forkjoin

isFunction = (f) -> 'function' is typeof f isFuture = (a) -> if a?.isFuture then yes else no head = (a) -> if a a[0] else undefined async = (f) -> (args..., go) -> try go null, f.apply null, args catch error go error fork = (continuable, args=[]) -> throw new Error "Not a function." unless isFunction continuable _continuations = [] link = (go) -> if isFunction go found = no for continuation in _continuations if continuation is go found = yes unless found _continuations.push go return propagate = -> while go = _continuations.shift() if self.rejected go self.error else go null, self.result return self = (go) -> join [ self ], (error, results) -> if error go error else go null, head results self.evaluate = (go) -> link go if self.settled # proceed with cached error/result do propagate else if self.evaluating # no op else self.evaluating = yes join args, (error, args) -> if error self.error = error self.fulfilled = no self.rejected = yes self.evaluating = no do propagate else continuable.apply null, args.concat (error, result) -> if error self.error = error self.fulfilled = no self.rejected = yes self.evaluating = no do propagate else self.result = result self.fulfilled = yes self.rejected = no self.evaluating = no do propagate self.settled = yes self.pending = no self.method = continuable self.args = args self.fulfilled = no self.rejected = no self.settled = no self.pending = yes self.evaluating = no self.isFuture = yes self join = (args, go) -> return go null, [] if args.length is 0 tasks = [] results = [] for arg, i in args if isFuture arg tasks.push future: arg, resultIndex: i else results[i] = arg return go null, results if tasks.length is 0 resultCount = 0 settled = no tasks.forEach (task) -> task.future.evaluate (error, result) -> return if settled if error settled = yes go error else join [ result ], (error, localResults) -> if error settled = yes go error else results[task.resultIndex] = head localResults resultCount++ if resultCount is tasks.length settled = yes go null, results return return resolve = (args..., go) -> join args, (error, results) -> go.apply null, [error].concat results createTask = (continuable) -> throw new Error "Not a function." unless isFunction continuable (args...) -> fork continuable, args # [ Future<T> ] -> Future<[T]> seq = (_futures) -> fork (go) -> futures = _futures.slice 0 results = [] next = -> future = futures.shift() if future future (error, result) -> if error go error else results.push result do next else go null, results return do next return # [ Future<T> ] -> Future<[T]> collect = (futures) -> fork join, [ futures ] # ([T], ((T) -> Future<T>)) -> Future<[T]> map = (array, defer) -> collect (defer element for element in array) # ([T], ((T) -> Future<T>)) -> Future<[T]> forEach = (array, defer) -> seq (defer element for element in array) lift = (futures..., f) -> fork (go) -> join futures, (error, results) -> if error go error else go null, f.apply null, results forkjoin = async: async task: createTask fork: (continuable, args...) -> fork continuable, args join: join isFuture: isFuture resolve: resolve seq: seq collect: collect map: map forEach: forEach lift: lift if window? then window.forkjoin = forkjoin else module.exports = forkjoin