SimpleParse 不显示结果树

Question

我正在研究 Google ProtoBuff，我试图在 python 中使用 SimpleParse 解析 proto 文件。

我正在使用带有 SimpleParse 的 EBNF 格式，它显示成功，但结果树中没有任何内容，不确定出了什么问题。任何帮助将不胜感激。

以下是语法文件：

  proto ::= ( message / extend / enum / import / package / option / ';' )*

    import ::= 'import' , strLit , ';'

    package ::= 'package' , ident , ( '.' , ident )* , ';'

    option ::= 'option' , optionBody , ';'

    optionBody ::= ident , ( '.' , ident )* , '=' , constant

    message ::= 'message' , ident , messageBody

    extend ::= 'extend' , userType , '{' , ( field / group / ';' )* , '}'

    enum ::= 'enum' , ident , '{' , ( option / enumField / ';' )* , '}'

    enumField ::= ident , '=' , intLit , ';'

    service ::= 'service' , ident , '{' , ( option / rpc / ';' )* , '}'

    rpc ::= 'rpc' , ident ,  '(' , userType , ')' , 'returns' , '(' , userType , ')' , ';'

    messageBody ::= '{' , ( field / enum / message / extend / extensions / group / option / ':' )* , '}'

    group ::= label , 'group' , camelIdent , '=' , intLit , messageBody

    field ::= label , type , ident , '=' , intLit , ( '[' , fieldOption , ( ',' , fieldOption )* , ']' )? , ';'

    fieldOption ::= optionBody / 'default' , '=' , constant

    extensions ::= 'extensions' , extension , ( ',' , extension )* , ';'

    extension ::= intLit , ( 'to' , ( intLit / 'max' ) )?

    label ::= 'required' / 'optional' / 'repeated'

    type ::= 'double' / 'float' / 'int32' / 'int64' / 'uint32' / 'uint64' / 'sint32' / 'sint64' / 'fixed32' / 'fixed64' / 'sfixed32' / 'sfixed64' / 'bool' / 'string' / 'bytes' / userType

    userType ::= '.'? , ident , ( '.' , ident )*

    constant ::= ident / intLit / floatLit / strLit / boolLit

    ident ::= [A-Za-z_],[A-Za-z0-9_]*

    camelIdent ::= [A-Z],[\w_]*

    intLit ::= decInt / hexInt / octInt

    decInt ::= [1-9],[\d]*

    hexInt ::= [0],[xX],[A-Fa-f0-9]+

    octInt ::= [0],[0-7]+

    floatLit ::= [\d]+ , [\.\d+]? 

    boolLit ::= 'true' / 'false'

    strLit ::= quote ,( hexEscape / octEscape / charEscape / [^\0\n] )* , quote

    quote ::= ['']

    hexEscape ::= [\\],[Xx],[A-Fa-f0-9]
    octEscape ::= [\\0]? ,[0-7]
    charEscape ::= [\\],[abfnrtv\\\?'']

这是我正在试验的python代码：

from simpleparse.parser import Parser
from pprint import pprint


protoGrammar = ""
protoInput = ""
protoGrammarRoot = "proto"

with open ("proto_grammar.ebnf", "r") as grammarFile:
    protoGrammar=grammarFile.read()

with open("sample.proto", "r") as protoFile:
    protoInput = protoFile.read().replace('\n', '')

parser = Parser(protoGrammar,protoGrammarRoot)

success, resultTree, newCharacter = parser.parse(protoInput)

pprint(protoInput)

pprint(success)

pprint(resultTree)

pprint(newCharacter)

这是我要解析的原始文件

message AmbiguousMsg {
  optional string mypack_ambiguous_msg = 1;
  optional string mypack_ambiguous_msg1 = 1;
}

