keyword continue for methods to make code more clean

[amrmostafa800]

edit : i understand this will been really bad design (edited)
what about make it like normal method and only when return in it like return in original method
sorry for bad english

   static async Task<int> OriginalMethodAsync()
    {
        bool isOk = true;
        await ContinueMethod(number);
        return 42;
    }

    static continue async Task<int> ContinueMethod(bool result) // its return type must been same Caller method return type
    {
		if(result)
		{
		 return 8; // if return here like return in Caller Method
		}
		 // if dont return Caller Method will continue normal
    }

[HaloFour]

See: #1413

[amrmostafa800]

can please give me example to do same thing in example up with inlining or anything in c# ?

[HaloFour]

You can't, C# doesn't have a feature like this. Method inlining is a feature of the runtime and the team has not expressed interest in adding macros. My opinion is that this feature would not be considered either, and that the ability to reference identifiers that do not actually exist within the method would not be considered a positive thing.

[amrmostafa800]

ok thank you cant do this using code generation ? and make compiler ignore continue method (bycouse code generator will convert it and original method to one method) ? to do this at build time (i still dont know how code generation work but i think maybe can do thing like this using it ?)

[HaloFour]

A source generator can emit additional methods into the current class, assuming it's marked as partial.

There is another proposal to support method interception, which would let you replace one method invocation with another: #7009

Neither of these options let you rewrite the source within a specific method, though.

[amrmostafa800]

ok thanks for help

[TahirAhmadov]

I think you want a complicated operation broken up into multiple methods, while sharing the state of the overall operation between these methods. I doubt this has much to do with inlining or performance per se.
The way I understand your request - it's a regular (not necessarily a very frequent) pattern. Currently I declare a type to hold the state, most likely a struct, then pass it around by ref between the methods in your group which form the single "big" operation. At run time, all the overhead is optimized away and the whole thing works just like if you wrote a giant method - while allowing you to write code in a more modular manner, which has tons of benefits. The downside here is that you lose (get degraded) the language assignment and NRT analysis.
You also want to consider extracting parts of the functionality into completely separate types - this may not be always possible, but it's the first step.

PS. There are also #region directives which can help some times.
PPS. Also local functions may help. The advantage of the latter two approaches is that you get the full flow analysis; the downside is that you still have a huge method - it's somewhat more readable/ maintainable - but I don't like "huge" methods regardless of the "lipstick" you put on it.

[TahirAhmadov]

For return situations like that, you need a wrapper return type on the "child" methods like Result<T> - basically:

int Foo()
{
  var state = new FooState { ... };
  if(Foo_PartA(ref state) is {} t && t.HasResult) return t.Result;
  return 456;
}
struct FooState
{
}
Result<int> Foo_PartA(ref FooState state)
{
  return new(123);
}

[amrmostafa800]

thanks but this not same i mean (i only ask for it for more clean code) i edit up - you thing this good or still bad idea ?
and thanks for tell me about Result class

[TahirAhmadov]

I think given that my code snippet is already valid language, it's very unlikely that they would invest into making it even simpler in the direction of what you are proposing. Especially so because while it is a pattern that I have to deal with from time to time, it's not a frequent pattern.
Also, there are questions about your proposal, like how do you link these methods together in a "group"?

[amrmostafa800]

i mean method can only been inside other method direct cant been inside () can used for validation (i know can just make it inside if but it look good more with this why i think ?)

the resson is can used in asp.net controller for clean validation (without need to make if) validation method will do everything

[amrmostafa800]

maybe can do it when Interceptors released as package