[IshKebab]

I think JS's map/reduce/filter design is one of the worst ones out there actually - map has footguns with its extra arguments and everything gets converted to an array at the drop of a hat. Still, pipeline syntax probably won't help fix any of that.

[thdhhghgbhy]

I always thought JS map filter reduce felt quite nice, especially playing around with data in the REPL. Java maps with all the conversions back and forth to streams are clumsy.

[Timwi]

Well in JS you have to convert to arrays instead. You can't do `document.querySelectorAll(...).map(...)`.

[thdhhghgbhy]

That's the DOM API, it's not part of the language! They had reasons for querySelectorAll not returning an array.

[eyelidlessness]

> everything gets converted to an array at the drop of a hat

Can you name an example? IME the opposite is a more common complaint: needing to explicitly convert values to arrays from many common APIs which return eg iterables/iterators.

[IshKebab]

`map` returns an array and can only be called on an array.

[eyelidlessness]

Right, but I’m not clear on what gets converted to an array. Do you mean more or less what I said in my previous comment? That it requires you (your code, or calling code in general) to perform that conversion excessively?

[recursive]

People write a lot of stuff like [...iterable].map(fn). They do it so much it's as if they do it each time a hat drops.

[eyelidlessness]

Thank you for clarifying. (I think?)

I think what confused me is the passive language: "everything gets converted" sounds (to me) like the runtime or some aspect of language semantics is converting everything, rather than developers. Whereas this is the same complaint I mentioned.

[Timwi]

One gripe I have is that the result of map/filter is always an array. As a result, doing `foo.map(...).filter(...).slice(0, 3)` will run the map and the filter on the entire array even if it has hundreds of entries and I only need the first 10 to find the 3 that match the filter.