Trait evitable::ResultExt

pub trait ResultExt<T, E, C: ErrorContext>: OptionExt<T, C> {
    fn context_with(self, f: impl FnOnce(&E) -> C) -> Result<T, C::Error>;
}

Extension trait for result types (and other types carrying errors with them).

Required methods

fn context_with(self, f: impl FnOnce(&E) -> C) -> Result<T, C::Error>

Convert to a Result where ther error case is constructed from the given context factory which also accepts a reference to the original error.

Arguments

• f - Error context factory

Example

 #[evitable(description = "Error")]
 pub struct Context(String);

 // Later
 let io_error: std::io::Result<u8> = Err(io::Error::from(io::ErrorKind::NotFound));
 let io_ok: std::io::Result<u8> = Ok(42);

 // The functions here are called
 let error_with_source = io_error.context_with(|e| Context(format!("{:?}", e)));

 // The functions here will never be called
 let ok_result = io_ok.context_with(|e| Context(unimplemented!()));

 assert!(error_with_source.unwrap_err().source().is_some());

 ok_result.unwrap();

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Implementations on Foreign Types

impl<T, E: StdError + Send + Sync + 'static, C: ErrorContext> ResultExt<T, E, C> for Result<T, E>

fn context_with(self, f: impl FnOnce(&E) -> C) -> Result<T, C::Error>

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Implementors

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