Struct knightrs::Function

pub struct Function { /* fields omitted */ }

The type that represents functions themselves (eg PROMPT, +, =, etc.) within Knight.

Note that Functions cannot be created directly—you must fetch them. New functions can be registered if so desired.

Implementations

impl Function

#[must_use]

pub fn func(
    &self
) -> fn(_: &[Value], _: &mut Environment<'_, '_, '_>) -> Result<Value, Error>

Gets the function pointer associated with self.

pub fn run(
    &self,
    args: &[Value],
    env: &mut Environment<'_, '_, '_>
) -> Result<Value, Error>

Executes this function with the given arguments

#[must_use]

pub fn arity(&self) -> usize

Gets the arity of this function.

#[must_use]

pub fn name(&self) -> char

Gets the name of the function.

#[must_use = "fetching a function does nothing by itself"]

pub fn fetch(name: char) -> Option<Self>

Gets the function associate dwith the given name, returning None if no such function exists.

pub fn register(
    name: char,
    arity: usize,
    func: fn(_: &[Value], _: &mut Environment<'_, '_, '_>) -> Result<Value, Error>
)

Registers a new function with the given name, discarding any previous value associated with it.

Trait Implementations

impl Clone for Function

fn clone(&self) -> Function

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Copy for Function

impl Debug for Function

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

Formats the value using the given formatter.

impl Eq for Function

impl Hash for Function

fn hash<H: Hasher>(&self, h: &mut H)

Feeds this value into the given Hasher.

pub fn hash_slice<H>(data: &[Self], state: &mut H) where
    H: Hasher, 

Feeds a slice of this type into the given Hasher.

impl PartialEq<Function> for Function

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

Checks to see if two functions are identical.

Two functions are considered the same if their names, arities, and function pointers are identical.

#[must_use]

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

This method tests for !=.