I seem to be experiencing some mental block with Boost Spirit I just cannot get by. I have a fairly simple grammar I need to handle, where I would like to put the values into a struct, that contains a std::map<> as one of it's members. The key names for the pairs are known up front, so that only those are allowed. There could be one to many keys in the map, in any order with each key name validated via qi.
The grammar looks something like this, as an example.
test .|*|<hostname> add|modify|save ( key [value] key [value] ... ) ;
//
test . add ( a1 ex00
a2 ex01
a3 "ex02,ex03,ex04" );
//
test * modify ( m1 ex10
m2 ex11
m3 "ex12,ex13,ex14"
m4 "abc def ghi" );
//
test 10.0.0.1 clear ( c1
c2
c3 );
In this example the keys for “add” being a1, a2 and a3, likewise for “modify” m1, m2, m3 and m4 and each must contain a value. For “clear” the keys of the map c1, c2 and c3 may not contain a value. Also, let's say for this example you can have up to 10 keys (a1 ... a11, m1 ... m11 and c1 ... c11) any combination of them could be used, in any order, for their corresponding action. Meaning that you cannot use the known key cX for the "add" or mX for "clear"
The structure follows this simple pattern
//
struct test
{
std::string host;
std::string action;
std::map<std::string,std::string> option;
}
So from the above examples, I would expect to have the struct contain ...
// add ...
test.host = .
test.action = add
test.option[0].first = a1
test.option[0].second = ex00
test.option[1].first = a2
test.option[1].second = ex01
test.option[2].first = a3
test.option[2].second = ex02,ex03,ex04
// modify ...
test.host = *
test.action = modify
test.option[0].first = m1
test.option[0].second = ex10
test.option[1].first = m2
test.option[1].second = ex11
test.option[2].first = m3
test.option[2].second = ex12,ex13,ex14
test.option[2].first = m3
test.option[2].second = abc def ghi
// clear ...
test.host = *
test.action = 10.0.0.1
test.option[0].first = c1
test.option[0].second =
test.option[1].first = c2
test.option[1].second =
test.option[2].first = c3
test.option[2].second =
I can get each indivudal part working, standalone, but I cannot seem to them working together. For example I have the host and action working without the map<>.
I’ve adapted a previously posted example from Sehe (here) trying to get this to work (BTW: Sehe has some awesome examples, which I’ve been using as much as the documentation).
Here is an excerpt (obviously not working), but at least shows where I’m trying to go.
namespace ast {
namespace qi = boost::spirit::qi;
//
using unused = qi::unused_type;
//
using string = std::string;
using strings = std::vector<string>;
using list = strings;
using pair = std::pair<string, string>;
using map = std::map<string, string>;
//
struct test
{
using preference = std::map<string,string>;
string host;
string action;
preference option;
};
}
//
BOOST_FUSION_ADAPT_STRUCT( ast::test,
( std::string, host )
( std::string, action ) )
( ast::test::preference, option ) )
//
namespace grammar
{
//
template <typename It>
struct parser
{
//
struct skip : qi::grammar<It>
{
//
skip() : skip::base_type( text )
{
using namespace qi;
// handle all whitespace (" ", , ...)
// along with comment lines/blocks
//
// comment blocks: /* ... */
// // ...
// -- ...
// # ...
text = ascii::space
| ( "#" >> *( char_ - eol ) >> ( eoi | eol ) ) // line comment
| ( "--" >> *( char_ - eol ) >> ( eoi | eol ) ) // ...
| ( "//" >> *( char_ - eol ) >> ( eoi | eol ) ) // ...
| ( "/*" >> *( char_ - "*/" ) >> "*/" ); // block comment
//
BOOST_SPIRIT_DEBUG_NODES( ( text ) )
}
//
qi::rule<It> text;
};
//
struct token
{
//
token()
{
using namespace qi;
// common
string = '"' >> *("" >> char_ | ~char_('"')) >> '"';
identity = char_("a-zA-Z_") >> *char_("a-zA-Z0-9_");
real = double_;
integer = int_;
//
value = ( string | identity );
// ip target
any = '*';
local = ( char_('.') | fqdn );
fqdn = +char_("a-zA-Z0-9.\-" ); // consession
ipv4 = +as_string[ octet[ _pass = ( _1 >= 0 && _1 <= 255 ) ] >> '.'
>> octet[ _pass = ( _1 >= 0 && _1 <= 255 ) ] >> '.'
>> octet[ _pass = ( _1 >= 0 && _1 <= 255 ) ] >> '.'
>> octet[ _pass = ( _1 >= 0 && _1 <= 255 ) ] ];
//
target = ( any | local | fqdn | ipv4 );
//
pair = identity >> -( attr( ' ' ) >> value );
map = pair >> *( attr( ' ' ) >> pair );
list = *( value );
//
BOOST_SPIRIT_DEBUG_NODES( ( string )
( identity )
( value )
( real )
( integer )
( any )
( local )
( fqdn )
( ipv4 )
( target )
( pair )
( keyval )
( map )
( list ) )
}
//
qi::rule<It, std::string()> string;
qi::rule<It, std::string()> identity;
qi::rule<It, std::string()> value;
qi::rule<It, double()> real;
qi::rule<It, int()> integer;
qi::uint_parser<unsigned, 10, 1, 3> octet;
qi::rule<It, std::string()> any;
qi::rule<It, std::string()> local;
qi::rule<It, std::string()> fqdn;
qi::rule<It, std::string()> ipv4;
qi::rule<It, std::string()> target;
//
qi::rule<It, ast::map()> map;
qi::rule<It, ast::pair()> pair;
qi::rule<It, ast::pair()> keyval;
qi::rule<It, ast::list()> list;
};
//
struct test : token, qi::grammar<It, ast::test(), skip>
{
//
test() : test::base_type( command_ )
{
using namespace qi;
using namespace qr;
auto kw = qr::distinct( copy( char_( "a-zA-Z0-9_" ) ) );
// not sure how to enforce the "key" names!
key_ = *( '(' >> *value >> ')' );
// tried using token::map ... didn't work ...
//
add_ = ( ( "add" >> attr( ' ' ) ) [ _val = "add" ] );
modify_ = ( ( "modify" >> attr( ' ' ) ) [ _val = "modify" ] );
clear_ = ( ( "clear" >> attr( ' ' ) ) [ _val = "clear" ] );
//
action_ = ( add_ | modify_ | clear_ );
/* *** can't get from A to B here ... not sure what to do *** */
//
command_ = kw[ "test" ]
>> target
>> action_
>> ';';
BOOST_SPIRIT_DEBUG_NODES( ( command_ )
( action_ )
( add_ )
( modify_ )
( clear_ ) )
}
//
private:
//
using token::value;
using token::target;
using token::map;
qi::rule<It, ast::test(), skip> command_;
qi::rule<It, std::string(), skip> action_;
//
qi::rule<It, std::string(), skip> add_;
qi::rule<It, std::string(), skip> modify_;
qi::rule<It, std::string(), skip> clear_;
};
...
};
}
I hope this question isn't too ambiguous and if you need a working example of the problem, I can certainly provide that. Any and all help is greatly appreciated, so thank you in advance!
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