Struct ArgParser

pub struct ArgParser {
    pub args: Vec<String>,
    /* private fields */
}

Our homebrewed Arg Parser

Fields

args: Vec<String>

Implementations

impl ArgParser

pub fn new(capacity: usize) -> Self

Create a new ArgParser object

The capacity specifies the initial capacity of the number parameters. Always good to set it at the number of flags and opts total. (Used for initial hashmap allocation size)

pub fn add_flag(self, flags: &[&str]) -> Self

Builder method for adding both short and long flags

Flags are just parameters that have no assigned values. They are used for when certain features or options have been enabled for the application

Examples

> ls -l --human-readable
  ^  ^  ^
  |  |  |
  |  |  `-- A long flag to enable human readable numbers.
  |  `-- A short flag to enable the long format.
  `-- The command to list files.

pub fn add_opt(self, short: &str, long: &str) -> Self

Builder method for adding both short and long opts

Opts are parameters that hold assigned values. They are used for when certain features or options have been enabled for the application

Examples

> ls -T 4 --color=always
  ^  ^    ^
  |  |    |
  |  |    `-- A long opt to enable the use of color with value `always`.
  |  `-- A short opt to set tab size to the value `4`.
  `-- The command to list files.

pub fn add_opt_default(self, short: &str, long: &str, default: &str) -> Self

Add an opt with a default value. Works the same way as add_opt.

pub fn add_setting(self, setting: &str) -> Self

Builder method for adding settings

Settings are parameters that hold assigned values. They are used in some applications such as dd

Examples

> dd if=/path/file
  ^  ^
  |  |
  |  |
  |  `-- The setting set to /path/file
  `-- The command to list files.

pub fn add_setting_default(self, setting: &str, default: &str) -> Self

Add a setting with a default value. Works the same way as add_setting

pub fn parse<A: Iterator<Item = String>>(&mut self, args: A)

Start parsing user inputted args for which flags and opts are used at runtime. The rest of the args that are not associated to opts get added to ArgParser.args.

pub fn count<P: Hash + Eq + ?Sized>(&self, name: &P) -> usize

where Param: Borrow<P>,

Get the number of times a flag or opt has been found after parsing.

pub fn found<P: Hash + Eq + ?Sized>(&self, name: &P) -> bool

where Param: Borrow<P>,

Check if a flag or opt has been found after initialization. While the short form of the opt or flag will be recognized, the long form should be used to enhance code readability.

Examples

if parser.found("my-long-flag") {
    //Do things...
}

pub fn flag<F: Hash + Eq + ?Sized>(&mut self, flag: &F) -> RefMut<'_, bool>

where Param: Borrow<F>,

Modify the state of a flag. Use true if the flag is to be enabled. Use false to disable its use.

pub fn opt<O: Hash + Eq + ?Sized>(&mut self, opt: &O) -> RefMut<'_, String>

where Param: Borrow<O>,

Modify the state value of an opt. Use Some(String) to set if the opt is to be enabled and has been assigned a value from String. Use None to disable the opt’s use.

pub fn get_opt<O: Hash + Eq + ?Sized>(&self, opt: &O) -> Option<String>

where Param: Borrow<O>,

Get the value of an Opt. If it has been set or defaulted, it will return a Some(String) value otherwise it will return None.

pub fn get_setting<O: Hash + Eq + ?Sized>(&self, setting: &O) -> Option<String>

where Param: Borrow<O>,

Get the value of an Setting. If it has been set or defaulted, it will return a Some(String) value otherwise it will return None.

pub fn found_invalid(&self) -> Result<(), String>

Trait Implementations

impl Clone for ArgParser

fn clone(&self) -> ArgParser

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for ArgParser

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

Formats the value using the given formatter.

impl Default for ArgParser

fn default() -> ArgParser

Returns the “default value” for a type.