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Comment by pjc50

3 days ago

The funny thing is that you can write very similar code in C#, so maybe you don't need to switch which language you're using as a CLR frontend.

    using System.Linq;
    using System;

    var names = new string[] {"Peter", "Julia", "Xi" };
    names.Select(name => $"Hello, {name}").ToList().ForEach(greeting =>   Console.WriteLine($"{greeting}! Enjoy your C#"));

LINQ is such a good library that I miss it in other languages. The Java stream equivalent just doesn't feel as fluent.

36 comments

pjc50

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psychoslave  2 days ago

As far as fluency goes, that’s not very impressive.

    %w{Peter Julia Xi}.map{"Hello, #{it}"}.each{puts "#{it}! Enjoy your Ruby"}

That’s of course trivial examples. And while Ruby now have RBS and Sorbet, it’s yet another tradeoff compared to a syntax that has upfront static analysis as first class citizen in mind.

That is, each language will have its strong and weak points, but so far on "fluency" I’m not aware of anything that really beat Ruby far beyond as Ruby does compared to other mainstream programming languages.

  • int_19h  2 days ago

    Ruby is dynamically typed, which makes "fluent" API design that much easier at the cost of maintainability elsewhere. If you want to compare apples to apples, you need to compare F# to other statically typed languages.

    • psychoslave  2 days ago

      Also note that the following is a valid Crystal-lang code:

         %w[Peter Julia Xi].map { |name| "Hello, #{name}" }.each { |greeting| puts "#{greeting}! Enjoy your Crystal" }

      As they put it:

      >Crystal is a general-purpose, object-oriented programming language. With syntax inspired by Ruby, it's a compiled language with static type-checking.

      But this time, one can probably say that Crystal will lake the benefits of ecosystem that only a large popular language enjoy.

      I guess on that side F#, relying on .Net, is closer to Kotlin with Java ecosystem.

      2 replies →

issafram  2 days ago

You're being way too nice. Java stream is nowhere near as easy to use as LINQ. I'd say that LINQ is easily one of the top 10 coding features that Microsoft has ever created.

  • DeathArrow  2 days ago

    I think LINQ is inspired by SQL. You can do whatever you can with SQL, it's just that the data source might differ IEnumerable with some in memory data, IQueryable with some DB. Or you can use async enumerable and your data source can be whatever web API or protocol.

bob1029  3 days ago

You can write a vast majority of your C# codebase in a functional style if you prefer to.

All the good stuff has been pirated from F# land by now: First-class functions, pattern matching, expression-bodied members, async functional composition, records, immutable collections, optional types, etc.

  • int_19h  2 days ago

    I wouldn't say "all" - C# doesn't have discriminated unions yet, which is kind of a big one, especially when you're also looking at pattern matching. A

  • UK-Al05  3 days ago

    A language is just as much about what it can't do, then what it can do.

    • bob1029  2 days ago

      Can you elaborate on what you mean by this?

      I assume you are implying that too many choices could confuse a junior developer, which I agree with. However, I don't think this is a concern in the bigger picture when talking about the space of all languages.

      2 replies →

  • guhidalg  3 days ago

    I don't know if there's a name for it but essentially F# is where the language designers can push the boundaries and try extremely new things that 99% of users will not want or need, but eventually some of them are such good ideas that they feed back into C#.

    Maybe that's just research, and I'm glad that Microsoft hasn't killed F# (I do work there, but I don't write F# at work.)

    • debugnik  2 days ago

      > F# is where the language designers can push the boundaries

      It really isn't, not anymore. F# now evolves conservatively, just trying to remove warts and keep up with C# interop.

      And even then some C# features were considered too complex/powerful to implement (e.g. variance, scoped refs) or implemented in weaker, incompatible ways when C#'s design is considered messy (e.g. F#'s non-nullable constraints disallow value-types, which breaks for some generic methods written in C#, sadly even part of the System libs).

klysm  3 days ago

This isn’t a great example of what linq is good at. There’s no reason to do ToList there, and the ForEach isn’t particularly idiomatic

  • pjc50  3 days ago

    Yeah, I hit the problem that there isn't a null-type equivalent of Select() for Action<T>, nor is there a IEnumerable.ForEach (controversial), so that's a bit of a hack. But I wanted to make it as close to the original example as possible.

  • bob1029  2 days ago

    > There’s no reason to do ToList there

    In this case, I would move it to the very end if we are concerned about the underlying data shifting when the collection is actually enumerated.

    Forgetting to materialize LINQ results can cause a lot of trouble, oftentimes in ways that happily evade detection while a debugger is attached.

    • klysm  2 days ago

      > if we are concerned about the underlying data shifting when the collection is actually enumerated

      I’m not sure what you mean by this. You can fulfill the IEnumerable contract without allowing multiple enumerations, but that doesn’t really have to do with the data shifting around. Doing ToList can be an expensive and unnecessary allocation

      2 replies →

kkukshtel  3 days ago

Modern C# collection expressions make the definition of names closer to F#:

  string[] names = ["Peter", "Julia", "Xi"];

I know working on "natural type" of collections is something the C# team is working on, so it feels possible in the future that you'll be able to do this:

  var names = ["Peter", "Julia", "Xi"];

Which I think would then allow:

  ["Peter", "Julia", "Xi"].Select(name => $"Hello, {name}").ToList().ForEach(greeting =>   Console.WriteLine($"{greeting}! Enjoy your C#"));

  • pjc50  3 days ago

    I did try that initially and got

        <source>(5,1): error CS9176: There is no target type for the collection expression.

    .. which I took to mean that, because .Select is an extension method on IEnumerable, the engine was unable to infer whether the collection should be a list, array, or some other type of collection.

    It seems reasonable to have it default to Array if it's ambiguous, maybe there's a downside I'm not aware of.

voidUpdate  3 days ago

I love LINQ, maybe a little too much. I can end up writing monster oneliners to manipulate data in just the right way. I love list comprehensions in python too, since they can work in similar ways

gibibit  2 days ago

For reference, Rust provides a similar experience

    let names = ["Peter", "Julia", "Xi"];
    names
        .map(|name| format!("Hello, {name}"))
        .iter()
        .for_each(|greeting| println!("{greeting}! Enjoy your Rust"));