5 ms·

As someone who does not work with Javascript, I'm shocked that any language would have sets and not support these three operations.

Aardwolf 3y ago
C++ sets didn't even support 'contains' in the past
- nyrikki 3y ago
  C++ 'sets' are ordered mutable binary search trees in most implementations. Not the ties and hashtables of other languages. With strict weak ordering, you really only have the ordering of to elements. Ada took care of that polysemy between ordered and hash sets a long time ago. But ya it took them to long to implement 'contains', but JavaScript requiring ordered sets while allowing multiple implementation details complicated it IMHO. Had they chosen a structure vs a time complexity it would have been easier to extend. https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Set https://developer.mozilla.org/en-US/docs/Web/JavaScript/Refe...
  - bagels 3y ago
    Thankfully unordered_set is also available
    - nyrikki 3y ago
      Yes, that was one of the big reasons to move to C++11 where I was at the time.
- Calavar 3y ago
  That's just objectively untrue. C++ sets have always supported membership testing. bool set_contains_x = set.find(x) != set.end();
  - Aardwolf 3y ago
    I know that, but that's a rather elaborate way of doing the main thing sets do, and you have to repeat the name of the set twice. Fortunately C++20 added set.contains(x). Of course set.count(x) also already existed but some would prefer set.find(x) != set.end() anyway for <reasons>, and it's the fault of the language's design to cause such opinions in the first place imho.
  - qarl 3y ago
    I hate to be pedantic, but since you started it: That is not a contains() function. That is a search followed by a test for not not-found.
    - Calavar 3y ago
      That's a valid distinction for a vector or a list. For a set, contains and search are one and the same.
      - qarl 3y ago
        No, they are not the same thing. They are logically equivalent, which is not the same thing as same thing. 1+3 is logically equivalent to 4, but they are not the same. As just one example, the former contains an operation.
BurningFrog 3y ago
Yeah, it seems like something you can code up in an afternoon.

Aardwolf 3y ago

C++ sets didn't even support 'contains' in the past

nyrikki 3y ago
C++ 'sets' are ordered mutable binary search trees in most implementations. Not the ties and hashtables of other languages. With strict weak ordering, you really only have the ordering of to elements. Ada took care of that polysemy between ordered and hash sets a long time ago. But ya it took them to long to implement 'contains', but JavaScript requiring ordered sets while allowing multiple implementation details complicated it IMHO. Had they chosen a structure vs a time complexity it would have been easier to extend. https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Set https://developer.mozilla.org/en-US/docs/Web/JavaScript/Refe...
- bagels 3y ago
  Thankfully unordered_set is also available
  - nyrikki 3y ago
    Yes, that was one of the big reasons to move to C++11 where I was at the time.
Calavar 3y ago
That's just objectively untrue. C++ sets have always supported membership testing. bool set_contains_x = set.find(x) != set.end();
- Aardwolf 3y ago
  I know that, but that's a rather elaborate way of doing the main thing sets do, and you have to repeat the name of the set twice. Fortunately C++20 added set.contains(x). Of course set.count(x) also already existed but some would prefer set.find(x) != set.end() anyway for <reasons>, and it's the fault of the language's design to cause such opinions in the first place imho.
- qarl 3y ago
  I hate to be pedantic, but since you started it: That is not a contains() function. That is a search followed by a test for not not-found.
  - Calavar 3y ago
    That's a valid distinction for a vector or a list. For a set, contains and search are one and the same.
    - qarl 3y ago
      No, they are not the same thing. They are logically equivalent, which is not the same thing as same thing. 1+3 is logically equivalent to 4, but they are not the same. As just one example, the former contains an operation.

BurningFrog 3y ago

Yeah, it seems like something you can code up in an afternoon.