Trait CombineErrors 

pub trait CombineErrors {
    type Ok;
    type Error;

    // Required method
    fn combine_errors(self) -> Result<Self::Ok, ErrorStream<Self::Error>>;
}

A trait for converting a tuple of Result<_, ErrorStream<_>>s into a Result of a tuple or combined ErrorStream.

Required Associated Types

type Ok

The type of the output if all results are Ok.

type Error

The type of the output if any result is Err.

Required Methods

fn combine_errors(self) -> Result<Self::Ok, ErrorStream<Self::Error>>

Combine errors from multiple places into one. This can be thought of as a kind of parallel ?.

If your goal is to show the user as many errors as possible, you should call this as late as possible, on as wide a tuple as you can.

Example usage:

use spacetimedb_data_structures::error_stream::{ErrorStream, CombineErrors};

struct MyError { cause: String };

fn age() -> Result<i32, ErrorStream<MyError>> {
    //...
}

fn name() -> Result<String, ErrorStream<MyError>> {
    // ...
}

fn likes_dogs() -> Result<bool, ErrorStream<MyError>> {
    // ...
}

fn description() -> Result<String, ErrorStream<MyError>> {
    // A typical usage of the API:
    // Collect multiple `Result`s in parallel, only using
    // `.combine_errors()?` once no more progress can be made.
    let (age, name, likes_dogs) =
        (age(), name(), likes_dogs()).combine_errors()?;

    Ok(format!(
        "{} is {} years old and {}",
        name,
        age,
        if likes_dogs { "likes dogs" } else { "does not like dogs" }
    ))
}

Implementations on Foreign Types

impl<T1, T2, E> CombineErrors for (Result<T1, ErrorStream<E>>, Result<T2, ErrorStream<E>>)

type Ok = (T1, T2)

type Error = E

fn combine_errors(self) -> Result<Self::Ok, ErrorStream<Self::Error>>

impl<T1, T2, T3, E> CombineErrors for (Result<T1, ErrorStream<E>>, Result<T2, ErrorStream<E>>, Result<T3, ErrorStream<E>>)

type Ok = (T1, T2, T3)

type Error = E

fn combine_errors(self) -> Result<Self::Ok, ErrorStream<Self::Error>>

impl<T1, T2, T3, T4, E> CombineErrors for (Result<T1, ErrorStream<E>>, Result<T2, ErrorStream<E>>, Result<T3, ErrorStream<E>>, Result<T4, ErrorStream<E>>)

type Ok = (T1, T2, T3, T4)

type Error = E

fn combine_errors(self) -> Result<Self::Ok, ErrorStream<Self::Error>>

impl<T1, T2, T3, T4, T5, E> CombineErrors for (Result<T1, ErrorStream<E>>, Result<T2, ErrorStream<E>>, Result<T3, ErrorStream<E>>, Result<T4, ErrorStream<E>>, Result<T5, ErrorStream<E>>)

type Ok = (T1, T2, T3, T4, T5)

type Error = E

fn combine_errors(self) -> Result<Self::Ok, ErrorStream<Self::Error>>

impl<T1, T2, T3, T4, T5, T6, E> CombineErrors for (Result<T1, ErrorStream<E>>, Result<T2, ErrorStream<E>>, Result<T3, ErrorStream<E>>, Result<T4, ErrorStream<E>>, Result<T5, ErrorStream<E>>, Result<T6, ErrorStream<E>>)

type Ok = (T1, T2, T3, T4, T5, T6)

type Error = E

fn combine_errors(self) -> Result<Self::Ok, ErrorStream<Self::Error>>

impl<T1, T2, T3, T4, T5, T6, T7, E> CombineErrors for (Result<T1, ErrorStream<E>>, Result<T2, ErrorStream<E>>, Result<T3, ErrorStream<E>>, Result<T4, ErrorStream<E>>, Result<T5, ErrorStream<E>>, Result<T6, ErrorStream<E>>, Result<T7, ErrorStream<E>>)

type Ok = (T1, T2, T3, T4, T5, T6, T7)

type Error = E

fn combine_errors(self) -> Result<Self::Ok, ErrorStream<Self::Error>>

impl<T1, T2, T3, T4, T5, T6, T7, T8, E> CombineErrors for (Result<T1, ErrorStream<E>>, Result<T2, ErrorStream<E>>, Result<T3, ErrorStream<E>>, Result<T4, ErrorStream<E>>, Result<T5, ErrorStream<E>>, Result<T6, ErrorStream<E>>, Result<T7, ErrorStream<E>>, Result<T8, ErrorStream<E>>)

type Ok = (T1, T2, T3, T4, T5, T6, T7, T8)

type Error = E

fn combine_errors(self) -> Result<Self::Ok, ErrorStream<Self::Error>>

impl<T1, T2, T3, T4, T5, T6, T7, T8, T9, E> CombineErrors for (Result<T1, ErrorStream<E>>, Result<T2, ErrorStream<E>>, Result<T3, ErrorStream<E>>, Result<T4, ErrorStream<E>>, Result<T5, ErrorStream<E>>, Result<T6, ErrorStream<E>>, Result<T7, ErrorStream<E>>, Result<T8, ErrorStream<E>>, Result<T9, ErrorStream<E>>)

type Ok = (T1, T2, T3, T4, T5, T6, T7, T8, T9)

type Error = E

fn combine_errors(self) -> Result<Self::Ok, ErrorStream<Self::Error>>

impl<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, E> CombineErrors for (Result<T1, ErrorStream<E>>, Result<T2, ErrorStream<E>>, Result<T3, ErrorStream<E>>, Result<T4, ErrorStream<E>>, Result<T5, ErrorStream<E>>, Result<T6, ErrorStream<E>>, Result<T7, ErrorStream<E>>, Result<T8, ErrorStream<E>>, Result<T9, ErrorStream<E>>, Result<T10, ErrorStream<E>>)

type Ok = (T1, T2, T3, T4, T5, T6, T7, T8, T9, T10)

type Error = E

fn combine_errors(self) -> Result<Self::Ok, ErrorStream<Self::Error>>

impl<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, E> CombineErrors for (Result<T1, ErrorStream<E>>, Result<T2, ErrorStream<E>>, Result<T3, ErrorStream<E>>, Result<T4, ErrorStream<E>>, Result<T5, ErrorStream<E>>, Result<T6, ErrorStream<E>>, Result<T7, ErrorStream<E>>, Result<T8, ErrorStream<E>>, Result<T9, ErrorStream<E>>, Result<T10, ErrorStream<E>>, Result<T11, ErrorStream<E>>)

type Ok = (T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11)

type Error = E

fn combine_errors(self) -> Result<Self::Ok, ErrorStream<Self::Error>>

impl<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, E> CombineErrors for (Result<T1, ErrorStream<E>>, Result<T2, ErrorStream<E>>, Result<T3, ErrorStream<E>>, Result<T4, ErrorStream<E>>, Result<T5, ErrorStream<E>>, Result<T6, ErrorStream<E>>, Result<T7, ErrorStream<E>>, Result<T8, ErrorStream<E>>, Result<T9, ErrorStream<E>>, Result<T10, ErrorStream<E>>, Result<T11, ErrorStream<E>>, Result<T12, ErrorStream<E>>)

type Ok = (T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12)

type Error = E

fn combine_errors(self) -> Result<Self::Ok, ErrorStream<Self::Error>>

Implementors