Module into_r 

Conversions from Rust types to R SEXP.

This module provides the IntoR trait for converting Rust values to R SEXPs.

Submodules

Module	Contents
large_integers	i64, u64, isize, usize → REALSXP, plus string/bool/Option scalars
collections	HashMap, BTreeMap, HashSet, BTreeSet → named/unnamed lists
result	Result<T, E> → list with ok/err fields
altrep	Altrep<T> marker type, Lazy<T> alias, IntoRAltrep trait

Thread Safety

The trait provides two methods:

• IntoR::into_sexp - checked version with debug thread assertions
• IntoR::into_sexp_unchecked - unchecked version for performance-critical paths

Use into_sexp_unchecked when you’re certain you’re on the main thread:

• Inside ALTREP callbacks
• Inside #[miniextendr(unsafe(main_thread))] functions
• Inside extern "C-unwind" functions called directly by R

Modules

altrep 🔒

ALTREP marker type (Altrep<T> / Lazy<T>).

collections 🔒

Collection conversions (HashMap, BTreeMap, HashSet, BTreeSet) to R.

large_integers 🔒

Large integer types → REALSXP (f64).

result 🔒

Result<T, E> conversions to R.

Macros

impl_into_r_via_coerce 🔒

Macro for infallible widening IntoR via Coerce.

impl_lossy_string_into_r 🔒

Generate IntoR impls for types with to_string_lossy() (owned scalar, ref scalar, Option, Vec, Vec). Used for PathBuf/&Path and OsString/&OsStr.

impl_option_collection_into_r 🔒

impl_scalar_into_r 🔒

Macro for scalar IntoR via Rf_Scalar* functions.

impl_set_coerce_into_r 🔒

Macro for HashSet<T>/BTreeSet<T> where T coerces to i32 (R’s native integer type).

impl_tuple_into_r 🔒

Macro to implement IntoR for tuples of various sizes. Converts Rust tuples to unnamed R lists (VECSXP).

impl_vec_coerce_into_r 🔒

Macro for Vec<T> where T coerces to a native R type.

impl_vec_map_into_r 🔒

impl_vec_option_coerce_into_r 🔒

Macro for Vec<Option<T>> where T coerces to a type with existing Option impl.

impl_vec_option_into_r 🔒

Macro for NA-aware Vec<Option<T>> → R vector conversions.

impl_vec_option_logical_into_r 🔒

impl_vec_option_smart_i64_into_r 🔒

Macro for NA-aware Vec<Option<T>> → R smart vector conversion. Checks if all non-None values fit i32 → INTSXP, otherwise REALSXP.

impl_vec_smart_i64_into_r 🔒

Structs

Altrep

NullOnErr

Marker type for Result<T, ()> that converts Err(()) to NULL.

Traits

IntoR

Trait for converting Rust types to R SEXP values.

IntoRAltrep

Extension trait for ALTREP conversions.

Functions

alloc_r_vector 🔒 ^⚠

Allocate an R vector of type T with n elements and return (SEXP, &mut [T]).

alloc_r_vector_unchecked 🔒 ^⚠

Allocate an R vector (unchecked FFI variant).

logical_iter_to_lglsxp 🔒

Helper: allocate LGLSXP and fill from an i32 iterator (checked).

logical_iter_to_lglsxp_unchecked 🔒 ^⚠

Helper: allocate LGLSXP and fill from an i32 iterator (unchecked).

str_iter_to_strsxp 🔒

Helper: allocate STRSXP and fill from a string iterator (checked).

str_iter_to_strsxp_unchecked 🔒 ^⚠

Helper: allocate STRSXP and fill from a string iterator (unchecked).

try_recover_cow_slice 🔒

Try SEXP pointer recovery for a borrowed Cow slice.

vec_of_into_r_to_list 🔒

Helper: convert a Vec of IntoR items to an R list (VECSXP).

vec_of_maps_to_list 🔒

Helper to convert a Vec of map-like types to an R list of named lists.

vec_to_sexp 🔒 ^⚠

Convert a slice to an R vector (checked) using copy_from_slice.

vec_to_sexp_unchecked 🔒 ^⚠

Convert a slice to an R vector (unchecked) using copy_from_slice.

Type Aliases

Lazy

Marker type to opt-in to ALTREP representation for types that have both eager-copy and ALTREP implementations.