WITH statement for structures - abap

Question

In some languages there exist syntax to simplify method and property access of a single object. As an example from VB.NET:
With foo
.bar()
.reset(true)
myVar = .getName()
End With
Or as Jagger points out, in Pascal:
With myBookRec do
Begin
Title := 'Some Book';
Author := 'Victor John Saliba';
ISBN := '0-12-345678-9';
Price := 25.5;
End;
Now I often find myself setting a ton of properties on a given structure. Take for instance the classic case of setting a field catalog:
LOOP AT lt_fieldcat INTO ls_fieldcat.
CASE ls_fieldcat-fieldname.
WHEN 'COLUMN_1'.
ls_fieldcat-edit = ''.
WHEN 'COLUMN_2'.
ls_fieldcat-edit = 'X'.
ls_fieldcat-outputlen = 20.
WHEN 'COLUMN_3'.
ls_fieldcat-edit = abap_true.
ls_fieldcat-drdn_hndl = '2'.
ls_fieldcat-drdn_alias = 'X'.
ls_fieldcat-outputlen = 5.
ls_fieldcat-col_pos = 1.
ls_fieldcat-scrtext_s = text-f01.
ls_fieldcat-scrtext_m = text-f01.
ls_fieldcat-scrtext_l = text-f01.
ENDCASE.
MODIFY lt_fieldcat FROM ls_fieldcat.
ENDLOOP.
Is there any way to replicate WITH-like functionality in ABAP?
If not, is there a better way to replicate this behaviour?
I've actually considered replicating the "return this" method daisy chain for a field catalog class. This seems like a WITH-alternative but I'm not entirely sold on its usefulness, given that you'd have to maintain a class for every structure.
ls_fieldcat = zcl_fieldcat=>new( ls_fieldcat )->edit('')->outputlen(20)->col_post(1)->get().

Answer 1

I don't think the daisy-chain approach is that useful - it's not much easier to read, and if anything goes wrong, it's awfully hard to debug. Personally, I'd probably use a "multi-setter" with multiple optional attributes:
lr_my_field->set_attributes( edit = abap_true
title = 'foo'
* ...
bar = 'baz' ).
That being said, I don't have a problem with the code in your question at all. Clearly readable, simple data handling. Just put it away into a method named PREPARE_FIELDCATALOG and everone knows what to expect.

Answer 2

With the new ABAP syntax you could simplify your code a bit with VALUE #( ... ) statement (or VALUE #( BASE ls_fieldcat ...) for modifying a structure with already assigned fields) which can be used for emulating WITH in ABAP. Not a perfect solution, especially if one has a CASE structure like yours but surely neat for initalizing a structured variable.
LOOP AT lt_fieldcat INTO ls_fieldcat.
CASE ls_fieldcat-fieldname.
WHEN 'COLUMN_1'.
ls_fieldcat = VALUE #(
BASE ls_fieldcat
edit = ''
).
WHEN 'COLUMN_2'.
ls_fieldcat = VALUE #(
BASE ls_fieldcat
edit = 'X'
outputlen = 20
).
WHEN 'COLUMN_3'.
ls_fieldcat = VALUE #(
BASE ls_fieldcat
edit = abap_true
drdn_hndl = '2'
drdn_alias = 'X'
outputlen = 5
col_pos = 1
scrtext_s = text-f01
scrtext_m = text-f01
scrtext_l = text-f01
).
ENDCASE.
MODIFY lt_fieldcat FROM ls_fieldcat.
ENDLOOP.