## ecommerce – Is there a standard for “virtual receipts”, and is it actually used anywhere?

I just got another e-mail from my food store after I had placed an order. It has no plaintext version, only a HTML one. Only with extreme amounts of efforts from me could I parse out the products and their individual prices and quantities… until they change their e-mails the next time.

I currently “only” parse out the delivery date/time, the total price for the order and the order id. Which is insanity.

Is there really no “digital receipt” standard? They seem to have no hidden JSON/CSV blob anywhere in their e-mail, or even manually downloadable from their website when logged in. How is one supposed to actually make a local database of what they buy and the prices and stuff? Even just figuring out how to parse their e-mails for the total price was quite a bit of work, and I’m certain that almost nobody out there does this.

How come this was apparently overlooked, in spite of being such an important and basic thing for “e-commerce”? Am I really expected to manually input all of this data or spend countless hours figuring out their broken HTML blob and keep updating it whenever they change their e-mails, and do this for every single store I ever buy anything from?

I strongly suspect that there is some standard, probably released as an RFC in 1997 or something, but nobody wants to implement it because it means “giving away control” in their eyes?

## encoding scheme – Is there a way to store an arbitrarily big BigInt in a bit sequence, only later to convert it into a standard BigInt structure?

I am trying to imagine a way of encoding a BigInt into a bit stream, so that it is literally just a sequence of bits. Then upon decoding this bit stream, you would generate the standard BigInt sort of data structure (array of small integers with a sign). How could you encode the BigInt as a sequence of bits, and how would you decode it? I don’t see how to properly perform the bitwise manipulations or how to encode an arbitrary number in bits larger than 32 or 64. If a language is required then I would be doing this in JavaScript.

For instance, this takes bytes and converts it into a single bit stream:

``````function arrayOfBytesTo32Int(map) {
return map(0) << 24
| map(1) << 16
| map(2) << 8
| map(3)
}
``````

How would you do that same sort of thing for arbitrarily long bit sequences?

## coding style – which of the standard Python libraries consider to be “well written”

Coming from a lot of experience writing Java & C# code in the past, I find Python code to be very confusing in terms of design and style.
I’m not referring to the Python syntax per se, rather than the choices Python developers make to better organize their code in a maintainable way.

I did found google style guide to be helpful to some extent, but it’s still missing a lot of structural guidance with respect to what consider to be Pythonic and what not.

for example, what consider to be the best practice for splitting the code to different packagesmodules etc? should consts, enums & exceptions reside in their own modules or should we put them all in the same file (module)? what’s the verdict for module-level functions?

I’d like to go through some well-written Python standard lib code so I could use it as a reference.

## Seeking feedback on my cover letter for UK standard visitor visa application

I am scheduled to apply for a UK visitor visa on 13 July and have stated that I plan to stay for the whole six months. I’ve decided to include a cover letter to explain the circumstances of my request. I’d appreciate it if you could provide feedback on the below text:

## How to set C++ language standard for VS2019 in an Unreal project?

I am trying to a simple thing, just like that, in a header file;

``````#include <filesystem>
#include <iostream>

namespace fs = std::filesystem;

``````

And IntelliSense goes:
`namespace std has no member filesystem`.

Okay no worries, it’s an easy fix.
Just set the C++ language standard in the propery pages…

Well, it turns out it isn’t, it’s not an option in Unreal VS project. Tried typing in search bar, View -> Property pages, but no luck.

Okay let’s try doing the whole thing in a console project first.

Same message from IntelliSense as before.

Ok, no worries, I found this.

I found my settings under: Project > projectname Properties

And voila, the console app works.

Let’s try it in the Unreal project.

Well, well… My options are limited here.

I had a look around in the project settings as well:

How do I get this filesystem header work with my project?

## Current industry standard with regards to C macros

I have read from several authors that macros in C should be avoided whenever possible, and use `inline` functions instead. It’s true that `inline` only ‘requests’ the compiler to replace the function call by ‘expand’ the function body in the calling place, however my understanding is that, if a modern C compiler ‘doesn’t want to inline’ a function, probably it’s because it shouldn’t be.

However, I still see an intensive use of macros and `#ifdef` etc. directives in ‘modern’ open source projects, such as `FreeRTOS`, `Zephyr` and many others.

Does this mean that the industry has reconsidered its position with regards to macros? Is there any good reason to use macros instead of inline functions?

## sharepoint online – How to pull data from another list, without duplicates without custom code on a “Standard Calendar” List?

I have a “Standard Calander” list, which I have 3 fields where I want to pull their data from an existing SPO list. The problem is, that in our instance of SPO won’t allow me to use any scripting to filter out the duplicates that would be part of the 3 fields.

How can I pull data from a custom list, but not pull duplicates without special scripting? It seems like SPO Calendar doesn’t allow editing the NewForm.aspx in PowerTools so I’m at a loss as to how to do this.

The requirements I’m under:

The users must be able to sync their calendars to the list.
The users must be able to download a meeting from the calendar and upload the meeting to their Outlook Calendar for individual meetings also.
The users must be able to be notified (they WANT to have their calendars updated when the SPO Calendar is updated with no intervention from them) when changes are made to the calendar or meeting.
The users (want) the drop downs to be “filtered” based on the choice of the dropdown before it.
Example:

Value Stream

VS A
VS B
VS C
ART

1-When I choose “VS A” from the VS, only ARTS which report to the VS appear as an option

2-When I choose the “ART” from the “ART List”, only teams that report to that ART appear as an option.

Team

A
B
C

## Not sending all headers in standard browser get request

I’m typing the url into the top bar of chrome (happens no matter what browser I’m on and doesn’t happen for any other people’s computer on the same network) but www.website.com doesn’t send all the request headers needed to get to the site, doesn’t even seem to be getting to cloudflare and I have no idea why this is happening. The site works fine on website.com and dev.website.com which makes it even more confusing. This screenshot shows what headers are being sent so you can compare it with any other site you can access. Does anyone have any idea why this would be happening on only www version of the site and no others?

## probability or statistics – Calculate combined standard deviation

If I have a data that I fit with `NonlinearModelfit` that fits a data based on two fitting parameters, `c1` and `c2`.

When I used `nlm("ParameterTable") // Quiet` I get the following table:

If I have an equation such as:

`eq = (2.303*((70 + 273.15)^2)*(c1/c2))/1000`

Is there any code (as opposed to doing it manually) I can use to calculate the value of `eq` with the combined standard deviation based on the standard deviations of `c1` and `c2` from the table?

Thank you!

## differential algebra – Books/Lecture notes which contrast Risch algorithm with basic standard procedure of finding an antiderivative

I vaguely remember a book/some lecture notes which introduce integration algorithms such as Risch algorithm by first giving a list of quasi-algorithmic way of evaluating symbolic integrals. (For example, when integrating a rational trignometric function, use one of the substitutions $$u=sin theta$$, $$u=cos theta, u=tan frac12theta$$ and so on; when dealing with a rational function, express it in partial fractions.) Then it goes on to develop the theory of differential algebra.

I could not find the text now. After searching for quite a few sources, I have not found any books which contrast those easy procedures with Risch algorithm.

Where could I find a book which is similar to the one I describe above?