Struct OptionSpec 

pub struct OptionSpec { /* private fields */ }

One option a pass takes: its key, whether it is needed, an example value and what it means. Built only by its constructors, so a required option always has its example and an optional one always says what its absence means.

Implementations

impl OptionSpec

pub const fn required( key: &'static str, example: &'static str, doc: &'static str, ) -> Self

An option a pipeline must give.

pub const fn optional( key: &'static str, example: &'static str, doc: &'static str, absent: &'static str, ) -> Self

An option a pipeline may give; absent says what no value means (the registry refuses an empty one). Its example only documents it: optional options may exclude each other (at=centre or east and north), so the registry makes no pass from them.

pub const fn one_of( group: &'static str, key: &'static str, example: &'static str, doc: &'static str, ) -> Self

One of the options of group, of which a pipeline gives exactly one.

pub const fn one_of_choice<T: Choice>( group: &'static str, key: &'static str, doc: &'static str, ) -> Self

One of the options of group, of which a pipeline gives exactly one, whose value is one of T’s; the example is the first. Read by Given::optional_choice.

pub const fn choice<T: Choice>(key: &'static str, doc: &'static str) -> Self

A required option whose value is one of T’s; the example is the first.

pub const fn optional_choice<T: Choice>( key: &'static str, doc: &'static str, absent: &'static str, ) -> Self

An optional option whose value, when given, is one of T’s; absent says what no value means.

pub fn key(&self) -> &'static str

pub fn example(&self) -> &'static str

pub fn doc(&self) -> &'static str

pub fn absent(&self) -> Option<&'static str>

What no value means, for an optional option.

pub fn is_needed(&self) -> bool

Whether a pipeline must give it (alone, or as one of its group).

pub fn group(&self) -> Option<&'static str>

The group it is one of, if it is.

pub fn values(&self) -> Option<Vec<&'static str>>

The texts of its values, for a choice option.

Trait Implementations

impl Clone for OptionSpec

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for OptionSpec

impl Debug for OptionSpec

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

Formats the value using the given formatter.