#enums #fields #field

macro maydon

Generating enumation for fields of a struct

1 unstable release

new 0.1.0 Feb 17, 2025

#774 in Procedural macros

Download history 78/week @ 2025-02-12

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MIT/Apache

2MB
58 lines

Rust Uzbekistan's {Maydon}

Field enum generation for struct.

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Motivation

Upon writing some rusty code for CLI config management, I simply declared a struct like this:

#[derive(Debug, Serialize, Deserialize)]
pub struct Config {
    pub url: String,
    pub port: u16,
    pub database_url: String,
    pub threads: u16,
}

Also, in order to have set function with proper typed selection, I declared another enum named Field:

pub enum Field {
    Url,
    Port,
    Database,
    Unknown,
    Threads,
}

The thing is, I wanted to automate creation of enum generation. Ordinary macros wouldn't be a good viable solution, so I wrote maydon from ground up. I might be missing something or prequisites, but this is what I came up with:

use maydon::Maydon;

#[derive(Maydon)]
#[field_name = "Selector"]
pub struct Config {
    pub url: String,
    pub port: u16,
}

// The macro should generate:
fn main() {
    let _ = Selector::Url;
    let _ = Selector::Port;
    let _ = Selector::Unknown;
}

License

This project is licensed under the MIT or Apache-2.0 license - see the LICENSE-MIT or LICENSE-APACHE file for details.

Rust Uzbekistan's {Maydon}

Dependencies