In https://Clara.io we identified that _.each() and other types of function-based helpers were incredibly slow (even lodash was slow) and we had to replace these constructs in performance critical areas with raw for-loops. Three.JS we also did this.
What problem does this solve? It seems to trade more-verbose code for being more performant in large datasets. That seems reasonable. But otherwise, in day-to-day code why would I use this?
The goal is to be less-verbose.
You are able to use tansducer-based functions (map, filter, ...) on any datastructure that is iterable. For me, performance is a bonus.
I do not know how this compares to a monad/monoid. If anyone can explain, please go ahead. Thx!
Monad/Monoid are a different category of things from transducers—think of them more like an interface than a thing. For instance, a basic model of Transducer is as follows
type Trans a b = forall r . (r -> b -> r) -> (r -> a -> r)
and it turns out that this is isomorphic to (e.g. an optimization of) the list Kleisli arrow
type KleiList a b = a -> [b]
and lists are monads. For a slightly different reason, this argumentation leads me to believe that Transducers ought to be monads via the Reader/List transformer stack. I haven't verified it, however.
Transducers could be monoids, too. You'd need to have two operations like so
zero :: Transducer a b
add :: Transducer a b -> Transducer a b -> Transducer a b
and perhaps there would be necessary restrictions on the choices of `a` and `b`. It's immediately obvious we could make this work if `a` and `b` were equal
zero :: Transducer a a
add :: Transducer a a -> Transducer a a -> Transducer a a
as this is now just the "identity" transducer and transducer composition which satisfy all the laws of monoid.
You are able to use transducers on any datastructure that implements the protocol. Which means usually implementing it yourself.
for/of solves this in JavaScript. I don't see the usability improvement this presents. I'm not being a naysayer. I hope I'm wrong here, I'm just asking.
> Time should be on the x-axis. Independent variables on the x-axis and dependent variables on the y.
The graph is correct - the independent variables in this case are the number of items in the array (the x axis) and the library being tested (each line).
The dependent variable in this case is time - which is why it is on the y axis.
