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F# was for me the best functional language when I looked at rewriting a Ruby on Rails app. I wanted to go with a functional language, as it seems to better fit

F# was for me the best functional language when I looked at rewriting a Ruby on Rails app. I wanted to go with a functional language, as it seems to better fit my thinking and reasoning, and I looked at Haskell, Ocaml, Scala, F#. Being a stranger to Microsoft technologies, F# was the least likely to be chosen, but easily became the first choice. Haskell's purity made it hard to adopt (for me), Ocaml's ecosystem is subpar (there wasn't even a clear choice for a library to interact with postgresql, I couldn't install the latest version due to its reliance on an obscure tool whose name I forgot and didn't get help on the forum), and Scala is seems complex.... F# was surprisingly easy to get started with. The community is mis-managed by a corporate-minded approach (requiring people to become member of the F# software foundation to get access to the official slack!), but its members are friendly, smart and ready to help. The ecosystem is great with access to all the dotnet libraries (some complain there's a mismatch as most of those are developed for use with C#, but I rarely got in trouble for using them). There are also great libs and frameworks available. Like https://github.com/SchlenkR/FsHttp https://github.com/SchlenkR/FsHttp to easily interact with http servers, to the point that I find it easier to use than a dedicated library. Or https://github.com/CaptnCodr/Fli https://github.com/CaptnCodr/Fli , to run commands. And last but not least, https://www.websharper.com/ https://www.websharper.com/ is the best web framework I have encountered across all ecosystems. Their reactive approach to web ui really allows me to develop complex interfaces in a maintainable way. This became a longer message than I thought, probably due to my enthousiasm for the language. For complete transparency, the situation is not perfect, and in my experience the tooling is not the best. If you want more info, I blogged about it a couple of months ago: https://www.asfaload.com/blog/consider-fsharp/ https://www.asfaload.com/blog/consider-fsharp/

