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I'm a long-time C# developer, and several years ago tried out F# for a project for which it seemed like a reasonable fit. However, after a month or so, I switch

I'm a long-time C# developer, and several years ago tried out F# for a project for which it seemed like a reasonable fit. However, after a month or so, I switched back to C#. I missed the very strong type inference of F# and pattern matching, and C# suddenly seemed very verbose and awkward to me. But C#'s tooling was just head and shoulders ahead of F#, and that made a huge difference in my productivity. But most of what I was complaining about, it looks like the F# community has addressed. I'll be looking for ways to go back and play with it.

it_learnses 11y ago
I'm also a long time C# developer and I would love to try out F#. what types of projects is F# really good for? Any cool open source projects that you'd recommend?
- JackMorgan 11y ago
  Been using C# for a while now for shrinkwrapped winforms database application and web site. We started intermixing F# in the last year. I've found F# to be better than C# in everything except a few fringe cases where libraries have done things specific to C#. For example, F# has a better ORM framework than anything in C# with Type Providers.... unless you need to support two databases in the same dll. Then when trying to use nHibernate, we found that Nhibernate mappings expect virtual properties, which F# didn't easily do. So we have a C# project with a few C# classes used by the ORM, then a conversion layer into F# domain objects, which we would've done anyway, because ORM classes are terrible at expressing the domain compared to F# records and unions. Other than a few weirdnesses like that, we've found it to be great and otherwise a drop in replacement for C#.
  - bargl 11y ago
    Oh man I don't know where you are working but it sounds like you have some really good leads/architects where you are at. I like my current job, a LOT, but it isn't a development shop and they don't want to use F# because they are trying to limit the languages they support right now (Too many legacy apps). Which I understand, but at the same time I think we are really missing out. Especially because they are developing the front end to be a very Functional Typescrip SPA. Anyway I've been learning F# in my spare time just for the heck of it.
  - it_learnses 11y ago
    Thanks for this :) A slightly tangential question: at what point does using ORM become painful? When would you recommend going back to sprocs?
    - JackMorgan 11y ago
      Like when does it make sense to have a business representation of your data in a language like F#? I'd say as soon as you want the full expressive power and safety of records and discriminated unions. Our domain representation was substantially different from what would easily fit in a relational database, so we start with it from the beginning. In C#, I think ORM classes have a lot going on, so I prefer to use them only for converting to a data structure.
- chadzawistowski 11y ago
  I find F# to be really great for scripty things. Honestly, it's more of a Python replacement than C# for me. I've scripted Google Maps scraping using F#. It doesn't showcase any particularly functional features, but you can see there is very little code (relative to C#) in order to accomplish what I needed. [0] P/Invoke works well, too. I've called native Windows APIs to audit user-mode and kernel-mode memory usage. [1] The last project generates a Mandelbrot image in parallel. It's as easy as `Array.Parallel.init` on line #81! [2] [0] https://github.com/ChadSki/MapMaker/blob/master/MapMaker/Program.fs https://github.com/ChadSki/MapMaker/blob/master/MapMaker/Pro... [1] https://github.com/ChadSki/RamCensus/blob/master/RamCensusFs/Program.fs https://github.com/ChadSki/RamCensus/blob/master/RamCensusFs... [2] https://github.com/ChadSki/FSharpMandelbrot/blob/master/FSharpMandelbrot/Program.fs#L81 https://github.com/ChadSki/FSharpMandelbrot/blob/master/FSha...
- edgyswingset 11y ago
  A web API is a great candidate. Or really, anything that needs to work well at scale.
  - ZenoArrow 11y ago
