Add Extended Inquiry Response (EIR) parser.

[ruediger]

An attempt at adding a parser for EIR.

[laptou]

Hello, and thanks for the contribution :) I have some notes.

[laptou]

What's the purpose of these two lines?

[ruediger]

I had to restore buf after moving it earlier. Otherwise I get the following error.

error[E0382]: borrow of moved value: `buf`
   --> src/eir.rs:105:11
    |
102 | pub fn parse_eir<T: Buf>(mut buf: T) -> Result<EIR, EIRError> {
    |                          ------- move occurs because `buf` has type `T`, which does not implement the `Copy` trait
...
105 |     while buf.has_remaining() {
    |           ^^^ value borrowed here after move
...
121 |         let mut data = buf.take((len - 1).into());
    |                        --- value moved here, in previous iteration of loop
    |
help: consider further restricting this bound
    |
102 | pub fn parse_eir<T: Buf + Copy>(mut buf: T) -> Result<EIR, EIRError> {
    |                         ^^^^^^

error: aborting due to previous error

I'm fairly new to Rust. So there might be an obvious way of doing this I'm missing.

[laptou]

It's not really clear why you need to call buf.take(). Avoiding .take() would solve the problem, as .take() is the call that moves buf. You can still do all of the bounds checking that you do later in the loop using just len, and if you need to create a contiguous series of bytes then you can do buf.copy_to_bytes().

Note that copy_to_bytes() was added in bytes v0.6; you will need to rebase your branch against master.

[laptou]

Consider making this EIR type represent a single EIR tag, and then return a Result<Vec<EIR>> from parse_eir.

Then you could write EIR as a tagged enum:

#[derive(Debug)]
#[non_exahustive]
pub enum EIR {
    Flags(BitFlags<EIRFlags>),
    Uuid16(Vec<u16>),
    Uuid32(Vec<u32>),
    // ...
}

[ruediger]

Yes, I was wondering what the best API would be here. Enums and Vec (or maybe HashSet?) might make it a bit harder to match. But it feels clunky having a struct full of optionals. I'll try with Enums and see how it goes.

[ruediger]

An attempt at changing the return type to Vec: ruediger@cc91569 Please take a look if you prefer this style.

[laptou]

Looks good! Thank you, and please keep it up. One note: EIR::Name has more than one property, and it's not very obvious what the boolean is for, so maybe consider making the properties of that one named?

  Name { name: String, complete: bool },

Also, should the name be a String or a CString? I don't think the Bluetooth spec says device names have to be in UTF-8, so it might be good to give the end-user a chance to deal with this themselves.