boost-spirit-x3

问题 For the development of Spirit X3 parser I want to use semantic actions(footnote 1). It is important for me to be in control of how to store attributes into STL containers. This question is about how to control that the parser attribute: _attr( ctx ) match the rule type: _val( ctx ) so that it can be assigned properly. Maybe this question boils down to how to apply the undocumented transform_attribute feature. But please read with me to see if that is actually the thing that solves it for me

问题 I'm trying to write an expression parser with boost spirit x3. I based my new code on old code that I written years ago (and worked well) with Spirit 2.x (qi). The core of my code is: //Make new rule(s) for expression auto term = factor >> *(('*' >> factor) | ('/' >> factor)); auto expression = term >> *(('+' >> term) | ('-' >> term)); auto group = '(' >> expression >> ')'; auto factor = lexeme["double_"] | group; string s="12.4 + 3.2"; auto first = s.begin(); auto last = s.end(); bool r = x3

问题 I'm trying to write an expression parser with boost spirit x3. I based my new code on old code that I written years ago (and worked well) with Spirit 2.x (qi). The core of my code is: //Make new rule(s) for expression auto term = factor >> *(('*' >> factor) | ('/' >> factor)); auto expression = term >> *(('+' >> term) | ('-' >> term)); auto group = '(' >> expression >> ')'; auto factor = lexeme["double_"] | group; string s="12.4 + 3.2"; auto first = s.begin(); auto last = s.end(); bool r = x3

问题 PREFACE: I am asking this question because for some reason I can not get my code to compile. I just want to know whether an incorrect understanding of spirit::x3 is the cause or not Hello, I'd just like to verify something; is the following the correct way (at least technically) of defining rules for a large set of heavily recursive parsers? So for each parser, I do the following operations: // This is for reference only, it greatly simplifies the process of defining attributes. template

问题 I need to build an abstract syntax tree from mathematical expression that I later need to link domain specific objects together as a calculation tree. I found the expression parser library https://github.com/hmenke/boost_matheval as an excellent starting point. In my use case I need to have support for ternary conditional expressions condition ? true_exp : false_exp . As of now the parser is able to parse expressions such as 1 + (2 + abs(x)) or min(x,1+y) . However I would need to have syntax

问题 I need to create a parser for quoted strings for my custom language that will also properly handle escape sequences, which includes allowing escaped quotes within the string. This is my current string parser: x3::lexeme[quote > *(x3::char_ - quote) > quote] where quote is just a constant expression for '"' . It does no escape sequence handling whatsoever. I know about boost::spirit::classic::lex_escape_ch_p , but I've no idea how to use that with the boost::spirit::x3 tools (or in general).

问题 The boost::spirit::x3 error handling utilities allow for the user to choose what is shown to the user when an expectation failure occurs. This, however, does not seem to be the case for the line number portion of the message, which is exactly what I'd like to modify. So instead of it printing out In line 1: etc. I would like to print some other message in it's place with the same line number info. Anyone know how I could do that, or if it is even modifiable in the first place? EDIT: Here's

问题 I am trying to parse the following struct: struct Selector { std::string element; std::string id; std::vector<std::string> classes; }; This struct is used to parse selectors in the form element#id.class1.class2.classn . These selectors always start with 1 or no elements, could contain 1 or no ids, and could contain 0 to n classes. This gets even more complicated though, because classes and id can appear in any order, so the following selectors are all valid: element#id.class1 , .class1#id

问题 I am trying to parse the following struct: struct Selector { std::string element; std::string id; std::vector<std::string> classes; }; This struct is used to parse selectors in the form element#id.class1.class2.classn . These selectors always start with 1 or no elements, could contain 1 or no ids, and could contain 0 to n classes. This gets even more complicated though, because classes and id can appear in any order, so the following selectors are all valid: element#id.class1 , .class1#id

问题 I am having a weird problem with boost spirit X3 (v1.69) in combination with MS VS2017. I am getting compiling errors in well formed structures. When I use the same code block in gcc and clang through Coliru or Wandbox, the source compiles and everything goes right. But when I use that same code in VS 2017, compiling errors appears until I comment an 'omit' sentence. Please, any help with this? #include <vector> #include <iostream> #include <boost/spirit/home/x3.hpp> #include <boost/fusion