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),
    InvalidOutput(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.

With the miette feature enabled, this implements miette::Diagnostic so applications can pass it directly to their existing miette reporter. The feature is disabled by default.

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)

InvalidOutput(String)

A command’s output/select declarations do not agree with each other, or with the flags around them. Spanless like UsageErr::InvalidView, because selection is resolved once the whole document is read — a select may name a flag declared on an ancestor, so the node spans are long gone by the time it can be checked.

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 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<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.

impl From<UsageErr> for Error

fn from(value: UsageErr) -> Self

Converts to this type from the input type.