gbresearch / axe Goto Github PK

convert_iterator (and e.g., r_ucase and other converting rules) assume that the iterator type is a C++ iterator, and not a const char*.
This means parsing rules expect an std::string or other container, and std::string_view will case a compilation error.

Hi,
I like the library but the documentation does not show how to add semantic elements to the parse rules. Since there's no wiki, i'm asking here.

The documentation says that there is a Data element of the result (that we can fetch using the get_as<> function), which I think can be used but my question how can I define the semantic element so I can build an AST using that data element?. Yacc has $$, $1, $2... to do this, so does axe have an equivalent? For instance how to do something like the following (if possible):

struct value{
  int     intVal;
  double  doubleVal;  
}
auto number = double_ >>[](auto a, auto b){ $$ = value{ -1, atof(*a)}; }
            | _int;   >>[](auto a, auto b){ $$ = value{ atoi(*a), -1.0}; }

auto expr = (number & '+' & number )  >> [](auto a, auto b){
   if ($1.intVal< 0) 
      $$ = value{-1,  $1.doubleVal + ($2.intVal < 0 ?  $2.doubleVal < 0 :  $2.intVal)};
   else 
      $$ = value{$1.intVal+ ($2.intVal < 0 ?  $2.doubleVal < 0 :  $2.intVal)};
};

Thanks

Severity Code Description Project File Line Suppression State
Error C2386 'parse_tree_result_t': a symbol with this name already exists in the current scope UnrealTable C:\Users\foo\Documents\Unreal Projects\AXE\include\axe_composite.h 109

... so I really like the project... but IDK... sorta blocked here. It twiggs many buttons that make me happy, tho.