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You do know that jQuery isn't a monad, right? That's the second time in this thread that you've called it one. Simplest demonstration that it isn't: try definin

You do know that jQuery isn't a monad, right? That's the second time in this thread that you've called it one. Simplest demonstration that it isn't: try defining join.

TheZenPsycho 13y ago
jquery-like. I never claimed that that jquery is a monad. I know it isn't. But also, I don't want to be one of those guys that throws around the word monad expecting everyone to understand what I'm talking about. as for defining "join", help me understand. How is jquery "add" not essentially that? And why pick the fmap,join formulation instead of the bind,return formulation of a monad?
- nbouscal 13y ago
  jQuery's add function has a few different formulations depending on what argument you pass, but it's basically either M a -> a -> M a (if you pass it an html string, an element, or a selector) or M a -> M a -> M a (if you pass it another jQuery object) where here M refers to the jQuery wrapper and the first argument refers to `this` (obviously these type signatures are an approximation since JavaScript doesn't really work this way). join is M (M a) -> M a, which is very different. The reason I picked join is because (in my view, anyway) it's the easiest demonstration of how jQuery is not a monad. There's no way to even get something of type M (M a) in jQuery, because the jQuery lifting operation is idempotent. The same exact problem exists with return, but I've found that people have a hard time seeing it with that example. The problem I have with you referring to jQuery as a monad, even by analogy, is that jQuery really really isn't a monad. It's only very loosely analogous, and that analogy is more likely to teach people the wrong things about monads rather than the right ones.
  - TheZenPsycho 13y ago
    Well that is a fair enough concern, and I notice I used the word "Monadic" to describe jquery carelessly, to mean "Monad-like" though that isn't really what "Monadic" means. For the case in hand though, you can get to almost but not quite really technically a monad, and still cure most of the nested callback headaches. One way I think about monads is they are a strategy for turning nested functions into sequentially composed functions. Which is, pretty much what we want, right?
    - nbouscal 13y ago
      I just don't think it's useful to use the word monad to describe the strategy you're suggesting. I'm not criticizing your suggestion, I just don't think it has anything to do with monads. More to the point, I don't understand why we (HN and the JS community at large) keep having this discussion. Coroutines have been around since the 60s. This is a solved problem.
      - TheZenPsycho 13y ago
        because you can't use coroutines in client-side javascript yet, without some backpiler, and people will disagree on what the proper reaction to that should be.

You do know that jQuery isn't a monad, right? That's the second time in this thread that you've called it one. Simplest demonstration that it isn't: try defining join.

TheZenPsycho 13y ago

jquery-like. I never claimed that that jquery is a monad. I know it isn't. But also, I don't want to be one of those guys that throws around the word monad expecting everyone to understand what I'm talking about. as for defining "join", help me understand. How is jquery "add" not essentially that? And why pick the fmap,join formulation instead of the bind,return formulation of a monad?

nbouscal 13y ago
jQuery's add function has a few different formulations depending on what argument you pass, but it's basically either M a -> a -> M a (if you pass it an html string, an element, or a selector) or M a -> M a -> M a (if you pass it another jQuery object) where here M refers to the jQuery wrapper and the first argument refers to `this` (obviously these type signatures are an approximation since JavaScript doesn't really work this way). join is M (M a) -> M a, which is very different. The reason I picked join is because (in my view, anyway) it's the easiest demonstration of how jQuery is not a monad. There's no way to even get something of type M (M a) in jQuery, because the jQuery lifting operation is idempotent. The same exact problem exists with return, but I've found that people have a hard time seeing it with that example. The problem I have with you referring to jQuery as a monad, even by analogy, is that jQuery really really isn't a monad. It's only very loosely analogous, and that analogy is more likely to teach people the wrong things about monads rather than the right ones.
- TheZenPsycho 13y ago
  Well that is a fair enough concern, and I notice I used the word "Monadic" to describe jquery carelessly, to mean "Monad-like" though that isn't really what "Monadic" means. For the case in hand though, you can get to almost but not quite really technically a monad, and still cure most of the nested callback headaches. One way I think about monads is they are a strategy for turning nested functions into sequentially composed functions. Which is, pretty much what we want, right?
  - nbouscal 13y ago
    I just don't think it's useful to use the word monad to describe the strategy you're suggesting. I'm not criticizing your suggestion, I just don't think it has anything to do with monads. More to the point, I don't understand why we (HN and the JS community at large) keep having this discussion. Coroutines have been around since the 60s. This is a solved problem.
    - TheZenPsycho 13y ago
      because you can't use coroutines in client-side javascript yet, without some backpiler, and people will disagree on what the proper reaction to that should be.