Note that one interesting aspect of using struct{} for the type pushed to a channel (as opposed to int or bool), is that the size of an empty struct is… 0! See the recent article “The empty struct” (March 2014) by Dave Cheney. You can create as many struct{} as you want (struct{}{}) to push … Read more
From the Go Language Spec: For a channel c, the built-in function close(c) records that no more values will be sent on the channel. It is an error if c is a receive-only channel. Sending to or closing a closed channel causes a run-time panic. Closing the nil channel also causes a run-time panic. After … Read more
Your monitorWorker never dies. When all the workers finish, it continues to wait on cs. This deadlocks because nothing else will ever send on cs and therefore wg will never reach 0. A possible fix is to have the monitor close the channel when all workers finish. If the for loop is in main, it … Read more
The boolean variable ok returned by a receive operator indicates whether the received value was sent on the channel (true) or is a zero value returned because the channel is closed and empty (false). The for loop terminates when some other part of the Go program closes the fromServer or the fromUser channel. In that … Read more
Use img.shape It provides you the shape of img in all directions. ie number of rows, number of columns for a 2D array (grayscale image). For 3D array, it gives you number of channels also. So if len(img.shape) gives you two, it has a single channel. If len(img.shape) gives you three, third element gives you … Read more
I think what you are looking for is Control.Concurrent.Chan from Base. I haven’t found it to be any different from go’s chans other then the obvious haskellifications. Channels aren’t something that is special to go, have a look at the wiki page about it. Channels are part of a more general concept called communicating sequential … Read more
The problem with Fn() is that you can call it multiple times. If you moved out of a captured value, that value would not be available anymore at the next call. You need a FnOnce() to make sure calling the closure also moves out of it, so it’s gone and can’t be called again. There’s … Read more
The statement var chans [5]chan int would allocate an array of size 5, but all the channels would be nil. One way would be to use a slice literal: var chans = []chan int { make(chan int), make(chan int), make(chan int), make(chan int), make(chan int), } If you don’t want to repeat yourself, you would … Read more
Change the order from ~/.condarc so that defaults the first channel as channels: – defaults – conda-forge and add this line to it channel_priority: true or run the following code in command-line conda config –set channel_priority true then again run conda update –all Good Luck Edited for new versions of conda. According to conda doc … Read more
You can’t. The rule of thumb here is that only writers should close channels, this way you know that you shouldn’t write to that channel anymore. Some simple code would look like this: for i := 0; i < 100; i++ { value := calculateSomeValue() channel <- value } close(channel) //indicate that we will no … Read more