    I agree a web API is a good project to start with. If anyone is thinking about trying this out, it's worth checking out Suave (worth noting that it's cross platform, works on Mac and Linux too): http://blog.tamizhvendan.in/blog/2015/07/23/creating-mock-api-server-in-fsharp-using-suave/ http://blog.tamizhvendan.in/blog/2015/07/23/creating-mock-ap...
- tpetricek 11y ago
  This blog post might give you some good ideas: http://fsharpforfunandprofit.com/posts/low-risk-ways-to-use-fsharp-at-work/ http://fsharpforfunandprofit.com/posts/low-risk-ways-to-use-... That said, people have used F# for pretty much everything - including data science and analytics, domain modelling (and business application development), testing (Canopy for web testing), build automation (check out FAKE and Paket). I guess you get the most value from F# by using it for some analytical component (implementing some logic), but the above blog post has many great ideas in other areas too.
- Scuds 11y ago
  One thing though, you'll want to _really_ learn the type system and lean heavily upon it so that the compiler can guide you to build up your system. It's the old adage of "Show me your [code] and conceal your [data structures], and I shall continue to be mystified. Show me your [data structures], and I won't usually need your [code]; it'll be obvious." -- Fred Brooks I'm digging this poker hands Kata http://codereview.stackexchange.com/questions/43831/poker-hands-kata-in-f http://codereview.stackexchange.com/questions/43831/poker-ha...
- MichaelGG 11y ago
  F# exceeds C#'s capabilities in essentially every way. The only time C# does much better is when you need the VS drag n drop GUI tools. Some folks also feel more comfortable doing certain types of very imperative code in C#. Other than that, sometimes there are problems with libraries that specifically target the C# compiler's exact output. Examples are functions that take an object, then dynamically look at the property names instead of just using a dictionary (F# can do this, just isn't a major focus like in C#). Or poorly written expression tree code that only works with C#'s output. That said, the F# community can often find a fix. Once you adjust to writing so much less code, it's very hard to enjoy writing C#.
mamcx 11y ago
I drop the .NET ecosystem long time ago. F# make me look at it, and mostly, the opportunity to use it on OSX/Linux/iOS. I'm uninterested in C#; so I'm trying to make the case for F# (and to be more brutal: And work good enough under OSX, because all my dev work is on it; plus looking to do iOS dev with F#: That is harder than I was expecting!). I like the language, not as much as python/pascal but is great enough. I'm toying to build a compiler, and building some utils and porting (ie: experimenting ;) ) a massive obj-c project. So far, my only gripe, is the extremely weak support for any other database that is not Sql Server. No F# native ORM work on OSX as-is. Sql Type-providers neither. You can make some basic stuff and crash faster after you try anything barely complex, like do a search ;) I was forced to use NServiceKit (a clone of ServiceKit before go commercial) because was the one that I made to work, but then is made in C# and it break the expectations I was having with F# (like https://stackoverflow.com/questions/31866227/why-im-getting-null-for-a-string-in-f/31885583#31885583 https://stackoverflow.com/questions/31866227/why-im-getting-...) So, that is my 5-cents: Expect pain outside VS/Sql Server, and I'm not fully convinced on the Web story neither (ie: Nothing as great + simple as django or flask on python)
- yareally 11y ago
  > No F# native ORM work on OSX as-is. Sql Type-providers neither. You can make some basic stuff and crash faster after you try anything barely complex, like do a search ;) There exists a very good ADO.net wrapper for F# called FsSQL https://github.com/mausch/FsSql https://github.com/mausch/FsSql Dapper can also be used with F#: https://gist.github.com/vbfox/1e9f42f6dcdd9efd6660 https://gist.github.com/vbfox/1e9f42f6dcdd9efd6660 Neither are true ORM compared to say nHibernate, but both include mapping to .net collections. I generally prefer this approach over a true ORM for flexibility.

