F# or C# for personal Silverlight project?

Question

Hi all,

I'm about to start working on a rich-internet-application project for a student organization at my university. I will be the only programmer, and what technologies to use is totally up to me. I've already decided on going with Silverlight, but I'm not sure whether to use C# or F#. Here are some of the things I'm keeping in mind:

C#:

• I already know it and have used it extensively with Silverlight at work. I have no F# and little general FP experience.
• Some say the OOP paradigm works better for complex stateful UIs.
• Maintenance: I'll be in school for three more years, but after that if the app is still in use they may have a better time finding someone else to maintain it if I use a more common language.
• C# experience is probably more valuable in the "real world".

F#:

• The main reason is I want to learn something new. Functional programming languages seem pretty cool (I find myself using the FP features of C# very often, and think they're the biggest improvement in C# 3.0). I think I'd have a lot more fun if I used F#, but am I being unrealistic in thinking the cost in time and effort might not outweigh the benefits?

Answer 1

I know it's not in your list, but if you're interested in learning something new, you might consider GWT - You write your client in Java (which ought to be an easy jump from C#), and then the compiler turns the client side into JavaScript. Should be a bit more cross-platform compatible than Silverlight, and it's an interesting fusion of technologies (CSS, JavaScript, and Java aren't going anywhere in the near future).

Answer 2

In my opinion, when you are a student, you should be trying to put your fingers in as many pots as possible.

The more languages you play with, the more understanding you will have of the "best" ways of doing things in a specific language.

As for "experience" being more valuable in the "real world". Personally I only ever consider true commercial experience when looking at potential candidates. Experience in a language when you're in a job and being paid is extremely different to experience in using a language when learning / studying it. Things you do whilst studying are about gaining skills and knowledge whereas things you do in a commercial environment give you experience in solving real life problems.

Bottom line... play with the cool stuff whilst you still can!

Answer 3

Because you expect to create something useful that will live past your tenure as maintainer, I would suggest writing the majority in C#. What you can do to scratch your new-technology-itch, though, is pull out distinct, well-defined components that don't interact directly with the UI and write those in a separate F# assembly.

I've done something similar with a project that I've open sourced in the past. My fundamental UI logic (in this case, the V-VM parts of the M-V-VM) were in C# because it works so well with WPF technologies. Then, certain functionally-oriented components of the Model itself I broke out into a separate assembly and wrote in F# just to get some limited exposure to the language.

It's not a jump-with-both-feet approach to learning technology, so I probably didn't learn as much as I could have. An F#-only project wouldn't have taught me nearly as much about exposing F# functionality to the greater .Net world in a friendly way, either, though.

No matter what, the key in a situation like this is for you to have fun and enjoy what you're doing. :)

Answer 4

You can make F# business logics project (a dll).

And then the user interface in C#. And in user interface project you can add a reference to the F#-library.

This is a good solution in general when using Silverlight: The power of F# is (functional) programming but currently C# will have a better tool-support.

Answer 5

I just gave a talk about programming reactive Silverlight applications in F# at London F# user-group meeting. The recording of the talk (and samples) are available here, so you can take a look at that.

Here are a few points you could consider:

• I think F# has some very nice features that make programming this kind of applications more elegant than in C# (for example, you can nicely model program as a state machine and encode this direcly in code).

• F# is still relatively new, but I believe that there is a decent chance that finding someone familiar with F# after three years will be much easier than today (and finding younger students who are interested to learn something new should be easier :-)).

• I was surprised that there is already quite a demand for good F# programmers in the London area. This will be probably different in different places, but I think that F# is becoming a "nice-to-have" feature on CV for some jobs.

Answer 6

I'm presuming that this will be used in an intranet environment. Otherwise, I'd question whether the choice of Silverlight is really the best due to market penetration. The second point I'd raise is that one of the really key skills for most web developers is Javascript. (Nowadays, that would be Javascript with a library like JQuery to manipulate the DOM, simplify AJAX, etc.) unless the application is particularly complex, there might be some merit in considering DHTML+Javascript as a starting point, and only looking at other technologies if it proves too much for that. However, if you're set on going down the Silverlight route, then C# is by far the most likely to be supported. If you're still learning, then it's also the route that has the best documentation. F# has some excellent documentation around, but unfortunately not nearly as much as for C#. You briefly mention the time and cost commitment. Unless you're quite comfortable with functional programming, F# is liable to take significantly longer, in part due to unfamiliarity and in part due to the amount of reference documentation to help you on your way. While it it undoubtedly good to have knowledge of a range of programming languages under your belt, what's more valuable to most employers is a solid understanding of their language of choice - so diversifying too much can miss that. When looking to learn an unfamiliar programming language starting with something like solving Project Euler problems may present a better way of starting out, rather than diving straight into a major project with a new language. If you start in C#, you can always create an F# project that implements functions more suitable for its focus, and reference it from the C# one, to dip your toe in its waters while not automatically committing a lot of additional time to it.