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Given the following Python scripts:

a.py:

from multiprocessing spawn:

The parent process starts a fresh python interpreter process. The child process will only inherit those resources necessary to run the process objects run() method. In particular, unnecessary file descriptors and handles from the parent process will not be inherited. Starting a process using this method is rather slow compared to using fork or forkserver. [Available on Unix and Windows. The default on Windows and macOS.]

currently in my classes we were learning how we can handle signals in C. I found it very interesting so I was messing around with it to try and learn it nicely.
Here's the problem: I wanted to make a program that reads from stdin on an infinite loop and writes whatever is inputed in to a file. When I want it to stop I would just use CTRL + C and terminate the program.
I wanted to mess around with the signal function to make this terminate more gracefully, however it doesn't work. Can anyone tell me how to get the desired behavior?
This is my code:

I thought it's easy to deploy a python api project to somewhere. BUT I was wrong, I cannot deploy to any platforms.

So far I have tried:

1. Azure, Webapp and Function App
2. PythonAnywhere
3. Heroku

They all have issues when I'm trying to install dependency packages for this one: scikit-fmm

here is the error message:

Python Version is 3.7.10 Linux

I'm writing a project where you start the server in one terminal, and in other terminals that are clients you can send messages from one user to another using FIFO pipes. Server creates FIFO pipe that reads messages from clients. Client creates FIFO pipe to read messages from server.

In one terminal to start the server I type ./projectname --start and in client i type ./projectname --login nickname. When I close the client terminal my server receives segmentation fault(core dumped) error message. I tried to get rid of this in every possible way I know for x hours. How can it be fixed?

I have also tried to register users using the void verifyloginclient(char *login) function but parent proccess is unable to receive information from child and is stuck in infinite while(1) sending some message to server that also crashes server with segmentation fault so it's commented for now.

I am trying to have a process read both from a named pipe and some unnamed pipes. First I have a main process that creates a child process and then initializes a named pipe that waits for data from the terminal to send to the named pipe:

I have 2 data types that I use for the representation of natural numbers in the unary system

I am writing low level 2D/3D rendering engine as a part of display driver for MCU platform in C++ and I hit a wall with perspective projection in 3D and face culling.

Lets assume my 3D engine is using M,V,P matrices (in the same manner as Model,View and Projection matrices in OpenGL fixed pipeline).

The idea is to convert rasterized face normal into view local coordinates (using MV) and test the sign of coordinate corresponding to view direction. The same can be done with dot product between camera view direction and the normal itself. And according to sign either rasterize or skip face. This works well for parallel rays projections ... however with perspective projections this leads to false positives (you can see faces "visually" tilted away up to some angle).

For filled surfaces this poses only performance hit as depth buffer remedies the artifacts so render looks like it should. However wire frame is a problem:

The remedy is to transform vertexes of face by MVP and do the perspective divide. And then re-compute the normal from the result and use that for face culling:

However that is a lot of more operations which on slow platforms like MCU could pose a performance problem. So my question is:

If it is possible How to use face normal for back face culling safely?

I have tried to transform the normal locally by transforming face center and its small displacement in normal direction by MVP with perspective divide and then recomputing the normal from these 2 points. Still twice the operations then using directly normal but better than 3x. However result was not correct (looked almost identical to using normal directly).

I am thinking of somehow computing the tilt angle for given projection / location and test the:

I known that r -> a is a Functor in a, and that fmap = (.) for it.

This means that when I do fmap f g, with g :: r -> a, f is applied to the result of g as soon as the latter is fed with a value of type r. However, if a is a function type, e.g. a unary function b -> c, then there's a difference between applying f to that function (which is what happens in reality) and applying f to the eventual result of g (which could be desirable in some cases; couldn't it?).

How do I map on the eventual result of g? In this case of g :: r -> b -> c it seems easy, I can just uncurry $ fmap f $ curry g. But what if also c is a function type?

Or, in other words, how do I map on the final result of multi-variable function? Is the curry/uncurry trick necessary/doable in general?

(Related question here.)

As it's apparent from comments/answers, I have not realized I was essentially asking the same question I've already asked some days ago. Probably it was not apparent to me because of how I got here. Essentially, what led me to ask this question is another one storming in my head:

If I can use liftA2 (&&), liftA2 (||), and similar to combine unary predicates, how do I combine binary predicates? To answer to this, I played around a bit in GHCi, and came up with this