Since promises are apparently cool right now, I feel like I should raise this issue.
We shouldn't really have blocking HTTP requests. Can we have the verbs return a promise object, such that I can do:
Curl.get("http://jsonip.com").then((res) -> println(res.text))Then would take three arguments: onResolved, onError, and onProgress.
I would express it like this:
type Promise
then::Function
resolved_callbacks::Vector
rejected_callbacks::Vector
progress_callbacks::Vector
resolve::Function
reject::Function
progress::Function
function then(on_resolved, on_error, on_progress)
# push callbacks into queues
end
function resolve(value)
# if no handlers left return
# shift handler off queue
# invoke handler with value
# recurse
end
function reject(error)
# if no handlers left return
# shift handler off queue
# invoke handler with value
# recurse
end
function progress(value)
# if no handlers left return
# shift handler off queue
# invoke handler with value
# recurse
end
function Promise()
new(then, [], [], [], resolve, reject, progress)
end
end
get = function (url)
promise = Promise()
on_complete(data) = promise.resolve
on_error(error) = promise.reject
on_progress(data) = promise.progress
do_curl() # with appropriate arguments
promise;
end
Of course that doesn't allow us to chain then calls, but in general I find chaining to be very difficult in Julia. There may be a way to do it. We could also just pass in handlers as a vector of functions instead of just one function.
Open to other approaches too.
Since promises are apparently cool right now, I feel like I should raise this issue.
We shouldn't really have blocking HTTP requests. Can we have the verbs return a promise object, such that I can do:
Then would take three arguments: onResolved, onError, and onProgress.
I would express it like this:
type Promise then::Function resolved_callbacks::Vector rejected_callbacks::Vector progress_callbacks::Vector resolve::Function reject::Function progress::Function function then(on_resolved, on_error, on_progress) # push callbacks into queues end function resolve(value) # if no handlers left return # shift handler off queue # invoke handler with value # recurse end function reject(error) # if no handlers left return # shift handler off queue # invoke handler with value # recurse end function progress(value) # if no handlers left return # shift handler off queue # invoke handler with value # recurse end function Promise() new(then, [], [], [], resolve, reject, progress) end end get = function (url) promise = Promise() on_complete(data) = promise.resolve on_error(error) = promise.reject on_progress(data) = promise.progress do_curl() # with appropriate arguments promise; endOf course that doesn't allow us to chain
thencalls, but in general I find chaining to be very difficult in Julia. There may be a way to do it. We could also just pass in handlers as a vector of functions instead of just one function.Open to other approaches too.