Struct nu_protocol::Signature

pub struct Signature {
    pub name: String,
    pub usage: String,
    pub positional: Vec<(PositionalType, String)>,
    pub rest_positional: Option<(SyntaxShape, String)>,
    pub named: IndexMap<String, (NamedType, String)>,
    pub yields: Option<Type>,
    pub input: Option<Type>,
    pub is_filter: bool,
}

The full signature of a command. All commands have a signature similar to a function signature. Commands will use this information to register themselves with Nu’s core engine so that the command can be invoked, help can be displayed, and calls to the command can be error-checked.

Fields

name: String

The name of the command. Used when calling the command

usage: String

Usage instructions about the command

positional: Vec<(PositionalType, String)>

The list of positional arguments, both required and optional, and their corresponding types and help text

rest_positional: Option<(SyntaxShape, String)>

After the positional arguments, a catch-all for the rest of the arguments that might follow, their type, and help text

named: IndexMap<String, (NamedType, String)>

The named flags with corresponding type and help text

yields: Option<Type>

The type of values being sent out from the command into the pipeline, if any

input: Option<Type>

The type of values being read in from the pipeline into the command, if any

is_filter: bool

If the command is expected to filter data, or to consume it (as a sink)

Implementations

impl Signature

pub fn shift_positional(&mut self)

pub fn remove_named(&mut self, name: &str)

pub fn allowed(&self) -> Vec<String>

impl Signature

pub fn new(name: impl Into<String>) -> Signature

Create a new command signature with the given name

pub fn build(name: impl Into<String>) -> Signature

Create a new signature

pub fn desc(self, usage: impl Into<String>) -> Signature

Add a description to the signature

pub fn required(
    self,
    name: impl Into<String>,
    ty: impl Into<SyntaxShape>,
    desc: impl Into<String>
) -> Signature

Add a required positional argument to the signature

pub fn optional(
    self,
    name: impl Into<String>,
    ty: impl Into<SyntaxShape>,
    desc: impl Into<String>
) -> Signature

Add an optional positional argument to the signature

pub fn named(
    self,
    name: impl Into<String>,
    ty: impl Into<SyntaxShape>,
    desc: impl Into<String>,
    short: Option<char>
) -> Signature

Add an optional named flag argument to the signature

pub fn required_named(
    self,
    name: impl Into<String>,
    ty: impl Into<SyntaxShape>,
    desc: impl Into<String>,
    short: Option<char>
) -> Signature

Add a required named flag argument to the signature

pub fn switch(
    self,
    name: impl Into<String>,
    desc: impl Into<String>,
    short: Option<char>
) -> Signature

Add a switch to the signature

pub fn filter(self) -> Signature

Set the filter flag for the signature

pub fn rest(self, ty: SyntaxShape, desc: impl Into<String>) -> Signature

Set the type for the “rest” of the positional arguments Note: Not naming the field in your struct holding the rest values “rest”, can cause errors when deserializing

pub fn yields(self, ty: Type) -> Signature

Add a type for the output of the command to the signature

pub fn input(self, ty: Type) -> Signature

Add a type for the input of the command to the signature

pub fn get_shorts(&self) -> Vec<char>

Get list of the short-hand flags

Trait Implementations

impl Clone for Signature

fn clone(&self) -> Signature

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Signature

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for Signature

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error> where
    __D: Deserializer<'de>, 

Deserialize this value from the given Serde deserializer.

impl PartialEq<Signature> for Signature

fn eq(&self, other: &Self) -> bool

This method tests for self and other values to be equal, and is used by ==.

#[must_use]

fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl PrettyDebugWithSource for Signature

fn pretty_debug(&self, source: &str) -> DebugDocBuilder

Prepare a Signature for pretty-printing

fn refined_pretty_debug(
    &self,
    _refine: PrettyDebugRefineKind,
    source: &str
) -> DebugDocBuilder

fn debug(&self, source: impl Into<Text>) -> String where
    Self: Clone, 

fn debuggable(self, source: impl Into<Text>) -> DebuggableWithSource<Self>

impl Serialize for Signature

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error> where
    __S: Serializer, 

Serialize this value into the given Serde serializer.

impl Eq for Signature