The Author Online Book Forums are Moving

The Author Online Book Forums will soon redirect to Manning's liveBook and liveVideo. All book forum content will migrate to liveBook's discussion forum and all video forum content will migrate to liveVideo. Log in to liveBook or liveVideo with your Manning credentials to join the discussion!

Thank you for your engagement in the AoF over the years! We look forward to offering you a more enhanced forum experience.

pminten (16) [Avatar] Offline
(Ok, I said I was going to post every issue in it's own thread, but these are just so small it makes more sense to group them)

Chapter 2 looks great. There are a few points I'd like to raise though:

1. In "2.4.2 Atoms" you describe atoms as similar to symbols in Ruby and enumerations in C/C++. I disagree with the C/C++ part. Atoms don't need to be predeclared and don't map to integers, furthermore atoms with a different name are automatically different. Enumerations on the other hand are more like constants wrapped in a type.

2. In "2.4.5 Immutability" under "Benefits" you say "This in turn makes it possible to perform atomic in-memory operations". I'm not sure "atomic" is the word you are looking for. Atomic refers to making a change that's not observable from the outside, it's either version A or version B but no half-A half-B. However you are not changing anything, you are rebinding. There is no concept of commit or rollback since there is no actual change, only function returning. I understand what you're trying to say but this seems to be a confusing use of terminology.

3. In "2.4.7 Strings" under "Character Lists" you say "In this case, you can convert a binary string to a character list version using the Kernel.to_char_list/1 function. Isn't `String.to_char_list!/1` more appropriate here? It's more explicit about exceptions and avoids calling the List.Chars protocol.

4. In "2.7 Summary" you say "There is no nullability. Atom nil can be used for this purpose.". I'm not quite sure about the terminology but it seems to me that this is effectively nullability.
sjuric (109) [Avatar] Offline
Re: Chapter 2: Various small points
Hi Peter,

Thanks again for the valuable remarks!
I'll probably make a change regarding point 3, and consider other points as well.

Best regards,
JanaG (4) [Avatar] Offline
Re: Chapter 2: Various small points
In 2.3.2 Defining Functions - you mentioned, "A function must always be a part of some module".

I would say A "named" function must always be a part of the some module since an anonymous function/lambda can be defined and run without being part of any module.

Example: greet.exs

greet = fn(name) -> IO.puts "hello #{name}!" end
sjuric (109) [Avatar] Offline
Re: Chapter 2: Various small points
Thank you for this comment.

What you're saying is definitely true, but I must think about whether to change the text or not. If I mention a "named function", then a reader might wonder what kind of other functions exist, so I would have to expand on this as well.

Perhaps it would be better to make this remark later in the chapter, when anonymous functions are introduced.