我得到的输出为

1
[]
0

Answer 1

我是 Python 新手，但我想出了这个，虽然我不完全确定你的输出格式。希望这将为您指明正确的方向。随意修改下面的代码以满足您的要求。

#!/usr/bin/python
# (c) 2015 enthusiasticgeek for StackOverflow. Use the code in anyway you want but leave credits intact. Also use this code at your own risk. I do not take any responsibility for your usage - blame games and trolls will strictly *NOT* be tolerated. 
import re
#data_types=['string','bool','enum','int32','uint32','int64','uint64','sint32','sint64','bytes','string','fixed32','sfixed32','float','fixed64','sfixed64','double']

#function # 1
#Generate list of units in the brackets
#================ tokens based on braces ====================
def find_balanced_braces(args):
    parts = []
    for arg in args:
    if '{' not in arg:
        continue
    chars = []
    n = 0
    for c in arg:
        if c == '{':
            if n > 0:
                chars.append(c)
            n += 1
        elif c == '}':
            n -= 1
            if n > 0:
                chars.append(c)
            elif n == 0:
                parts.append(''.join(chars).lstrip().rstrip())
                chars = []
        elif n > 0:
            chars.append(c)
    return parts

#function # 2
#================ Retrieve Nested Levels ====================
def find_nested_levels(test, count_level):
 count_level=count_level+1
 level = find_balanced_braces(test)
 if not bool(level):
  return count_level-1
 else:
  return find_nested_levels(level,count_level)

#function # 3
#================ Process Nested Levels ====================
def process_nested_levels(test, count_level):
 count_level=count_level+1
 level = find_balanced_braces(test)
 print "===== Level = " + str(count_level) + " ====="
 for i in range(len(level)):
     #print level[i] + "\n"
     exclusive_level_messages = ''.join(level[i]).split("message")[0]
     exclusive_level_messages_tokenized = ''.join(exclusive_level_messages).split(";")
     #print  exclusive_level_messages + "\n"
     for j in range(len(exclusive_level_messages_tokenized)):
     pattern = exclusive_level_messages_tokenized[j].lstrip()
     print pattern
     #match = "\message \s*(.*?)\s*\{"+pattern
     #match_result = re.findall(match, level[i])
     #print match_result        
 print "===== End Level ====="
 if not bool(level):
  return count_level-1
 else:
  return process_nested_levels(level,count_level)
#============================================================
#=================================================================================
test_string=("message a{ optional string level-i1.l1.1 = 1 [default = \"/\"]; "
"message b{ required bool level-i1.l2.1 = 1; required fixed32 level-i1.l2.1 = 2; "
"message c{ required string level-i1.l3.1 = 1; } "
"} "
"} "
"message d{ required uint64 level-i2.l1.1 = 1; required double level-i2.l1.2 = 2; "
"message e{ optional double level-i2.l2.1 = 1; "
"message f{ optional fixed64 level-i2.l3.1 = 1; required fixed32 level-i2.l3.2 = 2; "
"message g{ required bool level-i2.l4.1 = 2; } "
"} "
"} "
"} "
"message h{ required uint64 level-i3.l1.1 = 1; required double level-i3.l1.2 = 2; }")

#Right now I do not see point in replacing \n with blank space
with open ("fileproto.proto", "r") as myfile:
   data=myfile.read().replace('\n', '\n')
print data

count_level=0
#replace 'data' in the following line with 'test_string' for tests
nested_levels=process_nested_levels([data],count_level)
print "Total count levels depth = " + str(nested_levels)
print "========================\n"

我的输出如下所示

// This defines protocol for a simple server that lists files.
//
// See also the nanopb-specific options in fileproto.options.

message ListFilesRequest {
    optional string path = 1 [default = "/"];
}

message FileInfo {
    required uint64 inode = 1;
    required string name = 2;
}

message ListFilesResponse {
    optional bool path_error = 1 [default = false];
    repeated FileInfo file = 2;
}


===== Level = 1 =====
optional string path = 1 [default = "/"]

required uint64 inode = 1
required string name = 2

optional bool path_error = 1 [default = false]
repeated FileInfo file = 2

===== End Level =====
===== Level = 2 =====
===== End Level =====
Total count levels depth = 1
========================

注意在print pattern 之后，如有必要，您可以通过将pattern 作为输入来进一步标记化。我用正则表达式评论了一个例子。