Fable4

[wallymathieu]

• Adjust code in order for Fable4 compilation to work
• Add CI to test Fable3 and Fable4 compilation

[wallymathieu]

Based on comment :
#537 (comment)
Let us try out to see what happens when you compile with Fable4

[wallymathieu]

After adding checks for Fable4 I'm getting:

./../../src/FSharpPlus/Control/Functor.fs(1,1): error FABLE: Cannot have two module members with same name: Map_Map_257C72F5
./../../src/FSharpPlus/Control/Functor.fs(1,1): error FABLE: Cannot have two module members with same name: Unzip_Unzip_Z1EFE1B1E
./../../src/FSharpPlus/Control/Functor.fs(1,1): error FABLE: Cannot have two module members with same name: Zip_Zip_7A9EA139
./../../src/FSharpPlus/Control/Functor.fs(1,1): error FABLE: Cannot have two module members with same name: Dimap_Dimap_5ECA39C1
./../../src/FSharpPlus/Control/Functor.fs(1,1): error FABLE: Cannot have two module members with same name: Contramap_Contramap_Z16BE31C1
./../../src/FSharpPlus/Control/Invokable.fs(1,1): error FABLE: Cannot have two module members with same name: Invoke_Invoke_56C4DC00
./../../src/FSharpPlus/Control/Category.fs(1,1): error FABLE: Cannot have two module members with same name: Id_Id_6D84815D
./../../src/FSharpPlus/Control/Category.fs(1,1): error FABLE: Cannot have two module members with same name: Comp_$003C$003C$003C_Z7E4A116E
./../../src/FSharpPlus/Control/Arrow.fs(1,1): error FABLE: Cannot have two module members with same name: Arr_Arr_Z242EF1B9
./../../src/FSharpPlus/Control/Arrow.fs(1,1): error FABLE: Cannot have two module members with same name: ArrFirst_First_7EEFD19D
./../../src/FSharpPlus/Control/Arrow.fs(1,1): error FABLE: Cannot have two module members with same name: ArrSecond_Second_A1C8017
./../../src/FSharpPlus/Control/Arrow.fs(1,1): error FABLE: Cannot have two module members with same name: ArrCombine_$002A$002A$002A_Z5FDD3AD0
./../../src/FSharpPlus/Control/Arrow.fs(1,1): error FABLE: Cannot have two module members with same name: Fanout_$0026$0026$0026_Z5CA5C083
./../../src/FSharpPlus/Control/ArrowApply.fs(1,1): error FABLE: Cannot have two module members with same name: App_App_257C63C8
./../../src/FSharpPlus/Control/ArrowChoice.fs(1,1): error FABLE: Cannot have two module members with same name: Fanin_$007C$007C$007C_Z22DED874
./../../src/FSharpPlus/Control/ArrowChoice.fs(1,1): error FABLE: Cannot have two module members with same name: AcMerge_$002B$002B$002B_Z75846F16
./../../src/FSharpPlus/Control/Monad.fs(129,52): (129,130) error FABLE: Cannot resolve trait call Return - Inline call from .(142,83) < ../../../tests/FSharpPlusFable.Tests/FSharpTests/General/Monad.fs(29,12)

The interesting part seem to be Cannot have two module members with same name

[reinux]

Hey, don't mean to nag, but do you think you'll be able to get around to this anytime soon?

If not it's totally cool, I can put off the UI portions of my project for now or just skip FSharpPlus on the frontend.

[lukaszkrzywizna]

I can put off the UI portions of my project for now or just skip FSharpPlus on the frontend.

I have the same problem. Maybe we can help somehow? It would be very helpful if we know if there are any plans to support this in the near future (or not) :)

[wallymathieu]

Unless something changes with Fable 4, the solution requires the if def removal of quite a lot of overloaded class methods. Perhaps we can sync with Fable team.

[wallymathieu]

Perhaps the goal of Fable4 is to improve compiler performance but pulling back on some F# language features. Since frontend developers expect different compiler performance than many backend programmers, that might make a lot of sense.

[wallymathieu]

Hey, don't mean to nag, but do you think you'll be able to get around to this anytime soon?

If not it's totally cool, I can put off the UI portions of my project for now or just skip FSharpPlus on the frontend.

Main reason why this PR has been left dangling has been that I've been quite busy with lots of work thus have not had time to spend any so much time on open source (not directly related to project/contract/whatnot).

[reinux]

All good, thanks!

[lukaszkrzywizna]

Thank you so much! This lib is a great piece of code and helps me (and my team) a lot! One more time thank you! :)

[lukaszkrzywizna]

Last question: when do you plan to release a new version?

[wallymathieu]

I've uploaded a pre-release package on NuGet, please have a look if it works ok
https://www.nuget.org/packages/FSharpPlus/1.4.1-v1.4-CI03263

[lukaszkrzywizna]

Unfortunately, there is still an error:

client: .\src\SaferLab.Client\Pages\Index.fs(32,21): (32,24) error FSHARP: Expecting a type supporting the operator '|>>' but given a function type. You may be missing an argument to a function. (code 43)

[wallymathieu]

The best thing would be to submit a lot of the use cases you have as tests and see if we can get it to work. Some of the issues are due to the fact that Fable 4 does not support the same overloading as seen in Fable 3.

[wallymathieu]

That operator is not available in Fable 4 version of F#+ due to limitations in Fable. In order to implement the operators you would probably need to use other mechanisms to implement those features (JavaScript runtime polymorpism).

[wallymathieu]

Though, some features might not be possible due to the absence of type information in the runtime.