Enum Error 

#[non_exhaustive]
pub enum Error {
    Parse(ParseError),
    Config(ConfigError),
    Spec(SpecError),
    Io(Error),
    IoAt {
        path: PathBuf,
        source: Error,
    },
    Formatter(String),
    LayoutTooWide {
        line_no: usize,
        width: usize,
        limit: usize,
    },
}

Errors that can be returned by parsing, config loading, spec loading, or formatting operations.

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.

Parse(ParseError)

A parser error annotated with source text and line-offset context.

Config(ConfigError)

A user config parse error.

Spec(SpecError)

A built-in or user override spec parse error.

Io(Error)

A filesystem or stream I/O failure where no path is attached. Use Error::io_at (or the IoResultExt::with_path adapter) when reporting an error against a specific file — the path-bearing variant is far more useful in user-facing diagnostics.

IoAt

A filesystem I/O failure annotated with the path that caused it. Used at every site where we have a path in scope; far more actionable than a bare permission denied from Error::Io.

Fields

path: PathBuf

The file or directory that failed.

source: Error

The underlying I/O error.

Formatter(String)

A higher-level formatter or CLI error that does not fit another structured variant. In practice this covers: runtime regex validation failures on a programmatically-built crate::Config (before the config is saved to disk), CLI argument validation failures, and rendering failures in the config/spec pretty-printers.

LayoutTooWide

A formatted line exceeded the configured line width and require_valid_layout is enabled.

Fields

line_no: usize

1-based line number in the formatted output.

width: usize

Actual character width of the offending line.

limit: usize

Configured crate::Config::line_width limit.

Implementations

impl Error

pub fn with_display_name(self, display_name: impl Into<String>) -> Self

Attach a human-facing source name (e.g. a file path) to a contextual ParseError. No-op for any other variant — Config, Spec, Io, IoAt, Formatter, and LayoutTooWide already carry the context they need and are returned unchanged.

pub fn io_at(path: impl Into<PathBuf>, source: Error) -> Self

Build an Error::IoAt variant from a path and an underlying io::Error. Use this at every I/O call site where you have a path in scope — Error::Io is reserved for streams (stdout, stdin) and similar path-less I/O.

Trait Implementations

impl Debug for Error

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

Formats the value using the given formatter.

impl Display for Error

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

Formats the value using the given formatter.

impl Error for 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 From<ConfigError> for Error

fn from(source: ConfigError) -> Self

Converts to this type from the input type.

impl From<Error> for Error

fn from(source: Error) -> Self

Converts to this type from the input type.

impl From<ParseError> for Error

fn from(source: ParseError) -> Self

Converts to this type from the input type.

impl From<SpecError> for Error

fn from(source: SpecError) -> Self

Converts to this type from the input type.