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Currying is nice but in practice it’s rather esoteric in the JavaScript ecosystem. I’ve only seen currying being used (if at all) when transforming data with ut

Currying is nice but in practice it’s rather esoteric in the JavaScript ecosystem. I’ve only seen currying being used (if at all) when transforming data with utility libraries like ramda[1]. What makes it worse it that partial application is rather cumbersome to type. Lucky for us there is a partial application proposal, albeit still in stage 1, which makes partial application—to make functions curried—a lot easier[2]. [1] https://ramdajs.com/docs/#curry https://ramdajs.com/docs/#curry [2] https://github.com/tc39/proposal-partial-application https://github.com/tc39/proposal-partial-application

renke1 5y ago
The partial application proposal looks reasonable and intuitive. Definitely something I would use. Is there any prior art (other languages etc.)? Mh, it's already 4 years old. What a shame.
- weego 5y ago
  Scala has partially applied functions that use a very similar idiom
- alexfoxgill 5y ago
  It is used heavily in Scala https://alvinalexander.com/scala/how-to-use-partially-applied-functions-in-scala-syntax-examples/ https://alvinalexander.com/scala/how-to-use-partially-applie...
  - masklinn 5y ago
    Clojure has the "thread-as" macro (`as->`), but I don't think it's used much: usually thread-first (`->`) and thread-last (`->>`) will more than do the job and have less mental overhead due to their regularity.
- graftak 5y ago
  There’s a lot of bikeschedding on how to use it in conjunction with the (also stage 1 proposal and forever delayed) pipeline operator[1] unfortunately. Add in never ending arguments on which symbol we should use (the questionmark has a lot of responsibilities already) and here we are. To make matters worse it appear that generally OOP style darlings such as static class blocks and true private fields seem to gain more momentum. [1] https://github.com/tc39/proposal-pipeline-operator/wiki https://github.com/tc39/proposal-pipeline-operator/wiki
eurasiantiger 5y ago
Note that currying, especially with Ramda, has a very large negative performance impact. ” To improve the compositionality of our code we had defined a ton of curried functions using Ramda. But every abstraction has a cost associated with it. On profiling, we found out that the `curry` function was taking up a lot of CPU. Benchmarks show that removing curry from the code makes it up to 100 times faster. Curry function is at the core of Ramda, almost every function is curried.” https://blog.dream11engineering.com/lessons-learned-from-running-graphql-at-scale-2ad60b3cefeb https://blog.dream11engineering.com/lessons-learned-from-run...
- IceDane 5y ago
  Wow, that is pretty awful. I'm a pretty big fan of strong, static type systems and FP in general, and I have been writing typescript professionally for a few years now. I decided a long time ago that trying to write Haskell in TS just isn't worth the effort. Adopting FP ideas such as pure functions, restricting side-effects and then otherwise just using the type system to model the flow of your program goes a very long way. You don't have to write Haskell in TS to reap most of the benefits.
  - toastal 5y ago
    You can also just not use TypeScript if you want something more appropriate for functional programming styles. I know it's not always practical to switch languages, but it's equally impractical to push unergonomic, unidiomatic styles on language not built for it. There are a lot of good options to compile an FP language to JavaScript, and frankly those languages deserve more mindshare than pressing so hard on fp-ts.
    - khalilravanna 5y ago
      What’s unergonomic or unidiomatic about TS? As far as I understand it TS is supposed to follow as closely to JS as possible. I always saw it as “let’s add types to JS” rather than a separate language. I’m not sure I’ve seen a “this is how you write TS vs JS” formal declaration from the TS team. Am I missing something?
runarberg 5y ago
I have strong doubts that partial application will ever advance from stage 1. The reason is that partial application was supposed to compliment the pipeline operator[1]. value |> fn(?, "static string") However earlier this month they advanced a version of the pipeline operator with a definite topic marker which makes partial application useless in the RHS of the pipeline operator. This was of course really controversial, as you can see if you read thought the most resent issues (particularly the closed ones). https://github.com/tc39/proposal-pipeline-operator https://github.com/tc39/proposal-pipeline-operator

renke1 5y ago

The partial application proposal looks reasonable and intuitive. Definitely something I would use. Is there any prior art (other languages etc.)? Mh, it's already 4 years old. What a shame.

weego 5y ago
Scala has partially applied functions that use a very similar idiom
alexfoxgill 5y ago
It is used heavily in Scala https://alvinalexander.com/scala/how-to-use-partially-applied-functions-in-scala-syntax-examples/ https://alvinalexander.com/scala/how-to-use-partially-applie...
- masklinn 5y ago
  Clojure has the "thread-as" macro (`as->`), but I don't think it's used much: usually thread-first (`->`) and thread-last (`->>`) will more than do the job and have less mental overhead due to their regularity.
graftak 5y ago
There’s a lot of bikeschedding on how to use it in conjunction with the (also stage 1 proposal and forever delayed) pipeline operator[1] unfortunately. Add in never ending arguments on which symbol we should use (the questionmark has a lot of responsibilities already) and here we are. To make matters worse it appear that generally OOP style darlings such as static class blocks and true private fields seem to gain more momentum. [1] https://github.com/tc39/proposal-pipeline-operator/wiki https://github.com/tc39/proposal-pipeline-operator/wiki

eurasiantiger 5y ago

Note that currying, especially with Ramda, has a very large negative performance impact. ” To improve the compositionality of our code we had defined a ton of curried functions using Ramda. But every abstraction has a cost associated with it. On profiling, we found out that the `curry` function was taking up a lot of CPU. Benchmarks show that removing curry from the code makes it up to 100 times faster. Curry function is at the core of Ramda, almost every function is curried.” https://blog.dream11engineering.com/lessons-learned-from-running-graphql-at-scale-2ad60b3cefeb https://blog.dream11engineering.com/lessons-learned-from-run...

IceDane 5y ago
Wow, that is pretty awful. I'm a pretty big fan of strong, static type systems and FP in general, and I have been writing typescript professionally for a few years now. I decided a long time ago that trying to write Haskell in TS just isn't worth the effort. Adopting FP ideas such as pure functions, restricting side-effects and then otherwise just using the type system to model the flow of your program goes a very long way. You don't have to write Haskell in TS to reap most of the benefits.
- toastal 5y ago
  You can also just not use TypeScript if you want something more appropriate for functional programming styles. I know it's not always practical to switch languages, but it's equally impractical to push unergonomic, unidiomatic styles on language not built for it. There are a lot of good options to compile an FP language to JavaScript, and frankly those languages deserve more mindshare than pressing so hard on fp-ts.
  - khalilravanna 5y ago
    What’s unergonomic or unidiomatic about TS? As far as I understand it TS is supposed to follow as closely to JS as possible. I always saw it as “let’s add types to JS” rather than a separate language. I’m not sure I’ve seen a “this is how you write TS vs JS” formal declaration from the TS team. Am I missing something?

runarberg 5y ago

I have strong doubts that partial application will ever advance from stage 1. The reason is that partial application was supposed to compliment the pipeline operator[1]. value |> fn(?, "static string") However earlier this month they advanced a version of the pipeline operator with a definite topic marker which makes partial application useless in the RHS of the pipeline operator. This was of course really controversial, as you can see if you read thought the most resent issues (particularly the closed ones). https://github.com/tc39/proposal-pipeline-operator https://github.com/tc39/proposal-pipeline-operator