
????global?Err?Index
????if?Err?==?0?and?Index?!=?len（Result_Lex[0]）:
????????if?Result_Lex[0][Index]?in?[13?14]:
????????????Index?+=?1
????????????if?Index?!=?len（Result_Lex[0]）?-?1:
????????????????F（）
????????????????T1（）
????????????else:
????????????????Index?=?len（Result_Lex[0]）
????????elif?Result_Lex[0][Index]?not?in?[11?12?24]:
????????????Err?=?1


#?F→（E）?|?id?|num
def?F（）:
????global?Err?Index
????if?Err?==?0:
????????if?Result_Lex[0][Index]?in?[0?28]:
????????????Index?+=?1
????????elif?Result_Lex[0][Index]?==?23:
????????????Index?+=?1
????????????E（）
????????????if?Result_Lex[0][Index]?!=?24:
????????????????Err?=?1

????????????Index?+=?1
????????else:
????????????Err?=?1


#?分析主程序
def?Analysis_Gs（）:
????global?Err?Index
????if?First（）?==?0:
????????F（）
????????while?Index?????????????if?Result_Lex[0][Index]?in?[11?12]:
????????????????E1（）
????????????elif?Result_Lex[0][Index]?in?[13?14]:
????????????????T1

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----
?????目錄???????????0??2020-06-23?12:59??璇硶鍒嗘瀽\
?????文件????????6148??2020-06-15?06:06??璇硶鍒嗘瀽\.DS_Store
?????文件?????????120??2020-06-15?06:06??__MACOSX\璇硶鍒嗘瀽\._.DS_Store
?????目錄???????????0??2020-06-23?12:59??璇硶鍒嗘瀽\TestLab2\
?????目錄???????????0??2020-06-23?12:59??璇硶鍒嗘瀽\__pycache__\
?????文件????????3784??2020-06-18?11:25??璇硶鍒嗘瀽\Lab_2.py
?????文件????????8152??2020-06-04?11:35??璇硶鍒嗘瀽\PL0_System_Lex.py
?????目錄???????????0??2020-06-23?12:59??璇硶鍒嗘瀽\Result_2\
?????目錄???????????0??2020-06-23?12:59??璇硶鍒嗘瀽\.idea\
?????文件???????????2??2020-06-04?17:34??璇硶鍒嗘瀽\TestLab2\demo6.txt
?????文件???????????7??2020-06-04?17:08??璇硶鍒嗘瀽\TestLab2\demo4.txt
?????文件???????????5??2020-06-04?17:21??璇硶鍒嗘瀽\TestLab2\demo5.txt
?????文件??????????16??2020-06-04?17:06??璇硶鍒嗘瀽\TestLab2\demo1.txt
?????文件??????????14??2020-06-18?11:53??璇硶鍒嗘瀽\TestLab2\demo2.txt
?????文件??????????25??2020-06-04?17:07??璇硶鍒嗘瀽\TestLab2\demo3.txt
?????文件????????4458??2020-06-04?11:40??璇硶鍒嗘瀽\__pycache__\PL0_System_Lex.cpython-37.pyc
?????文件?????????283??2020-06-18?11:56??璇硶鍒嗘瀽\Result_2\5.txt
?????文件????????1037??2020-06-18?11:55??璇硶鍒嗘瀽\Result_2\3.txt
?????文件?????????588??2020-06-18?11:54??璇硶鍒嗘瀽\Result_2\2.txt
?????文件?????????707??2020-06-18?11:52??璇硶鍒嗘瀽\Result_2\1.txt
?????目錄???????????0??2020-06-23?12:59??璇硶鍒嗘瀽\.idea\inspectionProfiles\
?????文件?????????284??2020-06-01?10:16??璇硶鍒嗘瀽\.idea\璇硶鍒嗘瀽.iml
?????文件?????????176??2020-06-01?10:16??璇硶鍒嗘瀽\.idea\.gitignore
?????文件???????10128??2020-06-19?01:47??璇硶鍒嗘瀽\.idea\workspace.xml
?????文件?????????276??2020-06-01?10:16??璇硶鍒嗘瀽\.idea\modules.xml
?????文件?????????289??2020-06-01?10:16??璇硶鍒嗘瀽\.idea\misc.xml
?????文件?????????174??2020-06-01?10:16??璇硶鍒嗘瀽\.idea\inspectionProfiles\profiles_settings.xml
?????文件?????????410??2020-06-01?10:16??璇硶鍒嗘瀽\.idea\inspectionProfiles\Project_Default.xml