it_learnses 11y ago

I'm also a long time C# developer and I would love to try out F#. what types of projects is F# really good for? Any cool open source projects that you'd recommend?

JackMorgan 11y ago
Been using C# for a while now for shrinkwrapped winforms database application and web site. We started intermixing F# in the last year. I've found F# to be better than C# in everything except a few fringe cases where libraries have done things specific to C#. For example, F# has a better ORM framework than anything in C# with Type Providers.... unless you need to support two databases in the same dll. Then when trying to use nHibernate, we found that Nhibernate mappings expect virtual properties, which F# didn't easily do. So we have a C# project with a few C# classes used by the ORM, then a conversion layer into F# domain objects, which we would've done anyway, because ORM classes are terrible at expressing the domain compared to F# records and unions. Other than a few weirdnesses like that, we've found it to be great and otherwise a drop in replacement for C#.
- bargl 11y ago
  Oh man I don't know where you are working but it sounds like you have some really good leads/architects where you are at. I like my current job, a LOT, but it isn't a development shop and they don't want to use F# because they are trying to limit the languages they support right now (Too many legacy apps). Which I understand, but at the same time I think we are really missing out. Especially because they are developing the front end to be a very Functional Typescrip SPA. Anyway I've been learning F# in my spare time just for the heck of it.
- it_learnses 11y ago
  Thanks for this :) A slightly tangential question: at what point does using ORM become painful? When would you recommend going back to sprocs?
  - JackMorgan 11y ago
    Like when does it make sense to have a business representation of your data in a language like F#? I'd say as soon as you want the full expressive power and safety of records and discriminated unions. Our domain representation was substantially different from what would easily fit in a relational database, so we start with it from the beginning. In C#, I think ORM classes have a lot going on, so I prefer to use them only for converting to a data structure.
chadzawistowski 11y ago
I find F# to be really great for scripty things. Honestly, it's more of a Python replacement than C# for me. I've scripted Google Maps scraping using F#. It doesn't showcase any particularly functional features, but you can see there is very little code (relative to C#) in order to accomplish what I needed. [0] P/Invoke works well, too. I've called native Windows APIs to audit user-mode and kernel-mode memory usage. [1] The last project generates a Mandelbrot image in parallel. It's as easy as `Array.Parallel.init` on line #81! [2] [0] https://github.com/ChadSki/MapMaker/blob/master/MapMaker/Program.fs https://github.com/ChadSki/MapMaker/blob/master/MapMaker/Pro... [1] https://github.com/ChadSki/RamCensus/blob/master/RamCensusFs/Program.fs https://github.com/ChadSki/RamCensus/blob/master/RamCensusFs... [2] https://github.com/ChadSki/FSharpMandelbrot/blob/master/FSharpMandelbrot/Program.fs#L81 https://github.com/ChadSki/FSharpMandelbrot/blob/master/FSha...
edgyswingset 11y ago
A web API is a great candidate. Or really, anything that needs to work well at scale.
- ZenoArrow 11y ago
  I agree a web API is a good project to start with. If anyone is thinking about trying this out, it's worth checking out Suave (worth noting that it's cross platform, works on Mac and Linux too): http://blog.tamizhvendan.in/blog/2015/07/23/creating-mock-api-server-in-fsharp-using-suave/ http://blog.tamizhvendan.in/blog/2015/07/23/creating-mock-ap...
tpetricek 11y ago
This blog post might give you some good ideas: http://fsharpforfunandprofit.com/posts/low-risk-ways-to-use-fsharp-at-work/ http://fsharpforfunandprofit.com/posts/low-risk-ways-to-use-... That said, people have used F# for pretty much everything - including data science and analytics, domain modelling (and business application development), testing (Canopy for web testing), build automation (check out FAKE and Paket). I guess you get the most value from F# by using it for some analytical component (implementing some logic), but the above blog post has many great ideas in other areas too.
Scuds 11y ago
One thing though, you'll want to _really_ learn the type system and lean heavily upon it so that the compiler can guide you to build up your system. It's the old adage of "Show me your [code] and conceal your [data structures], and I shall continue to be mystified. Show me your [data structures], and I won't usually need your [code]; it'll be obvious." -- Fred Brooks I'm digging this poker hands Kata http://codereview.stackexchange.com/questions/43831/poker-hands-kata-in-f http://codereview.stackexchange.com/questions/43831/poker-ha...
MichaelGG 11y ago
F# exceeds C#'s capabilities in essentially every way. The only time C# does much better is when you need the VS drag n drop GUI tools. Some folks also feel more comfortable doing certain types of very imperative code in C#. Other than that, sometimes there are problems with libraries that specifically target the C# compiler's exact output. Examples are functions that take an object, then dynamically look at the property names instead of just using a dictionary (F# can do this, just isn't a major focus like in C#). Or poorly written expression tree code that only works with C#'s output. That said, the F# community can often find a fix. Once you adjust to writing so much less code, it's very hard to enjoy writing C#.

mamcx 11y ago

I drop the .NET ecosystem long time ago. F# make me look at it, and mostly, the opportunity to use it on OSX/Linux/iOS. I'm uninterested in C#; so I'm trying to make the case for F# (and to be more brutal: And work good enough under OSX, because all my dev work is on it; plus looking to do iOS dev with F#: That is harder than I was expecting!). I like the language, not as much as python/pascal but is great enough. I'm toying to build a compiler, and building some utils and porting (ie: experimenting ;) ) a massive obj-c project. So far, my only gripe, is the extremely weak support for any other database that is not Sql Server. No F# native ORM work on OSX as-is. Sql Type-providers neither. You can make some basic stuff and crash faster after you try anything barely complex, like do a search ;) I was forced to use NServiceKit (a clone of ServiceKit before go commercial) because was the one that I made to work, but then is made in C# and it break the expectations I was having with F# (like https://stackoverflow.com/questions/31866227/why-im-getting-null-for-a-string-in-f/31885583#31885583 https://stackoverflow.com/questions/31866227/why-im-getting-...) So, that is my 5-cents: Expect pain outside VS/Sql Server, and I'm not fully convinced on the Web story neither (ie: Nothing as great + simple as django or flask on python)

yareally 11y ago
> No F# native ORM work on OSX as-is. Sql Type-providers neither. You can make some basic stuff and crash faster after you try anything barely complex, like do a search ;) There exists a very good ADO.net wrapper for F# called FsSQL https://github.com/mausch/FsSql https://github.com/mausch/FsSql Dapper can also be used with F#: https://gist.github.com/vbfox/1e9f42f6dcdd9efd6660 https://gist.github.com/vbfox/1e9f42f6dcdd9efd6660 Neither are true ORM compared to say nHibernate, but both include mapping to .net collections. I generally prefer this approach over a true ORM for flexibility.