Passing multiple parameters to a map

[v1gnesh]

Hello,

Firstly, thank you for this excellent work.
Seriously look forward to how much better this is going to get.

Request your inputs/help please on the following use case:

pub struct H {
  a: u16,
  #[deku(map = "H::morph")]
  b: String,
}

impl H {
  pub fn morph(bytes: [u8; 4]) -> Result<String, DekuError> {
    // here I use both bytes & len
  }
}

What I want to do is use something like #[deku(map = "H::morph(4)")] to specify how many bytes to take in into the function.
That is, is there a way to pass the 4 to the fn morph from the #[deku(map ...)] definition?

Thank you!

[v1gnesh]

I noticed that there's a bytes_read attribute.
Can this be updated to make it accept a number directly, rather than having to specify it through another field in the same struct?
That would be awesome; will help my current situation.

[v1gnesh]

It worked with a literal.

pub struct H {
  a: u16,
  #[deku(map="morph", bytes_read="4")]
  b: String,
}

pub fn morph(bytes: &[u8]) -> Result<String, DekuError> {
   let len = bytes.len();
  // do stuff
  Ok(whatever)
}