Struct Error 

pub struct Error<Kind = Never> { /* private fields */ }

A polymorphic error type that can optionally contain a strongly-typed kind for structural error handling (when an error needs to be matched on). It’s possible to construct it using just a message string and no kind.

See the various constructor method on this type and the Context extension trait for more details.

Implementations

impl<Kind> Error<Kind>

pub fn print(&self)

where Kind: Diagnostic,

Output the error to stderr. Use this to ultimately display it to the user in a top-level main function, for example.

pub fn kind(&self) -> Option<&Kind>

Get a reference to the error’s typed kind. If this contains an uncategorized error then None is returned.

pub fn from_kind(kind: Kind) -> Self

Create a new categorized error from the given kind.

pub fn wrap( source: impl Into<Box<dyn Error + Send + Sync>>, message: impl Into<String>, ) -> Self

Wrap an existing error making it a source of this error, and add more context with a message.

pub fn root(message: impl Into<String>) -> Self

Make a root error that doesn’t have a source error

pub fn try_many( errors: impl IntoIterator<Item = Self>, message: impl Into<String>, ) -> Result<(), Kind>

Accepts an iterator of errors and returns Ok if it is empty, otherwise returns a single Error if it contains exactly one error, and returns an error with many Errors inside if there are more than one.

pub fn many( errors: impl IntoIterator<Item = Error<Kind>>, message: impl Into<String>, ) -> Self

Many related errors happened. They don’t form the chain of causality, but they are related to each other.

pub fn transparent(error: impl Into<Box<dyn Error + Send + Sync>>) -> Self

Make an uncategorized error without any additional context that will just transparently wrap the given error.

Trait Implementations

impl<Kind> Debug for Error<Kind>

where Kind: Debug,

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

Formats the value using the given formatter.

impl<Kind> Diagnostic for Error<Kind>

where Kind: Diagnostic,

Forward the Diagnostic implementation to the categorized error.

fn code<'a>(&'a self) -> Option<Box<dyn Display + 'a>>

Unique diagnostic code that can be used to look up more information about this Diagnostic. Ideally also globally unique, and documented in the toplevel crate’s documentation for easy searching. Rust path format (foo::bar::baz) is recommended, but more classic codes like E0123 or enums will work just fine.

fn severity(&self) -> Option<Severity>

Diagnostic severity. This may be used by ReportHandlers to change the display format of this diagnostic.

fn help<'a>(&'a self) -> Option<Box<dyn Display + 'a>>

Additional help text related to this Diagnostic. Do you have any advice for the poor soul who’s just run into this issue?

fn url<'a>(&'a self) -> Option<Box<dyn Display + 'a>>

URL to visit for a more detailed explanation/help about this Diagnostic.

fn source_code(&self) -> Option<&dyn SourceCode>

Source code to apply this Diagnostic’s Diagnostic::labels to.

fn labels(&self) -> Option<Box<dyn Iterator<Item = LabeledSpan> + '_>>

Labels to apply to this Diagnostic’s Diagnostic::source_code

fn related<'a>( &'a self, ) -> Option<Box<dyn Iterator<Item = &'a dyn Diagnostic> + 'a>>

Additional related Diagnostics.

fn diagnostic_source(&self) -> Option<&dyn Diagnostic>

The cause of the error.

impl<Kind> Display for Error<Kind>

where Kind: Display,

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

Formats the value using the given formatter.

impl<Kind> Error for Error<Kind>

where Kind: Error,

fn source(&self) -> Option<&(dyn Error + 'static)>

Returns the lower-level source of this error, if any.

fn description(&self) -> &str

👎Deprecated since 1.42.0: use the Display impl or to_string()

fn cause(&self) -> Option<&dyn Error>

👎Deprecated since 1.33.0: replaced by Error::source, which can support downcasting

fn provide<'a>(&'a self, request: &mut Request<'a>)

🔬This is a nightly-only experimental API. (error_generic_member_access)

Provides type-based access to context intended for error reports.

impl<Kind> From<Kind> for Error<Kind>

fn from(value: Kind) -> Self

Converts to this type from the input type.