Struct ArgError 

pub struct ArgError {
    param: String,
    message: String,
}

An argument error as a value: the parameter’s R name and the message. ArgError::raise raises it as the generated wrapper’s own argument error, through crate::arg_error!.

crate::match_arg_param returns it for a choice argument the body matches itself. Raise it where the argument is bad, or handle it:

use miniextendr_api::{SEXP, match_arg_param, miniextendr};

#[miniextendr]
pub fn prepare(data: SEXP, mode: SEXP) -> String {
    if is_data_frame(data) {
        let mode: Mode = match_arg_param(mode, "mode").unwrap_or_else(|e| e.raise());
        // ...
    }
    // ...
}

It does not implement RConditionData: returned as a body’s Err it would take the Result path (kind = "result_err"), not the argument error’s.

Fields

param: String

message: String

Implementations

impl ArgError

pub fn new(param: impl Into<String>, message: impl Into<String>) -> Self

The argument error of parameter param (its R name) with message, used as given.

pub fn param(&self) -> &str

The parameter’s R name (e$param).

pub fn message(&self) -> &str

The message (conditionMessage(e)).

pub fn raise(self) -> !

Raise it: arg_error!(param = <param>, "{}", <message>). The condition is the one the generated wrapper raises for that parameter; see crate::arg_error!.

Trait Implementations

impl Clone for ArgError

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for ArgError

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

Formats the value using the given formatter.

impl Display for ArgError

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

Formats the value using the given formatter.

impl Eq for ArgError

#[doc(hidden)]

fn assert_fields_are_eq(&self)

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

#[doc(hidden)]

fn assert_receiver_is_total_eq(&self)

👎Deprecated since 1.95.0:

implementation detail of #[derive(Eq)]

impl Error for ArgError

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

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

#[doc(hidden)]

fn type_id(&self, _: Internal) -> TypeId

where Self: 'static,

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

Gets the TypeId of self.

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 PartialEq for ArgError

fn eq(&self, other: &Self) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for ArgError

Layout

Note: Most layout information is completely unstable and may even differ between compilations. The only exception is types with certain repr(...) attributes. Please see the Rust Reference's “Type Layout” chapter for details on type layout guarantees.

Size: 48 bytes