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delphiloopsenumeration

Loop through irregular enumeration in Delphi

1) Does anyone know if it is possible to loop through an irregular enumeration in Delphi (XE)?

Looping over a normal enumeration is ok. From Delphi Basics:

var
  suit : (Hearts, Clubs, Diamonds, Spades);
begin
// Loop 3 times
For suit := Hearts to Diamonds do
   ShowMessage('Suit = '+IntToStr(Ord(suit)));
end;

But, if 'suit' instead is declared as

var
  suit : (Hearts=1, Clubs, Diamonds=10, Spades);

it loops 10 times. Not suprising, but I would like to loop 3. The only solution I've found so far is converting an enumeration to a set and use the 'for ... in'-loop like on delphi.about.com.

So, if answer to question 1) is no, then:
2) How to convert from enumeration to set in Delphi?

The context I am using it in is a component array of edit-boxes (TEdit) that has an irregular numbering (edit1, edit5, edit7, edit3, ...). While it is possible to reorder all the edit-boxes, it removes the reason of using enumeration as a flexible way to allow addition of an edit-box in the middle of the enumeration.

Solution

  • I do not have a Delphi compiler at hand right now, but I tink that gabr's approach can be rather significantly improved by doing

    type
  TSuit = (Hearts = 1, Clubs, Diamonds = 10, Spades);

const
  Suits: array[0..3] of TSuit = (Hearts, Clubs, Diamonds, Spades);

    Who knows, maybe it doesn't even compile.