Trait redux_rs::Selector

pub trait Selector<State> {
    type Result;
    fn select(&self, state: &State) -> Self::Result;
}

Selector trait

Selectors are the way to get the current state and transform it into something useful for our app. You can write a selector by implementing the Selector trait or by writing a function with the signature Fn(&State) -> Result

Trait example

use redux_rs::Selector;

enum State {
    Authorized { bearer_token: String },
    Unauthorized
}

struct BearerTokenSelector;
impl Selector<State> for BearerTokenSelector {
    type Result = Option<String>;

    fn select(&self, state: &State) -> Self::Result {
        match state {
            State::Authorized { bearer_token } => Some(bearer_token.clone()),
            State::Unauthorized => None
        }
    }
}

let selector = BearerTokenSelector;
let state = State::Authorized { bearer_token: "secret".to_string() };
assert_eq!(selector.select(&state), Some("secret".to_string()));

Fn example

use redux_rs::Selector;

enum State {
    Authorized { bearer_token: String },
    Unauthorized
}

struct BearerTokenSelector;
impl Selector<State> for BearerTokenSelector {
    type Result = Option<String>;

    fn select(&self, state: &State) -> Self::Result {
        match state {
            State::Authorized { bearer_token } => Some(bearer_token.clone()),
            State::Unauthorized => None
        }
    }
}

let selector = |state: &State| {
    match state {
        State::Authorized { bearer_token } => Some(bearer_token.clone()),
        State::Unauthorized => None
    }
};
let state = State::Authorized { bearer_token: "secret".to_string() };
assert_eq!(selector.select(&state), Some("secret".to_string()));

Associated Types

type Result

Required methods

fn select(&self, state: &State) -> Self::Result

Implementors

impl<F, State, Result> Selector<State> for F where
    F: Fn(&State) -> Result, 

type Result = Result