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Diffstat (limited to 'vendor/clap/src/_derive/_tutorial/chapter_2.rs')
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diff --git a/vendor/clap/src/_derive/_tutorial/chapter_2.rs b/vendor/clap/src/_derive/_tutorial/chapter_2.rs new file mode 100644 index 000000000..95d02f851 --- /dev/null +++ b/vendor/clap/src/_derive/_tutorial/chapter_2.rs @@ -0,0 +1,103 @@ +//! ## Adding Arguments +//! +//! 1. [Positionals](#positionals) +//! 2. [Options](#options) +//! 3. [Flags](#flags) +//! 4. [Subcommands](#subcommands) +//! 5. [Defaults](#defaults) +//! +//! Arguments are inferred from the fields of your struct. +//! +//! ### Positionals +//! +//! You can have users specify values by their position on the command-line: +//! +//! ```rust +#![doc = include_str!("../../../examples/tutorial_derive/03_03_positional.rs")] +//! ``` +#![doc = include_str!("../../../examples/tutorial_derive/03_03_positional.md")] +//! +//! Note that the [default `ArgAction` is `Set`][super#arg-types]. To +//! accept multiple values, override the [action][Arg::action] with [`Append`][crate::ArgAction::Append] via `Vec`: +//! ```rust +#![doc = include_str!("../../../examples/tutorial_derive/03_03_positional_mult.rs")] +//! ``` +#![doc = include_str!("../../../examples/tutorial_derive/03_03_positional_mult.md")] +//! +//! ### Options +//! +//! You can name your arguments with a flag: +//! - Order doesn't matter +//! - They can be optional +//! - Intent is clearer +//! +//! To specify the flags for an argument, you can use [`#[arg(short = 'n')]`][Arg::short] and/or +//! [`#[arg(long = "name")]`][Arg::long] attributes on a field. When no value is given (e.g. +//! `#[arg(short)]`), the flag is inferred from the field's name. +//! +//! ```rust +#![doc = include_str!("../../../examples/tutorial_derive/03_02_option.rs")] +//! ``` +#![doc = include_str!("../../../examples/tutorial_derive/03_02_option.md")] +//! +//! Note that the [default `ArgAction` is `Set`][super#arg-types]. To +//! accept multiple occurrences, override the [action][Arg::action] with [`Append`][crate::ArgAction::Append] via `Vec`: +//! ```rust +#![doc = include_str!("../../../examples/tutorial_derive/03_02_option_mult.rs")] +//! ``` +#![doc = include_str!("../../../examples/tutorial_derive/03_02_option_mult.md")] +//! +//! ### Flags +//! +//! Flags can also be switches that can be on/off: +//! +//! ```rust +#![doc = include_str!("../../../examples/tutorial_derive/03_01_flag_bool.rs")] +//! ``` +#![doc = include_str!("../../../examples/tutorial_derive/03_01_flag_bool.md")] +//! +//! Note that the [default `ArgAction` for a `bool` field is +//! `SetTrue`][super#arg-types]. To accept multiple flags, override the [action][Arg::action] with +//! [`Count`][crate::ArgAction::Count]: +//! +//! ```rust +#![doc = include_str!("../../../examples/tutorial_derive/03_01_flag_count.rs")] +//! ``` +#![doc = include_str!("../../../examples/tutorial_derive/03_01_flag_count.md")] +//! +//! This also shows that any[`Arg`][crate::Args] method may be used as an attribute. +//! +//! ### Subcommands +//! +//! Subcommands are derived with `#[derive(Subcommand)]` and be added via +//! [`#[command(subcommand)]` attribute][super#command-attributes] on the field using that type. +//! Each instance of a [Subcommand][crate::Subcommand] can have its own version, author(s), Args, +//! and even its own subcommands. +//! +//! ```rust +#![doc = include_str!("../../../examples/tutorial_derive/03_04_subcommands.rs")] +//! ``` +//! We used a struct-variant to define the `add` subcommand. +//! Alternatively, you can use a struct for your subcommand's arguments: +//! ```rust +#![doc = include_str!("../../../examples/tutorial_derive/03_04_subcommands_alt.rs")] +//! ``` +//! +#![doc = include_str!("../../../examples/tutorial_derive/03_04_subcommands.md")] +//! +//! ### Defaults +//! +//! We've previously showed that arguments can be [`required`][crate::Arg::required] or optional. +//! When optional, you work with a `Option` and can `unwrap_or`. Alternatively, you can +//! set [`#[arg(default_value_t)]`][super#arg-attributes]. +//! +//! ```rust +#![doc = include_str!("../../../examples/tutorial_derive/03_05_default_values.rs")] +//! ``` +#![doc = include_str!("../../../examples/tutorial_derive/03_05_default_values.md")] +#![allow(unused_imports)] +use crate::builder::*; + +pub use super::chapter_1 as previous; +pub use super::chapter_3 as next; +pub use crate::_tutorial as table_of_contents; |