Trait janetrs::JanetArgs

pub trait JanetArgs {
    // Required methods
    fn get_value(&self, index: usize) -> Option<Janet>;
    fn get_tagged(&self, index: usize) -> Option<TaggedJanet<'_>>;

    // Provided methods
    fn get_matches(&self, index: usize, matches: &[JanetType]) -> Janet { ... }
    fn get_tagged_matches(
        &self,
        index: usize,
        matches: &[JanetType]
    ) -> TaggedJanet<'_> { ... }
    fn try_get<T>(&self, index: usize) -> Result<T, T::Error>
       where T: TryFrom<Janet> { ... }
    fn get_or<T>(&self, index: usize, default: T) -> T
       where T: TryFrom<Janet> { ... }
    fn get_or_default<T>(&self, index: usize) -> T
       where T: TryFrom<Janet> + Default { ... }
    fn get_or_else<T, F>(&self, index: usize, op: F) -> T
       where T: TryFrom<Janet>,
             F: FnOnce(T::Error) -> T { ... }
    fn get_opt<T>(&self, index: usize, default: T) -> T
       where T: TryFrom<Janet> + JanetTypeName { ... }
    fn get_or_panic<T>(&self, index: usize) -> T
       where T: TryFrom<Janet> + JanetTypeName { ... }
}

Trait that only exist to extend methods over [Janet] so it’s easier to get janet_fn args.

Required Methods

fn get_value(&self, index: usize) -> Option<Janet>

Get the argument at the index position.

fn get_tagged(&self, index: usize) -> Option<TaggedJanet<'_>>

Get the argument at the index position as the TaggedJanet type.

Provided Methods

fn get_matches(&self, index: usize, matches: &[JanetType]) -> Janet

Get the argument at the index position if they match one if the JanetType in matches, janet-panicking otherwise.

Janet Panics

This function may panic if the item at index does not match any of the JanetType in matches.

fn get_tagged_matches( &self, index: usize, matches: &[JanetType] ) -> TaggedJanet<'_>

Get the argument at the index position if they match one if the JanetType in matches as the TaggedJanet type, janet-panicking otherwise.

Janet Panics

This function may panic if the item at index does not match any of the JanetType in matches.

fn try_get<T>(&self, index: usize) -> Result<T, T::Error>

where T: TryFrom<Janet>,

Get the argument at the index position and tries to convert to T.

Examples

use janetrs::{janet_fn, Janet, JanetArgs};

// Lets say it's a function that if receives an argument, if is not the wanted type, it
// defaults to the given value.
#[janet_fn(arity(range(0, 1)))]
fn my_func(args: &mut [Janet]) -> Janet {
    let res = args.try_get::<i32>(0);

    // Rest of the function
    todo!()
}

fn get_or<T>(&self, index: usize, default: T) -> T

where T: TryFrom<Janet>,

Get the argument at the index position and convert to T, if that fails, returns the default value.

Examples

use janetrs::{janet_fn, Janet, JanetArgs};

// Lets say it's a function that if receives an argument, if is not the wanted type, it
// defaults to the given value.
#[janet_fn(arity(range(0, 1)))]
fn my_func(args: &mut [Janet]) -> Janet {
    let my_flag = args.get_or(0, false);

    // Rest of the function
    todo!()
}

fn get_or_default<T>(&self, index: usize) -> T

where T: TryFrom<Janet> + Default,

Get the argument at the index position and convert to T, if that fails, returns the Default::default value for T.

Examples

use janetrs::{janet_fn, Janet, JanetArgs};

// Lets say it's a function that if receives an argument, if is not the wanted type, it
// defaults to the given value.
#[janet_fn(arity(range(0, 1)))]
fn my_func(args: &mut [Janet]) -> Janet {
    let my_flag: i32 = args.get_or_default(0);

    // Rest of the function
    todo!()
}

fn get_or_else<T, F>(&self, index: usize, op: F) -> T

where T: TryFrom<Janet>, F: FnOnce(T::Error) -> T,

Get the argument at the index position and convert to T, if that fails, computes the value from a closure.

Examples

use janetrs::{janet_fn, Janet, JanetArgs};

// Lets say it's a function that if receives an argument, if is not the wanted type, it
// defaults to the given value.
#[janet_fn(arity(range(0, 1)))]
fn my_func(args: &mut [Janet]) -> Janet {
    let my_flag: i32 = args.get_or_else(0, |_| 10);

    // Rest of the function
    todo!()
}

fn get_opt<T>(&self, index: usize, default: T) -> T

where T: TryFrom<Janet> + JanetTypeName,

Get the argument at the index position, if it’s Janet nil, returns the default value, but janet panics if the the value is different than nil and fail to convert to T.

Janet Panics

This function may panic if the conversion fails.

Examples

use janetrs::{janet_fn, Janet, JanetArgs};

// Lets say it's a function that receives a second argument that change de behavior of
// the function
#[janet_fn(arity(range(1, 2)))]
fn my_func(args: &mut [Janet]) -> Janet {
    let my_flag = args.get_opt(1, false);

    // Rest of the function
    todo!()
}

fn get_or_panic<T>(&self, index: usize) -> T

where T: TryFrom<Janet> + JanetTypeName,

Get the argument at the index position and convert to T, if that fails, it janet panics.

Janet Panics

This function may panic if the conversion fails.

Examples

use janetrs::{janet_fn, Janet, JanetArgs, JanetString};

#[janet_fn(arity(fix(1)))]
fn my_func(args: &mut [Janet]) -> Janet {
    let my_str: JanetString = args.get_or_panic(0);

    // Rest of the function
    todo!()
}

Object Safety

This trait is not object safe.

Implementations on Foreign Types

impl JanetArgs for [Janet]

fn get_value(&self, index: usize) -> Option<Janet>

fn get_tagged(&self, index: usize) -> Option<TaggedJanet<'_>>

impl<const N: usize> JanetArgs for [Janet; N]

fn get_value(&self, index: usize) -> Option<Janet>

fn get_tagged(&self, index: usize) -> Option<TaggedJanet<'_>>

Implementors