clap/clap_derive/examples/basic.rs
Ed Page d840d5650e fix(derive)!: Rename Clap to Parser.
Before #2005, `Clap` was a special trait that derived all clap traits it
detected were relevant (including an enum getting both `ArgEnum`,
`Clap`, and `Subcommand`).  Now, we have elevated `Clap`, `Args`,
`Subcommand`, and `ArgEnum` to be user facing but the name `Clap` isn't
very descriptive.

This also helps further clarify the relationships so a crate providing
an item to be `#[clap(flatten)]` or `#[clap(subcommand)]` is more likely
to choose the needed trait to derive.

Also, my proposed fix fo #2785 includes making `App` attributes almost
exclusively for `Clap`.  Clarifying the names/roles will help
communicate this.

For prior discussion, see #2583
2021-10-09 20:12:03 -05:00

48 lines
1.3 KiB
Rust

//! A somewhat comprehensive example of a typical `clap_derive` usage.
use clap::{Parser, ValueHint};
use std::path::PathBuf;
/// A basic example
#[derive(Parser, Debug)]
#[clap(name = "basic")]
struct Opt {
// A flag, true if used in the command line. Note doc comment will
// be used for the help message of the flag. The name of the
// argument will be, by default, based on the name of the field.
/// Activate debug mode
#[clap(short, long)]
debug: bool,
// The number of occurrences of the `v/verbose` flag
/// Verbose mode (-v, -vv, -vvv, etc.)
#[clap(short, long, parse(from_occurrences))]
verbose: u8,
/// Set speed
#[clap(short, long, default_value = "42")]
speed: f64,
/// Output file
#[clap(short, long, parse(from_os_str), value_hint = ValueHint::FilePath)]
output: PathBuf,
// the long option will be translated by default to kebab case,
// i.e. `--nb-cars`.
/// Number of cars
#[clap(short = 'c', long)]
nb_cars: Option<i32>,
/// admin_level to consider
#[clap(short, long)]
level: Vec<String>,
/// Files to process
#[clap(name = "FILE", parse(from_os_str), value_hint = ValueHint::AnyPath)]
files: Vec<PathBuf>,
}
fn main() {
let opt = Opt::parse();
println!("{:#?}", opt);
}