Zeljko Nesic (Apr 24 2021 at 21:50): Zeljko Nesic (Apr 24 2021 at 21:50):I am trying to understand what is this doing:
app "main" imports [ Effect ] provides [ rocMain ] to "./platform"
I mean this provides ... to ..... syntax, not sure what changes in platfrom
Folkert de Vries (Apr 24 2021 at 21:51):the compiler needs to know what the main function is, and what the platform is that you want to compile
Zeljko Nesic (Apr 24 2021 at 21:52):Ah, so no main as default?
Chad Stearns (Apr 24 2021 at 21:53):Oh interesting, and its a list? So could it be [ mainA, mainB ]?
Folkert de Vries (Apr 24 2021 at 21:53):right. This might be something to reconsider now. Originally, the idea was that you could hand multiple things to the platform (e.g. provide a update, a view, ect as separate functions)
Folkert de Vries (Apr 24 2021 at 21:54):but we've confirmed that bundling all those functions in a record has no overhead; LLVM completely optimizes the struct/record away
Zeljko Nesic (Apr 24 2021 at 21:54):❯ cat examples/balance/Main.roc
app "main" imports [ Effect ] provides [ rocMain, roKMain ] to "./platform"
rocMain : Effect.Effect {} as Fx
rocMain = ..
roKMain : Effect.Effect {} as Fx
roKMain = ..
THis is invalid syntax right?
There can be only one?!
:D
Folkert de Vries (Apr 24 2021 at 21:55):well no, a platform could decide to allow this
Folkert de Vries (Apr 24 2021 at 21:55):e.g. provides [ serverMain, clientMain ]
Chad Stearns (Apr 24 2021 at 21:55):So, in theory, there could be a Roc mono repo, with the frontend and backend code base, like:
provides [ view, update, dbConnection, http ]
?
Zeljko Nesic (Apr 24 2021 at 21:55):that should be a record then?
Folkert de Vries (Apr 24 2021 at 21:56):yea I think that is generally preferable
Folkert de Vries (Apr 24 2021 at 21:56):because then you have better docs for what the platform needs
Zeljko Nesic (Apr 24 2021 at 21:56):provides { view, update: mainUpdateFix2 } to "xy"
Zeljko Nesic (Apr 24 2021 at 21:58):but that is would be then equal to defaulting to only one main, where platform provides a spec what kind of data type it should be?
Last updated: Jul 26 2025 at 12:14 UTC