Objects instead of references

The ABAP syntax for working with tables is really good. But the syntax for working with references is crap.

Many times, for the sake of efficiency, I need to mix references and tables. And I never found an easy way to do that in ABAP.

For example, I want to have a table with thousands of city names and for each city I want to have a table of dozens of places. Then, for a given city I want to get the list of places and do some actions on that data (sorting, removing, changing, etc). Notice that it is not a good idea to have just one table with both cities and places because each sublist operation would have a big penalty because of the big size of the full table.

In python it is so easy:


cities = {'Porto':['Casa da Musica','Serralves','Torre dos Clerigos'],
'New York': ['Empire State Building','Central Park'] }

#print the sorted list of places in Porto
cities['Porto'].sort()
print cities['Porto']


In ABAP I find myself using objects because the resulting syntax is cleaner. It looks something like this:


TYPES:
BEGIN OF t_place,
place TYPE char30,
END OF t_place.

TYPES:
t_tab_places TYPE TABLE OF t_place.

CLASS place_obj DEFINITION.
PUBLIC SECTION.
DATA places_table TYPE t_tab_places.
METHODS add_place IMPORTING place_name TYPE char30.
PRIVATE SECTION.
ENDCLASS. "place DEFINITION

CLASS place_obj IMPLEMENTATION.
METHOD add_place.
DATA ls_place TYPE t_place.
ls_place-place = place_name.
APPEND ls_place TO places_table.
ENDMETHOD.
ENDCLASS.

TYPES:
BEGIN OF t_city,
city_name TYPE char20,
places_ref TYPE REF TO place_obj,
END OF t_city.

DATA:
gt_city TYPE HASHED TABLE OF t_city WITH UNIQUE KEY city_name,
gs_city TYPE t_city,
gs_place TYPE t_place.

DATA oref TYPE REF TO place_obj.

START-OF-SELECTION.
gs_city-city_name = 'Porto'.
CREATE OBJECT oref.
gs_city-places_ref = oref.
CALL METHOD oref->add_place( 'Torre dos Clerigos' ).
CALL METHOD oref->add_place( 'Casa da Musica' ).
CALL METHOD oref->add_place( 'Serralves' ).
INSERT gs_city INTO TABLE gt_city.

gs_city-city_name = 'New York'.
CREATE OBJECT oref.
gs_city-places_ref = oref.
CALL METHOD oref->add_place( 'Empire State Building' ).
CALL METHOD oref->add_place( 'Central Park' ).
INSERT gs_city INTO TABLE gt_city.

READ TABLE gt_city INTO gs_city WITH KEY city_name = 'Porto'.
IF sy-subrc = 0.
oref = gs_city-places_ref.
SORT oref->places_table BY place.
LOOP AT oref->places_table INTO gs_place.
WRITE: / gs_city-city_name, gs_place-place.
ENDLOOP.


But it's still far from perfect. Dear lazy web, is there a better way?