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Diffstat (limited to 'vendor/clap_builder/src/derive.rs')
| -rw-r--r-- | vendor/clap_builder/src/derive.rs | 361 |
1 files changed, 361 insertions, 0 deletions
diff --git a/vendor/clap_builder/src/derive.rs b/vendor/clap_builder/src/derive.rs new file mode 100644 index 0000000..7494e84 --- /dev/null +++ b/vendor/clap_builder/src/derive.rs @@ -0,0 +1,361 @@ +//! This module contains traits that are usable with the `#[derive(...)]` +//! macros in `clap_derive`. + +use crate::builder::PossibleValue; +use crate::{ArgMatches, Command, Error}; + +use std::ffi::OsString; + +/// Parse command-line arguments into `Self`. +/// +/// The primary one-stop-shop trait used to create an instance of a `clap` +/// [`Command`], conduct the parsing, and turn the resulting [`ArgMatches`] back +/// into concrete instance of the user struct. +/// +/// This trait is primarily a convenience on top of [`FromArgMatches`] + +/// [`CommandFactory`] which uses those two underlying traits to build the two +/// fundamental functions `parse` which uses the `std::env::args_os` iterator, +/// and `parse_from` which allows the consumer to supply the iterator (along +/// with fallible options for each). +/// +/// See also [`Subcommand`] and [`Args`]. +/// +/// **NOTE:** Deriving requires the `derive` feature flag +pub trait Parser: FromArgMatches + CommandFactory + Sized { + /// Parse from `std::env::args_os()`, exit on error + fn parse() -> Self { + let mut matches = <Self as CommandFactory>::command().get_matches(); + let res = <Self as FromArgMatches>::from_arg_matches_mut(&mut matches) + .map_err(format_error::<Self>); + match res { + Ok(s) => s, + Err(e) => { + // Since this is more of a development-time error, we aren't doing as fancy of a quit + // as `get_matches` + e.exit() + } + } + } + + /// Parse from `std::env::args_os()`, return Err on error. + fn try_parse() -> Result<Self, Error> { + let mut matches = ok!(<Self as CommandFactory>::command().try_get_matches()); + <Self as FromArgMatches>::from_arg_matches_mut(&mut matches).map_err(format_error::<Self>) + } + + /// Parse from iterator, exit on error + fn parse_from<I, T>(itr: I) -> Self + where + I: IntoIterator<Item = T>, + T: Into<OsString> + Clone, + { + let mut matches = <Self as CommandFactory>::command().get_matches_from(itr); + let res = <Self as FromArgMatches>::from_arg_matches_mut(&mut matches) + .map_err(format_error::<Self>); + match res { + Ok(s) => s, + Err(e) => { + // Since this is more of a development-time error, we aren't doing as fancy of a quit + // as `get_matches_from` + e.exit() + } + } + } + + /// Parse from iterator, return Err on error. + fn try_parse_from<I, T>(itr: I) -> Result<Self, Error> + where + I: IntoIterator<Item = T>, + T: Into<OsString> + Clone, + { + let mut matches = ok!(<Self as CommandFactory>::command().try_get_matches_from(itr)); + <Self as FromArgMatches>::from_arg_matches_mut(&mut matches).map_err(format_error::<Self>) + } + + /// Update from iterator, exit on error + fn update_from<I, T>(&mut self, itr: I) + where + I: IntoIterator<Item = T>, + T: Into<OsString> + Clone, + { + let mut matches = <Self as CommandFactory>::command_for_update().get_matches_from(itr); + let res = <Self as FromArgMatches>::update_from_arg_matches_mut(self, &mut matches) + .map_err(format_error::<Self>); + if let Err(e) = res { + // Since this is more of a development-time error, we aren't doing as fancy of a quit + // as `get_matches_from` + e.exit() + } + } + + /// Update from iterator, return Err on error. + fn try_update_from<I, T>(&mut self, itr: I) -> Result<(), Error> + where + I: IntoIterator<Item = T>, + T: Into<OsString> + Clone, + { + let mut matches = + ok!