Struct AsFromStr 

pub struct AsFromStr<T>(pub T);

Wrap a parsed T: FromStr from an R character scalar.

Pass an R character scalar and it will be parsed into T via str::parse(). NA_character_ is refused with SexpError::Na rather than parsed as "". A parse failure quotes the value: "not-an-ip": invalid IP address syntax.

For numbers read like R’s as.numeric() (from character, factor labels, or numbers, with NA as None), use AsNumeric instead.

Example

use std::net::IpAddr;

#[miniextendr]
fn check_ip(addr: AsFromStr<IpAddr>) -> bool {
    addr.0.is_loopback()
}
// R: check_ip("127.0.0.1") → TRUE

Tuple Fields

0: T

Trait Implementations

impl<T: Clone> Clone for AsFromStr<T>

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<T: Debug> Debug for AsFromStr<T>

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

Formats the value using the given formatter.

impl<T: Display> IntoR for AsFromStr<T>

The value’s Display text as a character scalar, which the marker parses back. A trait’s View passes an AsFromStr argument this way, so the value crosses unchanged when T::from_str(&t.to_string()) == t (the std numbers, IpAddr, Uuid, …). This IntoR exists for the trait ABI; to return text from a function, use AsDisplay.

type Error = <String as IntoR>::Error

The error type for fallible conversions.

fn try_into_sexp(self) -> Result<SEXP, Self::Error>

Try to convert this value to an R SEXP.

unsafe fn try_into_sexp_unchecked(self) -> Result<SEXP, Self::Error>

Try to convert to SEXP without thread safety checks.

fn into_sexp(self) -> SEXP

Convert this value to an R SEXP, panicking on error.

unsafe fn into_sexp_unchecked(self) -> SEXP

Convert to SEXP without thread safety checks, panicking on error.

impl<T: FromStr> TryFromSexp for AsFromStr<T>

where T::Err: Display,

const CHARACTER_ONLY: bool = true

Whether this conversion accepts only character input: every value it converts, other than NULL, is a character vector or a factor.

type Error = SexpError

The error type returned when conversion fails.

fn try_from_sexp(sexp: SEXP) -> Result<Self, Self::Error>

Attempt to convert an R SEXP to this Rust type.

const NATIVE_BORROW: Option<NativeBorrow> = None

Native vector storage retained by this conversion, if any.

#[doc(hidden)]

const __MX_EXPECTATION: Option<&'static str> = None

What an argument of this type must be, in R terms, when #[miniextendr] cannot tell from the type as written: the <expected> of a failed conversion’s '<p>' must be <expected>: ....

unsafe fn try_from_sexp_unchecked(sexp: SEXP) -> Result<Self, Self::Error>

Convert from SEXP without thread safety checks.

#[doc(hidden)]

unsafe fn __mx_try_from_rooted(root: Root<'_>) -> Result<Self, Self::Error>

Convert with a scope able to retain uncached ALTREP elements. Custom reference converters keep their existing behavior by default.

#[doc(hidden)]

fn __mx_has_na(&self) -> bool

Whether the converted argument holds a value #[miniextendr(no_na)] refuses after the conversion.

#[doc(hidden)]

fn __mx_input_has_na(&self, input: SEXP) -> bool

Whether #[miniextendr(no_na)] refuses this converted argument, read from input (the R value it converted from), when no R guard ran.

#[doc(hidden)]

fn __mx_try_from_sexp_with_check( sexp: SEXP, check: &ElementCheck<'_>, ) -> Result<Self, SexpError>

where Self::Error: Into<SexpError>,

Convert, running check, an element type’s TryFromSexpElement::check_sexp, on the R value that carries an element’s class (#1837).

#[doc(hidden)]

unsafe fn __mx_try_from_sexp_unchecked_with_check( sexp: SEXP, check: &ElementCheck<'_>, ) -> Result<Self, SexpError>

where Self::Error: Into<SexpError>,

__mx_try_from_sexp_with_check through try_from_sexp_unchecked. Not public API.

Layout

Note: Unable to compute type layout, possibly due to this type having generic parameters. Layout can only be computed for concrete, fully-instantiated types.