bozhidar 2y ago
Great story! Thanks for sharing it!
kqr 2y ago
Curious since you don't expand on it on the blog: in what way did Haskell's purity make it difficult to you? Having used Haskell in production for a bit now, I don't even notice its purity. Most functions are in some kind of I/O context making it similar as other languages, except with the option of running without I/O capabilities for functions that shouldn't need it.
- raphinou 2y ago
  I honestly don't remember as it was +/-6 years ago. I had started learning Haskell and got to that conclusion. Maybe that I am now more versed in FP I would arrive at another conclusion? I don't know. Another thing that was hard to grasp for me were the special operators like =<<, ., $, etc. I was using Xmonad, but those operators create a barrier to understanding exactly what happened in the file. In the end, F# was in my (personal) experience much more approachable, and it let me learn the functional concepts along the way.
- giraffe_lady 2y ago
  You gotta remember people are often picking languages based on what they can easily find out about it and extrapolating/guessing about what problems they'll run into with their expected use. A few years ago on here I had an interesting conversation with someone who wasn't going to use rescript for something because they didn't like how it handled object types. I can't remember ever using an object type in rescript; we all just convert js objects to record type in the extern binding. But that's not information easily available to someone who has never used the language. Same thing here I think. If you don't already have familiarity with this paradigm, it's hard to imagine what using an IO monad for side effects is like. It's not easy to tell how hard it'll be to learn it, how much it may affect the rest of your code, etc. It's easy to imagine someone (shit even me a few years ago) going "eh I'll take the language with the big easy escape hatches just in case."
  - fredrikholm 2y ago
    > You gotta remember people are often picking languages based on what they can easily find out about it and extrapolating/guessing about what problems they'll run into with their expected use. This is a good observation. As someone who writes a lot of Lisp, I'm inclined to agree as the amount of people that have never written any Lisp yet immediately reject it over syntax over fears that it somehow hampers development is a (to me) surprisingly large number of people. If I recall correctly, one of the motivating factors for Rescript was to reduce the perceived/real distance between Reason and JS in order to attract more JS devs, as Reason was so heavily associated with OCaml.
- 2y ago
mike1o1 2y ago
There was a large group of folks that left Ruby on Rails for Elixir (even has a similar looking syntax), yet it wasn't on your list of languages to consider. Just curious, was there a particular reason?
- raphinou 2y ago
  I should have mentioned in the message, but I was looking for a strongly typed language. I was an avid-user of dynamically-typed languages, but that particular Ruby on Rails app became unmaintainable, and part of the culprit was due to the dynamic typing. I hoped that using a statically typed language would make it easier to maintain a complex app in the long term. And I must say that it totally materialised, to the point that I don't want to develop in dynamically typed languages anymore. Here's an example: as I said in my original message, I was a complete stranger to the dotnet ecosystem, and I learned the F# language at the same time. And I decided to develop the app as a library project to be used by the web app. I completely missed the prevalence of the async approach in the dotnet, and all my code was synchronous. One day, about half-way in the project, I realised I needed to switch to async code. Had this happened in a dynamically typed project, it would have been hell for me. Maybe it's me that can't grasp a project well enough, but I need the type-guardrails to find my way in large refactorings. And with the strong types, large refactorings can be done confidently. They don't replace tests, but make the refactoring process much more smooth. The app is open source and its code is at: https://gitlab.com/myowndb/myowndb https://gitlab.com/myowndb/myowndb It doesn't have a lot of users, not the least due to lack of marketing and polishing the user experience. But I am satisfied of what I learned developing it!
  - tasuki 2y ago
    These days there's Gleam[0], as a strongly typed alternative for the BEAM virtual machine. Of all the languages I haven't used yet, it seems to hit the safe + minimalistic + productive sweet spot the best. (Yes the C-inspired syntax is slightly off-putting, but syntax is the least important aspect of a language.) [0]: https://gleam.run/ https://gleam.run/
    - 2y ago
breadwinner 2y ago
Apache Spark, Delta Lake are written Scala. Being JVM based, it has a large ecosystem. Scala seems like a better choice than F#.
- raphinou 2y ago
  I'm sure it can be the better choice, but for me it was not. It seems there was some incompatibility between me and Scala. I find it such a complex language and I never managed to wrap my head around it. As I said F# was my last choice at the start of my evaluation, and Scala was high on the list due to the Java ecosystem. But in the end it didn't work out for me. F# on the JVM would be great though!
  - apwell23 2y ago
    i've used scala for over 8 yrs everyday and i agree with your assessment. Even intellij has no idea sometimes about what the hell is going on. It throws up compile errors when there none.
  - flakiness 2y ago
    Is F# easier to learn than Scala? (I know a bit of Scala (in the old 2.x days) but have no knowledge of F#.)
    - raphinou 2y ago
      It definitely was for me! The syntax is simple, it is functional first but is not pure. I started with zero experience with ml languages and got productive fast enough to enjoy it. Of course my early f# code could be improved, but it was working and while writing the code the language didn't feel like a barrier. One caveat though: it seems FP matches my way of thinking. As an example, I always liked recursion, while some others saw it as complexifying things. Try fsharp as fsx scripts to avoid boilerplate (see blog post linked in other comment) and you'll rapidly feel if you like it or not.
    - neonsunset 2y ago
      At least the tooling should be way nicer. It is way more of an OCaml language than Scala. Also much like having to deal with JVM ecosystem in Scala, you'd need to deal with .NET ecosystem in F#. In my opinion, the latter can be an advantage. F# has a lot of depth but you do not need to grasp it fully to be productive with it.
Lanayx 2y ago
For reference, F# slack is already dead, community has moved to Discord https://discord.com/invite/fsharp-196693847965696000 https://discord.com/invite/fsharp-196693847965696000

bozhidar 2y ago

Great story! Thanks for sharing it!

kqr 2y ago

Curious since you don't expand on it on the blog: in what way did Haskell's purity make it difficult to you? Having used Haskell in production for a bit now, I don't even notice its purity. Most functions are in some kind of I/O context making it similar as other languages, except with the option of running without I/O capabilities for functions that shouldn't need it.

raphinou 2y ago
I honestly don't remember as it was +/-6 years ago. I had started learning Haskell and got to that conclusion. Maybe that I am now more versed in FP I would arrive at another conclusion? I don't know. Another thing that was hard to grasp for me were the special operators like =<<, ., $, etc. I was using Xmonad, but those operators create a barrier to understanding exactly what happened in the file. In the end, F# was in my (personal) experience much more approachable, and it let me learn the functional concepts along the way.
giraffe_lady 2y ago
You gotta remember people are often picking languages based on what they can easily find out about it and extrapolating/guessing about what problems they'll run into with their expected use. A few years ago on here I had an interesting conversation with someone who wasn't going to use rescript for something because they didn't like how it handled object types. I can't remember ever using an object type in rescript; we all just convert js objects to record type in the extern binding. But that's not information easily available to someone who has never used the language. Same thing here I think. If you don't already have familiarity with this paradigm, it's hard to imagine what using an IO monad for side effects is like. It's not easy to tell how hard it'll be to learn it, how much it may affect the rest of your code, etc. It's easy to imagine someone (shit even me a few years ago) going "eh I'll take the language with the big easy escape hatches just in case."
- fredrikholm 2y ago
  > You gotta remember people are often picking languages based on what they can easily find out about it and extrapolating/guessing about what problems they'll run into with their expected use. This is a good observation. As someone who writes a lot of Lisp, I'm inclined to agree as the amount of people that have never written any Lisp yet immediately reject it over syntax over fears that it somehow hampers development is a (to me) surprisingly large number of people. If I recall correctly, one of the motivating factors for Rescript was to reduce the perceived/real distance between Reason and JS in order to attract more JS devs, as Reason was so heavily associated with OCaml.
2y ago