(<Self as CommandFactory>::command_for_update().try_get_matches_from(itr)); + <Self as FromArgMatches>::update_from_arg_matches_mut(self, &mut matches) + .map_err(format_error::<Self>) + } +} + +/// Create a [`Command`] relevant for a user-defined container. +/// +/// Derived as part of [`Parser`]. +pub trait CommandFactory: Sized { + /// Build a [`Command`] that can instantiate `Self`. + /// + /// See [`FromArgMatches::from_arg_matches_mut`] for instantiating `Self`. + fn command() -> Command; + /// Build a [`Command`] that can update `self`. + /// + /// See [`FromArgMatches::update_from_arg_matches_mut`] for updating `self`. + fn command_for_update() -> Command; +} + +/// Converts an instance of [`ArgMatches`] to a user-defined container. +/// +/// Derived as part of [`Parser`], [`Args`], and [`Subcommand`]. +pub trait FromArgMatches: Sized { + /// Instantiate `Self` from [`ArgMatches`], parsing the arguments as needed. + /// + /// Motivation: If our application had two CLI options, `--name + /// <STRING>` and the flag `--debug`, we may create a struct as follows: + /// + /// ```rust + /// # #[cfg(feature = "derive")] { + /// struct Context { + /// name: String, + /// debug: bool + /// } + /// # } + /// ``` + /// + /// We then need to convert the `ArgMatches` that `clap` generated into our struct. + /// `from_arg_matches` serves as the equivalent of: + /// + /// ```rust + /// # #[cfg(feature = "derive")] { + /// # use clap::ArgMatches; + /// # struct Context { + /// # name: String, + /// # debug: bool + /// # } + /// impl From<ArgMatches> for Context { + /// fn from(m: ArgMatches) -> Self { + /// Context { + /// name: m.get_one::<String>("name").unwrap().clone(), + /// debug: m.get_flag("debug"), + /// } + /// } + /// } + /// # } + /// ``` + fn from_arg_matches(matches: &ArgMatches) -> Result<Self, Error>; + + /// Instantiate `Self` from [`ArgMatches`], parsing the arguments as needed. + /// + /// Motivation: If our application had two CLI options, `--name + /// <STRING>` and the flag `--debug`, we may create a struct as follows: + /// + /// ```rust + /// # #[cfg(feature = "derive")] { + /// struct Context { + /// name: String, + /// debug: bool + /// } + /// # } + /// ``` + /// + /// We then need to convert the `ArgMatches` that `clap` generated into our struct. + /// `from_arg_matches_mut` serves as the equivalent of: + /// + /// ```rust + /// # #[cfg(feature = "derive")] { + /// # use clap::ArgMatches; + /// # struct Context { + /// # name: String, + /// # debug: bool + /// # } + /// impl From<ArgMatches> for Context { + /// fn from(m: ArgMatches) -> Self { + /// Context { + /// name: m.get_one::<String>("name").unwrap().to_string(), + /// debug: m.get_flag("debug"), + /// } + /// } + /// } + /// # } + /// ``` + fn from_arg_matches_mut(matches: &mut ArgMatches) -> Result<Self, Error> { + Self::from_arg_matches(matches) + } + + /// Assign values from `ArgMatches` to `self`. + fn update_from_arg_matches(&mut self, matches: &ArgMatches) -> Result<(), Error>; + + /// Assign values from `ArgMatches` to `self`. + fn update_from_arg_matches_mut(&mut self, matches: &mut ArgMatches) -> Result<(), Error> { + self.update_from_arg_matches(matches) + } +} + +/// Parse a set of arguments into a user-defined container. +/// +/// Implementing this trait lets a parent container delegate argument parsing behavior to `Self`. +/// with: +/// - `#[command(flatten)] args: ChildArgs`: Attribute can only be used with struct fields that impl +/// `Args`. +/// - `Variant(ChildArgs)`: No attribute is used with enum variants that impl `Args`. +/// +/// **NOTE:** Deriving requires the `derive` feature flag +pub trait Args: FromArgMatches + Sized { + /// Report the [`ArgGroup::id`][crate::ArgGroup::id] for this set of arguments + fn group_id() -> Option<crate::Id> { + None + } + /// Append to [`Command`] so it can instantiate `Self`. + /// + /// See also [`CommandFactory`]. + fn augment_args(cmd: Command) -> Command; + /// Append to [`Command`] so it can update `self`. + /// + /// This is used to implement `#[command(flatten)]` + /// + /// See also [`CommandFactory`]. + fn augment_args_for_update(cmd: Command) -> Command; +} + +/// Parse a sub-command into a user-defined enum. +/// +/// Implementing this trait lets a parent container delegate subcommand behavior to `Self`. +/// with: +/// - `#[command(subcommand)] field: