Enum to &str / &str to Enum - rust

Question

Wondering if there's a "proper" way of converting an Enum to a &str and back.
The problem I'm trying to solve:
In the clap crate, args/subcommands are defined and identified by &strs. (Which I'm assuming don't fully take advantage of the type checker.) I'd like to pass a Command Enum to my application instead of a &str which would be verified by the type-checker and also save me from typing (typo-ing?) strings all over the place.
This is what I came up with from searching StackOverflow and std:
use std::str::FromStr;
#[derive(Debug, Clone, Copy, PartialEq)]
pub enum Command {
EatCake,
MakeCake,
}
impl FromStr for Command {
type Err = ();
fn from_str(s: &str) -> std::result::Result<Self, Self::Err> {
match s.to_ascii_lowercase().as_str() {
"eat-cake" => Ok(Self::EatCake),
"make-cake" => Ok(Self::MakeCake),
_ => Err(()),
}
}
}
impl<'a> From<Command> for &'a str {
fn from(c: Command) -> Self {
match c {
Command::EatCake => "eat-cake",
Command::MakeCake => "make-cake",
}
}
}
fn main() {
let command_from_str: Command = "eat-cake".to_owned().parse().unwrap();
let str_from_command: &str = command_from_str.into();
assert_eq!(command_from_str, Command::EatCake);
assert_eq!(str_from_command, "eat-cake");
}
And here's a working playground:
https://play.rust-lang.org/?version=stable&mode=debug&edition=2018&gist=b5e9ac450fd6a79b855306e96d4707fa
Here's an abridged version of what I'm running in clap.
let matches = App::new("cake")
.setting(AppSettings::SubcommandRequiredElseHelp)
// ...
.subcommand(
SubCommand::with_name(Command::MakeCake.into())
// ...
)
.subcommand(
SubCommand::with_name(Command::EatCake.into())
// ...
)
.get_matches();
It seems to work, but I'm not sure if I'm missing something / a bigger picture.
Related:
How to use an internal library Enum for Clap Args
How do I return an error within match statement while implementing from_str in rust?
Thanks!

Answer 1

The strum crate may save you some work. Using strum I was able to get the simple main() you have to work without any additional From implementations.
use strum_macros::{Display, EnumString, IntoStaticStr};
#[derive(Debug, Clone, Copy, PartialEq)]
#[derive(Display, EnumString, IntoStaticStr)] // strum macros.
pub enum Command {
#[strum(serialize = "eat-cake")]
EatCake,
#[strum(serialize = "make-cake")]
MakeCake,
}
fn main() {
let command_from_str: Command = "eat-cake".to_owned().parse().unwrap();
let str_from_command: &str = command_from_str.into();
assert_eq!(command_from_str, Command::EatCake);
assert_eq!(str_from_command, "eat-cake");
}