使用动态令牌进行PLY

时间:2018-10-14 15:59:33

标签: python python-3.x ply

我正在编写一个程序,可以解析用.tex文件编写的数学论文。这是我想要的:

该程序应能够检测数学纸中的开始,结尾,部分,小节,子小节,定理,引理,定义,猜想,推论,命题,练习,符号和示例,而忽略其余内容产生摘要。

程序一开始应该保留所有字符,直到到达令牌MT。在这种情况下,控制杆应保留令牌并进入ig模式。然后它应该忽略所有字符,除非它检测到一个定理/引理/定义/猜想/推论/示例/练习/记号/命题,在这种情况下,它将暂时进入INITIAL模式并保留它或(sub / subsub )部分,则应暂时进入sec模式。

\newtheorem{<name>}{<heading>}[<counter>]\newtheorem{<name>}[<counter>]{<heading>}分别被检测为TH ptext THCC ptext THC ptextTH ptext THCS ptext THSC ptext THC,其中ptext是一堆TEXT

import sys
import logging
from ply.lex import TOKEN

if sys.version_info[0] >= 3:
    raw_input = input

tokens = (
'BT', 'BL', 'BD', 'BCONJ', 'BCOR', 'BE', 'ET', 'EL', 'ED', 'ECONJ', 'ECOR', 'EE', 'SEC', 'SSEC', 'SSSEC', 'ES', 'TEXT','ITEXT','BIBS','MT','BN','EN','BEXE','EEXE','BP','EP','TH','THCS','THSC','THCC','THC',
)

states = (('ig', 'exclusive'), ('sec', 'exclusive'), ('th', 'exclusive'), ('tht','exclusive'),('thc','exclusive'))

logging.basicConfig(
    level = logging.DEBUG,
    filename = "lexlog.txt",
    filemode = "w",
    format = "%(filename)10s:%(lineno)4d:%(message)s"
)
log = logging.getLogger()

th_temp = ''
thn_temp = ''
term_dic = {'Theorem':'','Lemma':'','Corollary':'','Definition':'','Conjecture':'','Example':'','Exercise':'','Notation':'','Proposition':''}
idb_list = ['','','','','','','','','']
ide_list = ['','','','','','','','','']
bb = r'\\begin\{'
eb = r'\\end\{'
ie = r'\}'
def finalize_terms():
    global idb_list
    global ide_list
    if term_dic['Theorem'] != '':
        idb_list[0] = bb + term_dic['Theorem'] + ie
        ide_list[0] = eb + term_dic['Theorem'] + ie
    if term_dic['Lemma'] != '':
        idb_list[1] = bb + term_dic['Lemma'] + ie
        ide_list[1] = eb + term_dic['Lemma'] + ie
    if term_dic['Corollary'] != '':
        idb_list[2] = bb + term_dic['Corollary'] + ie
        ide_list[2] = eb + term_dic['Corollary'] + ie
    if term_dic['Definition'] != '':
        idb_list[3] = bb + term_dic['Definition'] + ie
        ide_list[3] = eb + term_dic['Definition'] + ie
    if term_dic['Conjecture'] != '':
        idb_list[4] = bb + term_dic['Conjecture'] + ie
        ide_list[4] = eb + term_dic['Conjecture'] + ie
    if term_dic['Example'] != '':
        idb_list[5] = bb + term_dic['Example'] + ie
        ide_list[5] = eb + term_dic['Example'] + ie
    if term_dic['Exercise'] != '':
        idb_list[6] = bb + term_dic['Exercise'] + ie
        ide_list[6] = eb + term_dic['Exercise'] + ie
    if term_dic['Notation'] != '':    
        idb_list[7] = bb + term_dic['Notation'] + ie
        ide_list[7] = eb + term_dic['Notation'] + ie
    if term_dic['Proposition'] != '':
        idb_list[8] = bb + term_dic['Proposition'] + ie
        ide_list[8] = eb + term_dic['Proposition'] + ie
    print(idb_list)
    print(ide_list)

以下是一些解析功能:

def t_TH(t):
    r'\\newtheorem\{'
    t.lexer.begin('th')
    return t

def t_th_THCS(t):
    r'\}\['
    t.lexer.begin('thc')
    return t

def t_tht_THC(t):
    r'\}'
    if term_dic.has_key(thn_temp) == False:
        print(f"{thn_temp} is unknown!")
    elif len(th_temp) == 0:
        print(f"No abbreviation for {thn_temp} is found!")
    else:
        term_dic[thn_temp] = th_temp
        print(f"The abbreviation for {thn_temp} is {th_temp}!")
    th_temp = ''
    thn_temp = ''
    t.lexer.begin('INITIAL')
    return t

def t_th_THCC(t):
    r'\}\{'
    t.lexer.begin('tht')
    return t

def t_thc_THSC(t):
    r'\]\{'
    t.lexer.begin('tht')
    return t

@TOKEN(idb_list[0])
def t_ig_BT(t):
    t.lexer.begin('INITIAL')
    return t

@TOKEN(ide_list[0])
def t_ET(t):
    t.lexer.begin('ig')
    return t

def t_INITIAL_sec_thc_TEXT(t):
    r'[\s\S]'
    return t

def t_th_TEXT(t):
    r'[\s\S]'
    th_temp = th_temp + t.value()
    return t

def t_tht_TEXT(t):
    r'[\s\S]'
    thn_temp = thn_temp + t.value()
    return t

def t_ig_ITEXT(t):
    r'[\s\S]'
    pass

import ply.lex as lex
lex.lex(debug=True, debuglog = log)

以下是错误:     ERROR: /Users/CatLover/Documents/Python_Beta/TexExtractor/texlexparse.py:154: No regular expression defined for rule 't_ET'

我不知道为什么使用@TOKEN为't_ET'等定义的正则表达式不起作用。

1 个答案:

答案 0 :(得分:1)

Ply是解析器 generator 。它接受您的解析器/词法分析器描述,并从中编译一个解析器/词法分析器。您无法在解析过程中更改语言说明。

在这种情况下,您最好编写流式(“在线”)扫描仪。但是,如果要使用Ply,最好不要尝试修改语法以忽略部分输入。只需解析整个输入并忽略您不感兴趣的部分。您可能会发现代码更简单。