Introduce new methods to construct subaccount id from an existing AccountIdRef and a prefix

[frol]

I see the following two methods to be useful:

• AccountIdRef::new_subaccount_id(&self, subaccount_name: &str) -> Result<AccountId, ParseAccountError>
• const fn AccountIdRef::new_subaccount_id_or_panic(&self, subaccount_name: &str) -> &AccountIdRef

Here is a usage example:

const ALICE: &AccountIdRef = AccountIdRef::new_or_panic("alice.near");
const ALICE_TEST: &AccountIdRef = ALICE.new_subaccount_id_or_panic("test"); // test.alice.near

Good first issues note:

• Make sure to cover the new method with tests and documentation string with usage examples

[Jujumba]

I'm a bit confused: const fn AccountIdRef::new_subaccount_id_or_panic(&self, subaccount_name: &str) -> AccountId returns AccountId, but usage example explicitly states that the return type is AccountIdRef. Is it me misseeing something, or is there actually a typo?

@frol

[frol]

@Jujumba Good catch! I have just fixed the signature. I expect const-generics to be used at compile time to concatenate the str slices. Here is the crate I would explore using: https://crates.io/crates/constcat

[Jujumba]

@Jujumba Good catch! I have just fixed the signature. I expect const-generics to be used at compile time to concatenate the str slices. Here is the crate I would explore using: https://crates.io/crates/constcat

I'm not sure that it's possible to concatenate these slices at const context. constcat crate requires variables to be defined as const and const-generics don't allow &str type.

@frol

[frol]

const-generics don't allow &str type.

@Jujumba That is not true: https://docs.rs/near-account-id/latest/src/near_account_id/account_id_ref.rs.html#84-88

[Jujumba]

const-generics don't allow &str type.

@Jujumba That is not true: https://docs.rs/near-account-id/latest/src/near_account_id/account_id_ref.rs.html#84-88

Oh, you meant this. Then you are absolutely right. I thought of the following:

pub fn function<const S: &'static str>() {
}