Struct UnknownArgumentValueParser

pub struct UnknownArgumentValueParser { /* private fields */ }

When encountered, report ErrorKind::UnknownArgument

Useful to help users migrate, either from old versions or similar tools.

Examples

let cmd = Command::new("mycmd")
    .args([
        Arg::new("current-dir")
            .short('C'),
        Arg::new("current-dir-unknown")
            .long("cwd")
            .aliases(["current-dir", "directory", "working-directory", "root"])
            .value_parser(clap::builder::UnknownArgumentValueParser::suggest_arg("-C"))
            .hide(true),
    ]);

// Use a supported version of the argument
let matches = cmd.clone().try_get_matches_from(["mycmd", "-C", ".."]).unwrap();
assert!(matches.contains_id("current-dir"));
assert_eq!(
    matches.get_many::<String>("current-dir").unwrap_or_default().map(|v| v.as_str()).collect::<Vec<_>>(),
    vec![".."]
);

// Use one of the invalid versions
let err = cmd.try_get_matches_from(["mycmd", "--cwd", ".."]).unwrap_err();
assert_eq!(err.kind(), clap::error::ErrorKind::UnknownArgument);

Implementations

impl UnknownArgumentValueParser

pub fn suggest_arg(arg: impl Into<Str>) -> Self

Suggest an alternative argument

pub fn suggest(text: impl Into<StyledStr>) -> Self

Provide a general suggestion

pub fn and_suggest(self, text: impl Into<StyledStr>) -> Self

Extend the suggestions

Trait Implementations

impl Clone for UnknownArgumentValueParser

fn clone(&self) -> UnknownArgumentValueParser

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for UnknownArgumentValueParser

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl TypedValueParser for UnknownArgumentValueParser

type Value = String

Argument’s value type

fn parse_ref( &self, cmd: &Command, arg: Option<&Arg>, value: &OsStr, ) -> Result<Self::Value, Error>

Parse the argument value

fn parse_ref_( &self, cmd: &Command, arg: Option<&Arg>, _value: &OsStr, source: ValueSource, ) -> Result<Self::Value, Error>

Parse the argument value

fn parse( &self, cmd: &Command, arg: Option<&Arg>, value: OsString, ) -> Result<Self::Value, Error>

Parse the argument value

fn parse_( &self, cmd: &Command, arg: Option<&Arg>, value: OsString, _source: ValueSource, ) -> Result<Self::Value, Error>

Parse the argument value

fn possible_values( &self, ) -> Option<Box<dyn Iterator<Item = PossibleValue> + '_>>

Reflect on enumerated value properties

fn map<T, F>(self, func: F) -> MapValueParser<Self, F>

where T: Send + Sync + Clone, F: Fn(Self::Value) -> T + Clone,

Adapt a TypedValueParser from one value to another

fn try_map<T, E, F>(self, func: F) -> TryMapValueParser<Self, F>

where F: Fn(Self::Value) -> Result<T, E> + Clone + Send + Sync + 'static, T: Send + Sync + Clone, E: Into<Box<dyn Error + Send + Sync + 'static>>,

Adapt a TypedValueParser from one value to another

Layout

Note: Most layout information is completely unstable and may even differ between compilations. The only exception is types with certain repr(...) attributes. Please see the Rust Reference's “Type Layout” chapter for details on type layout guarantees.

Size: 40 bytes