Enum ConfigError 

#[non_exhaustive]
pub enum ConfigError {
    UnsupportedFormat(String),
    MissingExtension,
    MissingValue {
        field: String,
        span: Option<SourceSpan>,
    },
    TypeMismatch {
        field: String,
        expected: String,
        found: String,
        span: Option<SourceSpan>,
    },
    Nested {
        section: String,
        source: Box<dyn Diagnostic + Send + Sync>,
        span: Option<SourceSpan>,
    },
    Io(Error),
    Toml {
        source: Error,
        span: Option<SourceSpan>,
    },
}

Unified error returned by the runtime components.

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

UnsupportedFormat(String)

The format chosen by the caller or inferred from the extension is not supported.

MissingExtension

File paths without an extension cannot be parsed automatically.

MissingValue

Raised when a required value is not found during deserialization.

Fields

field: String

The field name that is missing

span: Option<SourceSpan>

Optional source span for where the error occurred

TypeMismatch

Raised when a value cannot be converted into the expected target type.

Fields

field: String

The field name that has the wrong type

expected: String

The expected type

found: String

The found value or type

span: Option<SourceSpan>

Optional source span highlighting the problematic value

Nested

Used to thread contextual errors when deserializing nested structs.

Fields

section: String

The section name that failed

source: Box<dyn Diagnostic + Send + Sync>

The underlying error

span: Option<SourceSpan>

Optional source span for the section

Io(Error)

IO errors propagated from the filesystem.

Toml

TOML parsing failure.

Fields

source: Error

The underlying toml error

span: Option<SourceSpan>

Optional source span for where the parse error occurred

Implementations

impl ConfigError

pub fn mismatch( field: impl Into<String>, expected: impl Into<String>, found: impl Into<String>, ) -> Self

Helper to produce a TypeMismatch error.

pub fn mismatch_at( field: impl Into<String>, expected: impl Into<String>, found: impl Into<String>, span: SourceSpan, ) -> Self

Helper to produce a TypeMismatch error with a source span.

pub fn nested(section: impl Into<String>, source: ConfigError) -> Self

Helper to wrap nested errors with additional context.

pub fn nested_at( section: impl Into<String>, source: ConfigError, span: SourceSpan, ) -> Self

Helper to wrap nested errors with additional context and a source span.

pub fn missing(key: impl Into<String>) -> Self

Helper to surface missing values.

pub fn missing_at(key: impl Into<String>, span: SourceSpan) -> Self

Helper to surface missing values with a source span.

Trait Implementations

impl Debug for ConfigError

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

Formats the value using the given formatter.

impl Diagnostic for ConfigError

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

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

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

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

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

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

The cause of the error.

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

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

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

Additional related Diagnostics.

impl Display for ConfigError

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

Formats the value using the given formatter.

impl Error for ConfigError

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 From<Error> for ConfigError

fn from(source: Error) -> Self

Converts to this type from the input type.