SubCmd`: Attribute can be used with either struct fields or enum +/// variants that impl `Subcommand`. +/// - `#[command(flatten)] Variant(SubCmd)`: Attribute can only be used with enum variants that impl +/// `Subcommand`. +/// +/// **NOTE:** Deriving requires the `derive` feature flag +pub trait Subcommand: FromArgMatches + Sized { + /// Append to [`Command`] so it can instantiate `Self`. + /// + /// See also [`CommandFactory`]. + fn augment_subcommands(cmd: Command) -> Command; + /// Append to [`Command`] so it can update `self`. + /// + /// This is used to implement `#[command(flatten)]` + /// + /// See also [`CommandFactory`]. + fn augment_subcommands_for_update(cmd: Command) -> Command; + /// Test whether `Self` can parse a specific subcommand + fn has_subcommand(name: &str) -> bool; +} + +/// Parse arguments into enums. +/// +/// When deriving [`Parser`], a field whose type implements `ValueEnum` can have the attribute +/// `#[arg(value_enum)]` which will +/// - Call [`EnumValueParser`][crate::builder::EnumValueParser] +/// - Allowing using the `#[arg(default_value_t)]` attribute without implementing `Display`. +/// +/// **NOTE:** Deriving requires the `derive` feature flag +pub trait ValueEnum: Sized + Clone { + /// All possible argument values, in display order. + fn value_variants<'a>() -> &'a [Self]; + + /// Parse an argument into `Self`. + fn from_str(input: &str, ignore_case: bool) -> Result<Self, String> { + Self::value_variants() + .iter() + .find(|v| { + v.to_possible_value() + .expect("ValueEnum::value_variants contains only values with a corresponding ValueEnum::to_possible_value") + .matches(input, ignore_case) + }) + .cloned() + .ok_or_else(|| format!("invalid variant: {input}")) + } + + /// The canonical argument value. + /// + /// The value is `None` for skipped variants. + fn to_possible_value(&self) -> Option<PossibleValue>; +} + +impl<T: Parser> Parser for Box<T> { + fn parse() -> Self { + Box::new(<T as Parser>::parse()) + } + + fn try_parse() -> Result<Self, Error> { + <T as Parser>::try_parse().map(Box::new) + } + + fn parse_from<I, It>(itr: I) -> Self + where + I: IntoIterator<Item = It>, + It: Into<OsString> + Clone, + { + Box::new(<T as Parser>::parse_from(itr)) + } + + fn try_parse_from<I, It>(itr: I) -> Result<Self, Error> + where + I: IntoIterator<Item = It>, + It: Into<OsString> + Clone, + { + <T as Parser>::try_parse_from(itr).map(Box::new) + } +} + +impl<T: CommandFactory> CommandFactory for Box<T> { + fn command<'help>() -> Command { + <T as CommandFactory>::command() + } + fn command_for_update<'help>() -> Command { + <T as CommandFactory>::command_for_update() + } +} + +impl<T: FromArgMatches> FromArgMatches for Box<T> { + fn from_arg_matches(matches: &ArgMatches) -> Result<Self, Error> { + <T as FromArgMatches>::from_arg_matches(matches).map(Box::new) + } + fn from_arg_matches_mut(matches: &mut ArgMatches) -> Result<Self, Error> { + <T as FromArgMatches>::from_arg_matches_mut(matches).map(Box::new) + } + fn update_from_arg_matches(&mut self, matches: &ArgMatches) -> Result<(), Error> { + <T as FromArgMatches>::update_from_arg_matches(self, matches) + } + fn update_from_arg_matches_mut(&mut self, matches: &mut ArgMatches) -> Result<(), Error> { + <T as FromArgMatches>::update_from_arg_matches_mut(self, matches) + } +} + +impl<T: Args> Args for Box<T> { + fn augment_args(cmd: Command) -> Command { + <T as Args>::augment_args(cmd) + } + fn augment_args_for_update(cmd: Command) -> Command { + <T as Args>::augment_args_for_update(cmd) + } +} + +impl<T: Subcommand> Subcommand for Box<T> { + fn augment_subcommands(cmd: Command) -> Command { + <T as Subcommand>::augment_subcommands(cmd) + } + fn augment_subcommands_for_update(cmd: Command) -> Command { + <T as Subcommand>::augment_subcommands_for_update(cmd) + } + fn has_subcommand(name: &str) -> bool { + <T as Subcommand>::has_subcommand(name) + } +} + +fn format_error<I: CommandFactory>(err: crate::Error) -> crate::Error { + let mut cmd = I::command(); + err.format(&mut cmd) +} |