hey everyone. I have a question about lambdas and ...

# coroutines

[Oleg Shuliak]

hey everyone.
I have a question about lambdas and suspend functions.
This is the code I have:

private suspend fun doWork(
        templateId: FormTemplateId?,
        form: Form?,
        workflow: DraftWorkflow
    ): DraftWorkflow {
        return Pair(templateId, form).fold(
            { formTemplateId, formUpdate ->
                updateUseCase.update(
                    formTemplateId,
                    formUpdate
                )
                workflow.setUrl()
            },
            { formTemplateId ->
                runBlocking {
                    deleteUseCase.delete(formTemplateId)
                }
                workflow
            },
            { formCreate ->
                val newFormId = runBlocking {
                    createUseCase.create(
                        formCreate
                    )
                }
                workflow
                    .setId(newFormId)
            },
            {
                workflow
            }
        )
     }

as you can see doWork() is suspend function, but in lambda this suspend doesn’t work properly anymore.
updateUseCase.update() in this case is a suspend function as well, but compiler gives me an error: Suspension functions can be called only within coroutine body,
So I have to wrap all calls to runBlocking again to get the expected result.
any idea how that can be done without runBlocking?
Thanks in advance 🙏

[gsala]

I guess the problem is that the functions/lambdas given to fold are not suspending.
You can probably remove the fold function and write simple if/else statements instead, assuming that the behavior of fold is easy to inline.

[Oleg Shuliak]

yeah, that makes sense, but I though I could do some trick with fold and make it work 🙂

[Dmitry Khalanskiy [JB]]

If fold can be made an inline function, this will also work.