structopt-toml

An default value loader from TOML for structopt. It combinates with structopt.

Usage

This crate must be used with serde, serde_derive, structopt, and toml explicitly.

[dependencies]
serde          = "1.0.33"
serde_derive   = "1.0.33"
structopt      = "0.2.5"
structopt-toml = "0.2.4"
toml           = "0.4.5"

Example

If derive(Deserialize), derive(StructOptToml) and serde(default) are added to the struct with derive(StructOpt), some functions like from_args_with_toml can be used.

#[macro_use]
extern crate serde_derive;
#[macro_use]
extern crate structopt;
#[macro_use]
extern crate structopt_toml;
extern crate toml;

use structopt::StructOpt;
use structopt_toml::StructOptToml;

#[derive(Debug, Deserialize, StructOpt, StructOptToml)]
#[serde(default)]
struct Opt {
    #[structopt(default_value = "0", short = "a")] a: i32,
    #[structopt(default_value = "0", short = "b")] b: i32,
}

fn main() {
    let toml_str = r#"
        a = 10
    "#;
    let opt = Opt::from_args_with_toml(toml_str).expect("toml parse failed");
    println!("a:{}", opt.a);
    println!("b:{}", opt.b);
}

The execution result is below.

$ ./example
a:10        // value from TOML string
b:0         // value from default_value of structopt

$ ./example -a 20
a:20        // value from command line argument
b:0