ISet<T> in spring4D

[Dave Novo 51]

I am a bit new to spring 4D, and am attempting to use ISet<T> as a replacement of the standard set of <type> in Delphi.

 

How do you easily check if an value is in a ISet<T>

 

The use case I have is with an enum. Where TEnumSet = set of enum;

 

In Delphi I would do 

 

if myEnumToCheckFor in MySet then .....

 

I had expected to see a method ISet<T>.Contains<T>:Boolean, or something along those lines, but I don't see anything. It seems like ISet<T> has lots of helpful methods for dealing with other sets, but I cannot find anything to check if an individual item is in the set. Of course, I can create a new set that contains 1 item and use that, but it seems overkill to do

 

presuming Myset:=ISet<some enum>

if MySet.InsersetsWith(TCollections.CreateSet([myenumTocheckFor])) do....

 

am I missing something?

 

note: sorry, I meant to put this in 3rd party, but somehow it ended up here. I cannot seem to find a way to move it to the 3rd party subforum.

Edited Sunday at 01:29 AM by Dave Novo
note about wrong forum

[pyscripter 694]

Inheritance Tree:

IEnumerable<T>

  IReadOnlyCollection<T>

   ICollection<T>

     ISet<T> 

 

  IEnumerable<T> has many functions including Contains:

    function Contains(const value: T): Boolean; overload;
    function Contains(const value: T; const comparer: IEqualityComparer<T>): Boolean; overload;
    function Contains(const value: T; const comparer: TEqualityComparison<T>): Boolean; overload;

 

[Dave Novo 51]

Oh thanks. I did not think to go all the way up to enumerable, as I am used to that interface just being for enumeration. I will investigate that further....

[Stefan Glienke 2016]

FWIW if your type is an enum already it makes no sense to use ISet<T> because you can use the enum set. ISet<T> is for types that are no enums, such as string for example.

[Dave Novo 51]

The reason I was thinking of using ISet is just that Delphi is very verbose:

 

if myEnum in myset then

 

is not so bad but

 

if  [enum1,enum2] * myset <> [] then

 

is obscure and if you dont use this syntax frequently you are constantly reminding yourself what the intention was, particularly for more complex set operations. I feel that

 

if mySet.DoesNotContainAny([enum1,enum2]) then

 

 is much easier to understand the intention. Not as performant of course. 

Edited Monday at 05:47 AM by Dave Novo

[David Heffernan 2353]

Sorry, please delete

Edited Monday at 08:14 PM by David Heffernan