Async/yield and mirrors

[Daniel Morilha]

Hi, is there a way through mirrors api to know if a function has any async/yield modifier. I didn't find anything on the api.  Thanks

[Justin Fagnani]

It shouldn't matter. An async function and a sync function that returns a Future have no externally visible differences. What do you need?

On Mon, Feb 23, 2015 at 9:17 AM, Daniel Morilha <dmor...@gmail.com> wrote:

Hi, is there a way through mirrors api to know if a function has any async/yield modifier. I didn't find anything on the api.  Thanks

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[Daniel Morilha]

I imagined I would hear something along those lines... I was just thinking how to treat them differently and remove the burden from the API user. I will figure out a different way.

Thanks Justin for the prompt answer.

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Daniel Morilha (dmor...@gmail.com)

[Justin Fagnani]

On Mon, Feb 23, 2015 at 9:36 AM, Daniel Morilha <dmor...@gmail.com> wrote:

I imagined I would hear something along those lines... I was just thinking how to treat them differently and remove the burden from the API user. I will figure out a different way.

Ok, I'm now curious in what way you would treat them differently and in what why there's a burden on the user? Can't you just check the return type for Future or Stream?

In what cases do you want to treat Future foo{} and Future foo async {} differently? They aren't actually different.

[Daniel Morilha]

Hi,

checking the return type was something I didn't realize for whatever reason. Thanks Justin. The idea is to create a generic dispatcher and depending on the consumer, run it differently.

[Sean Eagan]

Hi Daniel,

I wrote the `when` package for this use case:

http://pub.dartlang.org/packages/when

It checks whether the return *value* is a Future, instead of the return *type*, which allows:

* avoids mirrors

* doesn't depend on the method author to annotate the return type as a Future (which is not required in dart).

* allows nested potentially-async callbacks

Hope it helps!

Cheers,

Sean