Now there is another problem. I hope I can write the code like this:
proc ff1(p1: int): Result =
# my db acess code here
......
proc ff2(p1, p2: int): Result =
# my db acess code here
......
proc main() {.async.} =
# async call ff1 with parameter
let r1 = await callAsync(ff1(1))
# async call ff2 with parameter
let r2 = await callAsync(ff2(1, 2))
......
Because we pass the parameter 'ff1(1)' to callAsync, so callAsync must be a
macro like this:
macro callAsync*(p: untyped): untyped {.async.} =
quote do:
proc callme(evt: AsyncEvent): Result =
let s = `p`
evt.trigger()
s
let evt = newAsyncEvent()
let fut = waitEvent(evt)
let val = spawn callme(evt)
await fut
return ^val
But a macro cannot be {.async.}, so I cannot do this.
A limited way to resolve this problem is use an procval, here is the code:
type
Result* = ref object of RootObj
body*: string
Action = proc(): Result
proc waitEvent(evt: AsyncEvent): Future[void] =
let fut = newFuture[void]("callAsync")
addEvent(evt, (fd: AsyncFD) => (fut.complete(); true))
return fut
proc callp(evt: AsyncEvent, p: Action): Result =
let v = p()
evt.trigger()
v
proc callAsync*(p: Action): Future[Result] {.async.} =
let evt = newAsyncEvent()
let fut = waitEvent(evt)
let val = spawn callp(evt, p)
await fut
return ^val
proc ff(): Result =
echo "work"
sleep(1000)
Result(body: "hello")
block:
let val = waitFor callAsync(ff)
echo "future return ", val.body
The limitation is I can only call Action type proc, and I cannot pass the
paramter freely.
Any way to solve the problem? Thanks.
