How to build an Array with Bison/Yacc and a Recursive Rule

With Bison, I figured out how to get everything into one long string as follows:

arg_list:
    WORD arg_list { strcat( $1, "IFS" ); $$ = strcat($1, $2); }  |
    WORD
    ;

and:

WORD arg_list { printf("%s, %s\n", $1, $2); }

But the problem is that I will then have to split up $2 in the second rule again to parse it. Is there a way to populate an array instead of just using concatenation? Am I going about this the wrong way?

If I need to build something like a linked list that could make sense, just not sure what would be the proper way to bind to arg_list, and then clean up the memory.

From stackoverflow

• If you have an array type with a push_front operation, this is trivially:

  arg_list:
      WORD arg_list { $$ = $2.push_front($1); }
      WORD { $$ = new Array<string>($1); }
  

  without that, it requires more work. You can use a vector and add the strings on the end (which will be in the reversed order). Or you can use a linked list (which is easier if you're using straight C):

  arg_list:
      WORD arg_list { $$ = malloc(sizeof(struct list_elem));
                      $$->next = $2;
                      $$->val = $1; }
      WORD          { $$ = malloc(sizeof(struct list_elem));
                      $$->next = 0;
                      $$->val = $1; }
  

  Kyle Brandt : This is all straight C, the second one mostly makes sense, but I haven't gotten to the part where $$ has members, know what I might google exactly to find that?

  Kyle Brandt : Got your second example working, thank you.

  Chris Dodd : $$ is just a variable of the type declared in the %type declaration of this rule, or of YYSTYPE if there is no %type declaration. Commonly, that will be a 'struct list *' for arg_list, so '$$->next' and '$$->val' will be elements of the pointed-to list object. In the C++ case its much more complex, depending on how you've defined things with potential references and whatnot.