mike1o1 2y ago

There was a large group of folks that left Ruby on Rails for Elixir (even has a similar looking syntax), yet it wasn't on your list of languages to consider. Just curious, was there a particular reason?

raphinou 2y ago
I should have mentioned in the message, but I was looking for a strongly typed language. I was an avid-user of dynamically-typed languages, but that particular Ruby on Rails app became unmaintainable, and part of the culprit was due to the dynamic typing. I hoped that using a statically typed language would make it easier to maintain a complex app in the long term. And I must say that it totally materialised, to the point that I don't want to develop in dynamically typed languages anymore. Here's an example: as I said in my original message, I was a complete stranger to the dotnet ecosystem, and I learned the F# language at the same time. And I decided to develop the app as a library project to be used by the web app. I completely missed the prevalence of the async approach in the dotnet, and all my code was synchronous. One day, about half-way in the project, I realised I needed to switch to async code. Had this happened in a dynamically typed project, it would have been hell for me. Maybe it's me that can't grasp a project well enough, but I need the type-guardrails to find my way in large refactorings. And with the strong types, large refactorings can be done confidently. They don't replace tests, but make the refactoring process much more smooth. The app is open source and its code is at: https://gitlab.com/myowndb/myowndb https://gitlab.com/myowndb/myowndb It doesn't have a lot of users, not the least due to lack of marketing and polishing the user experience. But I am satisfied of what I learned developing it!
- tasuki 2y ago
  These days there's Gleam[0], as a strongly typed alternative for the BEAM virtual machine. Of all the languages I haven't used yet, it seems to hit the safe + minimalistic + productive sweet spot the best. (Yes the C-inspired syntax is slightly off-putting, but syntax is the least important aspect of a language.) [0]: https://gleam.run/ https://gleam.run/
  - 2y ago

breadwinner 2y ago

Apache Spark, Delta Lake are written Scala. Being JVM based, it has a large ecosystem. Scala seems like a better choice than F#.

raphinou 2y ago
I'm sure it can be the better choice, but for me it was not. It seems there was some incompatibility between me and Scala. I find it such a complex language and I never managed to wrap my head around it. As I said F# was my last choice at the start of my evaluation, and Scala was high on the list due to the Java ecosystem. But in the end it didn't work out for me. F# on the JVM would be great though!
- apwell23 2y ago
  i've used scala for over 8 yrs everyday and i agree with your assessment. Even intellij has no idea sometimes about what the hell is going on. It throws up compile errors when there none.
- flakiness 2y ago
  Is F# easier to learn than Scala? (I know a bit of Scala (in the old 2.x days) but have no knowledge of F#.)
  - raphinou 2y ago
    It definitely was for me! The syntax is simple, it is functional first but is not pure. I started with zero experience with ml languages and got productive fast enough to enjoy it. Of course my early f# code could be improved, but it was working and while writing the code the language didn't feel like a barrier. One caveat though: it seems FP matches my way of thinking. As an example, I always liked recursion, while some others saw it as complexifying things. Try fsharp as fsx scripts to avoid boilerplate (see blog post linked in other comment) and you'll rapidly feel if you like it or not.
  - neonsunset 2y ago
    At least the tooling should be way nicer. It is way more of an OCaml language than Scala. Also much like having to deal with JVM ecosystem in Scala, you'd need to deal with .NET ecosystem in F#. In my opinion, the latter can be an advantage. F# has a lot of depth but you do not need to grasp it fully to be productive with it.

Lanayx 2y ago

For reference, F# slack is already dead, community has moved to Discord https://discord.com/invite/fsharp-196693847965696000 https://discord.com/invite/fsharp-196693847965696000