Struct Args

pub struct Args { /* private fields */ }

A dead simple implementation of command line argument parsing and validation.

Implementations

impl Args

pub fn new(program_name: &str, description: &str) -> Args

Creates an empty set of command line options.

pub fn flag( &mut self, short_name: &str, long_name: &str, desc: &str, ) -> &mut Args

Registers an optional flag argument that does not take an argument and defaults to false.

• short_name - e.g. "h" for a -h option, or "" for none
• long_name - e.g. "help" for a --help option, or "" for none
• desc - A description of the flag for the usage message

pub fn full_usage(&self) -> String

Generates a combination of the short and verbose usage messages.

pub fn has_options(&self) -> bool

Returns a bool indicating whether or not any options are registered.

pub fn has_value(&self, opt_name: &str) -> bool

Returns a bool indicating whether or not a argument is present.

pub fn iter(&self) -> Iter<'_, String, String>

Returns an iterator visiting all key-value pairs in alphabetical order.

pub fn option( &mut self, short_name: &str, long_name: &str, desc: &str, hint: &str, occur: Occur, default: Option<String>, ) -> &mut Args

Registers an option explicitly.

• short_name - e.g. "h" for a -h option, or "" for none
• long_name - e.g. "help" for a --help option, or "" for none
• desc - A description of the flag for the usage message
• hint - A hint to be used in place of the argument in the usage message, e.g. "FILE" for a -o FILE option
• occur - An enum representing whether the option is required or not
• default - The default value for this option if there should be one

pub fn parse<C: IntoIterator>(&mut self, raw_args: C) -> Result<(), ArgsError>

where C::Item: AsRef<OsStr>,

Parses arguments according to the registered options.

Failures

Fails if any errors are encountered during parsing.

pub fn parse_from_cli(&mut self) -> Result<(), ArgsError>

Parses arguments directly from the command line according to the registered options.

Failures

Fails if any errors are encountered during parsing.

pub fn short_usage(&self) -> String

Generates a one-line usage summary from the registered options.

pub fn usage(&self) -> String

Generates a verbose usage summary from the registered options.

pub fn optional_validated_value_of<T>( &self, opt_name: &str, validations: &[Box<dyn Validation<T = T>>], ) -> Result<Option<T>, ArgsError>

where T: FromStr,

Retrieves the optional value of the Opt identified by opt_name, casts it to the type specified by T, runs all provided Validations, and wraps it in an Option.

Failures

See validated_value_of

pub fn optional_value_of<T: FromStr>( &self, opt_name: &str, ) -> Result<Option<T>, ArgsError>

Retrieves the optional value of the Opt identified by opt_name, casts it to the type specified by T and wraps it in an optional.

Failures

See value_of

pub fn validated_value_of<T>( &self, opt_name: &str, validations: &[Box<dyn Validation<T = T>>], ) -> Result<T, ArgsError>

where T: FromStr,

Retrieves the value of the Opt identified by opt_name, casts it to the type specified by T and then runs all provided Validations.

Failures

Returns Err(ArgsError) if no Opt correspond to opt_name, if the value cannot be cast to type T or if any validation is considered invalid.

pub fn value_of<T: FromStr>(&self, opt_name: &str) -> Result<T, ArgsError>

Retrieves the value for the Opt identified by opt_name and casts it to the type specified by T.

Failures

Returns Err(ArgsError) if no Opt corresponds to opt_name or if the value cannot be cast to type T.

pub fn values_of<T: FromStr>(&self, opt_name: &str) -> Result<Vec<T>, ArgsError>

Retrieves a vector of values for the Opt identified by opt_name and casts each of them to the type specified by T.

Failures

Returns Err(ArgsError) if no Opt corresponds to opt_name or if any of the values cannot be cast to type T.

pub fn get_option(&self, opt_name: &str) -> Option<Box<dyn Opt>>

Retreives an Option<Opt> for the Opt identified by opt_name

Failures

Returns None if no Opt corresponds to opt_name.

Trait Implementations

impl Display for Args

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

Formats the value using the given formatter.