# Byte Sequences
This crate provides some utility to create byte sequences like ApiKeys or SessionIds.
It contains a macro that lets you specify the name and length in bytes of the sequence.
The macro than creates a struct that has following methods
```rust
fn generate_new() -> Self
fn to_string() -> String
fn check(key: &str) -> std::result::Result<Self, failure::Error>;
```
It also implements `Display`, `Debug`, `serde::Serialize`, `serde::Deserialize`, `PartialOrd`, `Ord`, `PartialEq`, `Eq`, `Clone`, `Copy` and `Hash`;
Complete example:
```rust
#[macro_use]
extern crate byte_sequence;
extern crate rand;
use serde;
use std;
use byte_sequence::Checkable;
byte_seq!(ApiKey; 32);
#[test]
fn example() {
// Creates a new ApiKey containing 32 random bytes using a thread_rng
let key = ApiKey::generate_new();
// The to_string method creates a hex encoded string:
// i.e. 'BBC47F308F3D02C3C6C3D6C9555296A64407FE72AD92DE8C7344D610CFFABF67'
assert_eq!(key.to_string().len(), 64);
// you can also do it the other way around: Parse a string into an ApiKey
let key = ApiKey::check("BBC47F308F3D02C3C6C3D6C9555296A64407FE72AD92DE8C7344D610CFFABF67").unwrap();
assert_eq!(key.to_string(), "BBC47F308F3D02C3C6C3D6C9555296A64407FE72AD92DE8C7344D610CFFABF67");
}
```
You can also extend the generated structs.
For example add a public part of the ApiKey:
```rust
impl ApiKey {
pub fn public_part(&self) -> PublicApiKey {
let mut pub_data = [0u8; 8];
pub_data.copy_from_slice(&self.0[0..8]);
PublicApiKey(pub_data)
}
}
```