dungeon_feature_type trap_category(trap_type type);

    switch (this->type)

    return trap_category(type);
}
dungeon_feature_type trap_category(trap_type type)
{
    switch (type)

    const bool known = strip_tag(s, "known");

    feature_spec fspec(-1, weight);

    feature_spec fspec(known ? 1 : -1, weight);

        if (f.feat >= 0)

        if (f.trap >= 0)
        {
            // f.feat == 1 means trap is generated known.
            if (f.feat == 1)
                return trap_category(static_cast<trap_type>(f.trap));
            else
                return (DNGN_UNDISCOVERED_TRAP);
        }
        else if (f.feat >= 0)

        else if (f.trap >= 0)
            return (DNGN_UNDISCOVERED_TRAP);

        if (f.feat >= 0)

        if (f.trap >= 0)
        {
            const trap_type trap =
                (f.trap == TRAP_INDEPTH)
                    ? random_trap_for_place(place.level_number)
                    : static_cast<trap_type>(f.trap);
            place_specific_trap(where, trap);
            // f.feat == 1 means trap is generated known.
            if (f.feat == 1)
                grd(where) = trap_category(trap);
        }
        else if (f.feat >= 0)

        else if (f.trap >= 0)
        {
            const trap_type trap =
                (f.trap == TRAP_INDEPTH)
                    ? random_trap_for_place(place.level_number)
                    : static_cast<trap_type>(f.trap);
            place_specific_trap(where, trap);
        }

          If you want a trap to start out known to the player, add "known"
          to the trap name:
          KFEAT: A = known needle trap