STX | C++17 & C++ 20 error-handling and utility extensions | Architecture library

So I'm trying to multiply by using add and shift. I want to store the multiplicand in the accumulator and the multiplicand in the X-register. I genuinely don't know why my code isn't working but I suspect its because of the multiplicand being in the accumulator and putting the product in a separate register.

Here is my code so far:

Why/how function string.Substring treats "\u0002" as a one sign? I mean ok, "\u0002" is a "character" STX.

1. \u says that is unicode
2. Character and string processing in C# uses Unicode encoding. The char type represents a UTF-16 code unit, and the string type represents a sequence of UTF-16 code units.

Code checks if preffix suffics is correct. Data length does not matter. Prefix is STX , suffix is ETX added do data string. How to do this(code below) explicitly without a doubt?

I am trying to understand macros inside the Racket environment. The concept intrigues me.

After writing this definition on Dr. Racket's definition window:

I have problems to create jsonb through Postgres 10. I need to extract the value in columns and construct a json format output. I managed to extract the value but having problem to construct it into JSON format

make-variable-transformer (or make-set!-transformer, as it is called in Racket) can work with identifiers hardcoded in the literal list of the macro definition. The following example with set! invariably comes up when variable transformers are mentioned:

I'm trying to test some probes connected via USB on an Linux device using Perl 5.28 and Linux (Debian 8). When I read out a large file buffer of the probe, often none readable ASCII signs occur like \0 or \x02. I want to translate these signs into readable tagged text. I've written a small subroutine, but it seems to me a little bit clunky for large translation list to test every entry. Is there a better way to do that?

Example script

I have a Python program that is receiving data from a UDP socket. Python is reading it as binary data.

Each datagram should start with the STX character (0x02) and end with the ETX character (0x03). I want my code to test the first and last character and, if they are correct, to strip them before passing the rest of the data out of my function to be further processed by the calling function.

I believe I can test the first character with data[0].

How can I get the length of the data so as to test the last character?

How can I get a "substring" of the data?

I am tempted to decode it to a string, but suspect that involves extra overhead and anyway, as a Python novice, I have no idea how.

I'm not sure exactly how wrapping works with the indexed x and y address modes. The documentation that I've found is clear that the indexing part is wrapped around within the zero page, but what about the actual dereferenced 16bit address, is that constrained to the zero page as well?

Let's say I have this code:

For days I'm trying to figure out the reason for the problem I have with this code: