Declare class in one line

[lazyloader]

Sometimes we use really simple classes to demenstrate simple concepts and they contain only one method or field. Instead of this

public class Foo
    {
    public void Bar() => Console.WriteLine("Bar");
    }

we can do this

public class Foo => public void Bar()  => Console.WriteLine("Bar");

And instead of

public class Foo
    {
    public void Bar()  => Console.WriteLine("Bar");
    public int Baz() => Console.WriteLine("Baz");
    }

this:

public class Foo => public void Bar()  => Console.WriteLine("Bar");, public int Baz()  => Console.WriteLine("Baz");;

Ediit added implimentations

[jnm2]

@lazyloader Not even the first example could be legal C# since non-abstract methods must declare bodies.

[lazyloader]

@jnm2 there, added implimentations

[CyrusNajmabadi]

Why is:

public class Foo => public void Bar() => Console.WriteLine("Bar");

better than

public class Foo { public void Bar() => Console.WriteLine("Bar"); }

AFAICT, you save 1 character...

[CyrusNajmabadi]

This case is even weirder:

public class Foo => public void Bar() => Console.WriteLine("Bar");, public int Baz() => Console.WriteLine("Baz");;

Because you can already write:

public class Foo { public void Bar() => Console.WriteLine("Bar"); public int Baz() => Console.WriteLine("Baz"); }

Which is one character fewer! So your 'declare class in one line' proposal actually takes up more space :)

[jnm2]

@lazyloader Now that you've added method bodies, it shows that each of the examples is harder to read than the equivalent multiline syntax. And that's just when every method has a very simple body.

Depending on what you're doing, you might be interested in https://github.com/dotnet/csharplang/blob/master/proposals/records.md#records though. I definitely am!

[lazyloader]

@CyrusNajmabadi Couldn't you have made the same arguement for expression body methods?

public void Foo()
    {
    Console.WriteLine("Foo");
    }

Written as

public void Foo() { Console.WriteLine("Foo"); }

So why bother with

public void Foo() => Console.WriteLine("Foo");

It's cleaner and easier to read, and almost no one declares a function with everything on one line unless they're using =>.

Also => can be used in many contexts now to make something one line, so it's inconistent to not let classes or even namespaces be defined in one line using => syntax

[CyrusNajmabadi]

@CyrusNajmabadi Couldn't you have made the same arguement for expression body methods?

Yes. Bu that wasn't the argument for Expression-Body methods. Expression-body methods came from the fact that we'd already done => for lambdas and then had made them available for properties where they're very useful. i.e. it is a lot nicer to say:

public int Foo => whatever;

Instead of

public int Foo { get { return whatever; } }

Once we already had => it made sense to just make it available in more sensible contexts.

--

So the argument was never "let's reduce methods from void Foo() { Bar(); } to void Foo() => Bar();. It was "we already have this pattern that we allow in many other places. Let's just allow it in more.

--

Also, the 'void' version of => is far less interesting than the non-void version. i.e. the much more compelling case is string Foo() => Bar(); over string Foo() { return Bar(); } which is substantially larger.

[stuartstein777]

F# record style declarations would be nice.

[HaloFour]

@stuartstein777

#39