kurisu-derive

Provides derive(Kurisu) for the Kurisu crate.

The Kurisu derive macro is not meant to do any validation nor display usage for the command line string values. It will only construct kurisu::Arg structs according to a given Rust Struct, and put them within a function get_info_instance wrapped by a once_cell static instance of a kurisu::Info struct.

Example:

use kurisu::*;

#[derive(Debug, Kurisu)]
struct Yargs {
    knots: usize,
}

fn main() {
    let env_vars: Vec<String> = std::env::args().skip(1).collect();

    // The Derive Macro add `from_args` function to the user's struct,
    // `from_args` will normalize the command line values into kurisu::Info.env_args
    let args = Yargs::from_args(&env_vars);

    let knots;
    // This scope is so the mutex guard gets released after
    // we retrieve the information we need.
    {
        // The Derive Macro also add `get_info_instance` function to the user's struct.
        // The Kurisu:Info struct holds all the parsed information the Derive Macro did.
        let info = Yargs::get_info_instance(&env_vars).lock().unwrap();
        knots = info.args.iter().find(|a| a.name == "knots").unwrap().clone();
    }

    // If we assume the current example was called as follow: `mycli --knots 8`
    // We would find that information within the Kurisu::Info struct
    assert_eq!(info.env_args, vec!["--knots=8".to_string()]);
    assert_eq!(knots.value, vec!["8".to_string()]);
    assert_eq!(args.knots, 8);
}

Rust types with specific meaning

isize | Defines value type of an Option or Argument f64 | Defines value type of an Option or Argument Vec | Defines a repetitive Option or Argument

Override default behaviors on main Struct

The struct that drives these behaviors is handled by kurisu::Info, most of the annotation are associated to one of its field.

Example:

    #[derive(Debug, Kurisu)]
    // Only picks the version from Cargo.toml since name & desc are already present
    #[kurisu(name = "yargs", cargo, desc = "some desc here", auto_shorts)]
    /// This text is for the DISCUSSION
    /// section in the use screen
    ///
    /// It can be a very large text
    struct Yargs {}

Override default behaviors on main Struct's fields

The struct that drives these behaviors is handled by kurisu::Arg, most of the annotation are associated to one of its field.

env | field's name | env = "MYSQL_HOST" | By default the field's name is used to look for environment variable match as last resort, this is to change which environment variable is being matched env_prefix | None | env_prefix = "MYSQL_" | Will take the field's name and prefix it and look for a match environment variable required_if | None | required_if = "fieldname" | Will make this option required if the other flag/option is present default | "" | default = "42" | If not present in the command line values, struct field will be assigned this default value instead of default type value exit | None | exit = "my_exit_func" | Local function that triggers std::process::exit() after being executed. A bit like the usage display, it will stop execution at from_args   |   | parse_with = "my_func" | Local function that allows custom parsing for this argument/flag/option

Example:

use std::path::PathBuf;

#[derive(Debug, Kurisu)]
struct Yargs {
    #[kurisu(pos = 1)]
    file: PathBuf,
    #[kurisu(pos)] // Infinite positional argument
    others: String,
    #[kurisu(short, nolong, env_prefix = "MYSQL_")]
    host: String,
    #[kurisu(long = "very-long-flag")]
    more: bool,
    /// description for `crashed` on usage screen
    crashed: bool,
}

License: MIT OR Apache-2.0