Edit Chapter 09

[edilmedeiros]

I can see people getting confused with this, but I believe you did a great job explaining the copy of references. I tried to expand a bit and explain step by step what is happening. Please see the individual commits, in particular the top one.

[sb1752]

Hm given this long paragraph, might make sense to add another diagram in here. Let me look into creating one that could help.

[edilmedeiros]

I was uncertain if you would approve this, but since you said there was some people with difficulty here I added anyway.

[sb1752]

Yeah i'm wondering if it makes more sense to replace all the extra text with a helpful diagram instead. So it doesn't feel too overwhelming to read.

[sb1752]

So I did a little investigation here and I believe I'm explaining this slightly incorrectly, though the general idea is still the same.

This line for example:
println!("transaction_bytes memory address before reading {:p}", transaction_bytes); will print the memory address of the internal buffer (the heap location), not the structure itself. If we want the structure itself, we'd have to add the & in front and print the memory address of &transaction_bytes.

This makes sense since when this memory address updates, it's consistently 4 greater than the previous memory address.

So I updated the two diagrams that we can use to show what's going on here. I don't think the transaction_bytes actually gets updated to point to the new bytes_slice. That bytes_slice structure remains the same and simply points to a new location on the heap.

These are the two diagrams I have. Let me know what you think.

[sb1752]

Here is a PR I made to correct that explanation. Included the diagrams as well: #26

[edilmedeiros]

The new diagrams are a huge improvement. I tend to be more verbose and explain the figures I add in my texts anyhow, but I don't want to disturb your style. Based on people's difficulties and feedback, do you believe the diagrams are enough or there are more concept they are finding hard to grasp?

[sb1752]

Yeah I'm not sure. I think the diagrams might do a lot of heavy lifting though. They def helped me quite a bit when reading the Programming Rust book.