[GSoC] replacing op in c_expr

[Prathamesh Kulkarni <bilbotheelffriend at gmail dot com>]

I am having few issues replacing op in c_expr.
I thought of following possibilities:

a) create a new vec<cpp_token> vector new_code.
for each token in code
  {
    if token.type is not CPP_NAME
      new_code.safe_push (token);
    else
     {
        cpp_token new_token =
            ??? create new token of type CPP_NAME
                  with contents as name of operator ???
     }
  }

I tried to go this way, but am stuck with creating a new token type.
i started by:
cpp_token new_token = token;  // get same attrs as token.
CPP_HASHNODE (new_token.val.node.node)->ident.str = name of operator.
CPP_HASHNODE (new_token.val.node.node)->ident.len = len of operator name.
name of operator is obtained from opers[i] in parse_for.

however this does not work because I guess
 new_token = token, shallow copies
the token (default assignment operator, i didn't find an overloaded version).

b) create new struct c_expr_elem and use
vec<c_expr_elem> code, instead of vec<cpp_token> code;

sth like:
struct c_expr_elem
{
   enum c_expr_elem_type { ID, TOKEN };
   enum c_expr_elem_type type;

   union {
     cpp_token token;
     const char *id;
   };
};

while replacing op, compare token with op, and if it matches,
create a new c_expr_elem with type = ID, and id = name of operator.
This shall probably work, but shall require many changes to other parts
since we change c_expr::code.

I would like to hear any other suggestions.

Thanks,
Prathamesh.