Enum UsageErr 

#[non_exhaustive]
pub enum UsageErr {
    InvalidFlag {
        token: String,
        reason: String,
        span: SourceSpan,
        input: String,
    },
    MissingFlag(String),
    DuplicateFlag(String),
    MissingGroup {
        group: String,
        members: String,
    },
    InvalidInput(String, SourceSpan, NamedSource<String>),
    MissingArg(String),
    MissingSubcommand(String, String),
    ArgRequiresDoubleDash(String),
    Help(String),
    Version(String),
    Miette(MietteError),
    IO(Error),
    Strum(ParseError),
    FromUtf8Error(FromUtf8Error),
    TeraError(Error),
    KdlError(KdlError),
    FileError(Error, PathBuf),
    ShellError(String),
    VarArgTooFew {
        name: String,
        min: usize,
        got: usize,
    },
    VarArgTooMany {
        name: String,
        max: usize,
        got: usize,
    },
    VarFlagTooFew {
        name: String,
        min: usize,
        got: usize,
    },
    VarFlagTooMany {
        name: String,
        max: usize,
        got: usize,
    },
    InvalidPath(String),
    InvalidView(String),
    InvalidValue {
        name: String,
        value: String,
        reason: String,
    },
    UnsupportedShell(String),
    MissingMountOutput(String),
}

Everything that can go wrong reading a spec or a command line against one.

#[non_exhaustive], so a caller matching on it needs a _ arm. That is the point: this enum grows every time the spec learns to say something new — MissingGroup arrived with groups, ArgRequiresDoubleDash with double_dash — and without this each one is a major release for everyone downstream.

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.

InvalidFlag

Fields

token: String

reason: String

span: SourceSpan

input: String

MissingFlag(String)

DuplicateFlag(String)

MissingGroup

A required group had none of its members given.

Its own variant rather than a UsageErr::MissingFlag holding a sentence, because there is no one flag to name: the group is the thing that was not satisfied, and a caller that renders errors itself needs the members as members.

Fields

group: String

members: String

InvalidInput(String, SourceSpan, NamedSource<String>)

MissingArg(String)

MissingSubcommand(String, String)

A command that declares subcommand_required was given none.

The spec could say this and the parser did not read it, so mise generate — which declares it — parsed as though it were a complete invocation. usage-argv and clap both refuse it.

ArgRequiresDoubleDash(String)

Help(String)

Version(String)

Miette(MietteError)

IO(Error)

Strum(ParseError)

FromUtf8Error(FromUtf8Error)

TeraError(Error)

KdlError(KdlError)

FileError(Error, PathBuf)

A file the spec model was asked to read could not be read.

Carries the path as well as the io error: “No such file or directory” on its own names nothing, and this is reported for spec files given on a command line.

ShellError(String)

A run= script could not be run, exited non-zero, or produced output usage could not read. The message names the shell and the script.

VarArgTooFew

Fields

name: String

min: usize

got: usize

VarArgTooMany

Fields

name: String

max: usize

got: usize

VarFlagTooFew

Fields

name: String

min: usize

got: usize

VarFlagTooMany

Fields

name: String

max: usize

got: usize

InvalidPath(String)

InvalidView(String)

InvalidValue

Fields

name: String

value: String

reason: String

UnsupportedShell(String)

MissingMountOutput(String)

Trait Implementations

impl Debug for UsageErr

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

Formats the value using the given formatter.

impl Diagnostic for UsageErr

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 severity(&self) -> Option<Severity>

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

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

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

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

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

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

Additional related Diagnostics.

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

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

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

The cause of the error.

impl Display for UsageErr

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

Formats the value using the given formatter.

impl Error for UsageErr

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 UsageErr

fn from(source: Error) -> Self

Converts to this type from the input type.

impl From<Error> for UsageErr

fn from(source: Error) -> Self

Converts to this type from the input type.

impl From<FromUtf8Error> for UsageErr

fn from(source: FromUtf8Error) -> Self

Converts to this type from the input type.

impl From<KdlError> for UsageErr

fn from(source: KdlError) -> Self

Converts to this type from the input type.

impl From<MietteError> for UsageErr

fn from(source: MietteError) -> Self

Converts to this type from the input type.

impl From<ParseError> for UsageErr

fn from(source: ParseError) -> Self

Converts to this type from the input type.